Tag: panthenol

Sensitive Skin Ingredients: The Category No Regulator Names, and Five with Human Studies

Hello, this is Dr. J. Today I want to pick five ingredients for sensitive skin the only way that is left — from studies done on people.

One thing first, because it sets up everything else. Sensitive skin barely appears in the rules at all. Where it does appear, it is not as something to measure. It is a reason to exclude someone from a test.

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The sources, first

📄 Regulation on Review of Functional Cosmetics, Annex 4 (Korean Law Service)

📄 MFDS, Guideline on Test Methods for Substantiating Cosmetic Claims (2018-03, PDF)

📄 U.S. FDA, “Hypoallergenic Cosmetics”

📄 Regulation (EC) No 1223/2009, Article 14

Six categories in the Korean annex, ten methods in the guideline. Sensitive skin is in neither.

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Five lines, if you are in a hurry

✔ Korea notifies actives in six categories, and sensitive skin is not one

✔ The MFDS test-method guideline lists ten methods, and sensitive skin is not one either

✔ In those tests, sensitive skin is an exclusion criterion

✔ The United States wrote a definition for “hypoallergenic” in 1975 and lost it in court

✔ So five ingredients are picked here from human studies, weaknesses included

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What Korea names, and what it leaves out

Korea’s functional cosmetics system works from a notified list. Annex 4 of the Regulation on Review of Functional Cosmetics sets out the ingredient and the amount. Make a product to those numbers and you do not have to file fresh efficacy data — which is another way of saying the state has already decided what counts.

Category	What the notification sets out	How to read it
UV protection	27 ingredients with maximum amounts	Names and numbers are both fixed
Brightening	Nine ingredients (arbutin 2–5%, niacinamide 2–5% and others)	Same
Wrinkle improvement	Four ingredients (retinol 2,500 IU/g, adenosine 0.04% and others)	Same
Hair colour change	A dyeing list split across six sub-tables	Same
Hair removal	Thioglycolic acid, 3.0–4.5% as the acid, pH 7.0 to under 12.7	One ingredient
Acne relief	Salicylic acid 0.5%, in cleansing products	One ingredient
Sensitive skin	Nothing	There is no such category

Acne gets one ingredient. Sensitive skin gets no category at all. So “for sensitive skin” and “low irritation” on a Korean box are not reviewed phrases.

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There is no method to measure it either

This is the part that is specific to Korea, and it is worth knowing if you sell there. The MFDS publishes a separate guideline that tells you how to run the test behind a claim — which instrument, how long, what unit. Each claim gets its own chapter.

Chapter	Test method	Added
1	Skin moisturising	2012-05, at issue
2	Skin elasticity	2012-05, at issue
3	Sebum control	2012-05, at issue
4	Temporary reduction of cellulite	2013-11
5	Suitability for acne-prone skin	2013-11
6	Dark circle improvement	2014-08
7	Skin blood-flow improvement	2015-12
8	Puffiness reduction	2015-12
9	Paraben-free	2017-03-31
10	Fine-dust blocking	2018-03-28
—	Sensitive skin, low irritation	Not among the ten

Moisturising is there. Sebum is there. Dark circles are there. Sensitive skin is not.

★ The one place “sensitive” does appear

In the subject-selection rules for chapters 1, 2 and 3 — moisturising, elasticity and sebum — one of the exclusion criteria is “people with sensitive or hyper-reactive skin”. Chapter 5, on acne-prone skin, excludes “people whose skin is sensitive to adhesive components”.
So in this document sensitive skin is not something you measure. It is something you screen out before you measure anything else.

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The United States tried, and the courts said no

The American story is the sharpest of the three, because the definition existed and then stopped existing.

When	What happened	Where it stands
February 1974	FDA proposed a regulation on the term hypoallergenic	A definition was on the table
6 June 1975	FDA issued the final regulation	Manufacturers would have had to test
On appeal	The court held FDA’s definition was unreasonable	The regulation fell
Today	«There are no Federal standards or definitions that govern the use»	«The term means whatever a particular company wants it to mean»

FDA’s own page puts it plainly: «There are no Federal standards or definitions that govern the use of the term “hypoallergenic.”» And then, one sentence later: «The term means whatever a particular company wants it to mean.»

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The EU names actives for three jobs, and claims are not one of them

It is easy to assume the EU, with its long annexes, must have a list somewhere. It does not — not for claims.

Annex	What it is	What that means for a claim
Annex II	Prohibited substances	A list of what cannot go in at all
Annex III	Restricted substances	Conditions, not a permitted list
Annex IV	Colorants — permitted list	A colorant not listed cannot be used
Annex V	Preservatives — permitted list	Same
Annex VI	UV filters — permitted list	Same
For a claim	No annex	Evidence under Reg. 655/2013 instead of a list

Article 14 is a list of prohibitions. Three of them work as permitted lists, because a colorant, a preservative or a UV filter that is not in its annex cannot be used. There is no fourth annex for “soothing” or “for sensitive skin”. Under Regulation (EC) No 655/2013 a claim has to rest on «adequate and verifiable evidence» instead, and the method is left to «state of the art practices».

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So the studies have to do it

That is the whole argument for reading the trials themselves. Here are the five, with the size, the length and the design next to each.

Ingredient	People	Length	Design	Measured	Number
Ceramide	50	4 weeks	Single arm, no control	Hydration, TEWL	Hydration median 50 to 80
Panthenol	25 enrolled 21 finished	26 days	Randomised, double-blind, placebo-controlled	Hydration after irritation	Better on the active side in 11, placebo in 1
Colloidal oatmeal	29 women	Not reported	Investigator-blinded	Dryness, scaling, roughness, itch	All four improved
Licochalcone A	1,221	4 weeks	Open study, no control	Redness and related scores	P<0.001
Niacinamide	50 women 46 finished	4 weeks	One forearm untreated, investigator-blind	TEWL, capacitance	TEWL 2.5 vs 3.9

The last row is worth a pause. Niacinamide sits on Korea’s brightening list at 2–5%. This study measured something else entirely — barrier. The ingredient name does not tell you what was measured.

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And where each one is weak

Ingredient	Where it is weak	How to read it
Ceramide	No control group, one site, manufacturer-funded	Read what was measured, not the size of the change
Panthenol	Only one endpoint reached significance	The design is the strongest of the five
Colloidal oatmeal	The abstract does not give the duration	Read it without knowing how long
Licochalcone A	No control, and the product also contained trans-4-t-butylcyclohexanol	The two cannot be separated here
Niacinamide	The facial figures were not tested statistically	Read the forearm numbers

Of the five, one design is clearly the strongest, and it is the smallest study. Twenty-five people, randomised, double-blind, placebo-controlled, with the irritation deliberately induced. The study with 1,221 people has no control group at all. Size and strength are not the same thing, and a box never prints either.

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Four things to check on the box

✔ Look past “for sensitive skin” and check whether the five names are in the ingredient list

✔ The earlier a name sits in that list, the more of it is in there

✔ Photograph the names after “fragrance” so you can compare them later

✔ Try anything new on the inside of your arm for a few days first

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One line

No regulator in these three places names an ingredient for sensitive skin, so the studies have to. Decide first whether your issue is barrier, itch or redness, and five becomes three.

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What I left out, and why

✔ Centella asiatica and madecassoside — I could not open a human study, only reviews

✔ “Fragrance-free is safer” — no primary source for it

✔ The facial figures in the niacinamide study — cheek TEWL fell, but those values were not tested statistically

✔ Prescription drugs and procedures — they do not belong in a cosmetics piece

✔ An EU rule specific to sensitive skin — I did not find one, which is not the same as saying none exists

About the author · Dr. J

MS in Veterinary Medicine, PhD in Life Sciences. I worked as a researcher at the Korea Research Institute of Bioscience and Biotechnology (KRIBB) and now run Beaurea, a cosmetics manufacturing company, where I write the formulas myself. This blog reads the research papers and the regulatory documents and turns them into plain-language criteria for choosing ingredients. I don’t recommend specific products here – only criteria that apply to any product.

📌 Previously

📌 Niacinamide: How Much Is Enough — the same ingredient, seen from the brightening side

📌 Ceramides – cholesterol and fatty acid ratio — the first ingredient here, in full

📌 Panthenol for Skin: What the Dexpanthenol Studies Show — the irritation side

📌 How to Read a Korean Cosmetic Ingredient List — where to find these names on the box

📄 References

· Regulation on Review of Functional Cosmetics, Annex 4 (Korean Law Service, opened 2026-10-17)

· MFDS, Guideline on Test Methods for Substantiating Cosmetic Claims (2018-03, 안내서-0353-02)

· MFDS, Guideline on Cosmetic Labelling and Advertising (2025-08-14, 안내서-0086-07), Annex 2

· Draelos ZD, Raymond I. J Clin Aesthet Dermatol 2018;11(5):30-32

· Biro K, Thaçi D, Ochsendorf FR, Kaufmann R, Boehncke WH. Contact Dermatitis 2003;49(2):80-84

· Reynertson KA et al. J Drugs Dermatol 2015;14(1):43-48 · Jovanovic Z et al. ibid. 2017;16(6):605-611

· Draelos ZD, Ertel K, Berge C. Cutis 2005;76:135-141

· U.S. FDA, “Hypoallergenic Cosmetics” (content current as of 2022-02-25)

· Regulation (EC) No 1223/2009, Article 14 · Regulation (EC) No 655/2013

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This article summarises published studies and public regulatory documents. It is information, not diagnosis or treatment. Of the five studies, two had no control group and one does not report its duration, and one was run on a product containing two actives. Those limits are set out in the tables above rather than hidden. Ingredient names and concentrations are given as criteria for choosing a product, not as a recommendation of any particular one.

— Dr. J Ingredient Notes

October 17, 2026

Can a Moisturizer Slow Skin Aging? What Two Human Studies Measured, and Where Korea’s Wrinkle Rule Draws the Line (Autumn Guide 3)

Cover image for an article asking whether a moisturizer can slow skin aging. It notes a 20-person study measured in a 70 percent humidity room and then a 40 percent humidity room for 30 minutes each, three 28-day moisturizer arms of 42 people, and the four wrinkle actives Korea lists by name. Dr. J Ingredient Notes, Autumn Guide 3.

🇰🇷 한국어판: 피부 노화, 보습크림으로 늦출 수 있을까 – 연구가 잰 자리와 고시가 정한 자리

Hello, this is Dr. J. Today: can a moisturizer slow skin aging? I want to answer it the way the sources actually do — by separating what the studies measured from what the regulation permits you to say.

Start with one finding. Thirty minutes in a drier room was enough to increase fine wrinkles around the eye. Nobody applied anything. Nobody aged. Only the air changed.

That single result tells you where a moisturizer’s job begins. And Korea’s rulebook tells you where it stops — because here, the phrase “helps improve wrinkles” is not a marketing decision. It is a list of four ingredients with concentrations attached.

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Read the sources first

📄 Tsukahara et al. 2007 — 20 people, a 70% room and a 40% room

📄 Stettler et al. 2021 — 42 people per arm, 28 days (open access)

📄 MFDS, Functional Cosmetics Review Regulation, Annex 4 — the four wrinkle actives

📄 FDA — Is It a Cosmetic, a Drug, or Both? — how intended use decides

Annex 4 was opened again today, and the four ingredients, their concentrations, the permitted dosage forms and the efficacy sentence were all read from the original.

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The five-line version

✓ Moving from a 70% to a 40% humidity room for 30 minutes lowered moisture and elasticity and raised fine wrinkles

✓ A moisturizer used once a day for 28 days raised stratum corneum moisture by 38.1 to 72.4%

✓ Neither study reports a wrinkle-correction figure — that number simply is not there

✓ In Korea, four actives are notified by name and concentration for the wrinkle claim

✓ Glycerin, hyaluronic acid, ceramides and panthenol are not on that list

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The two studies, side by side

This article rests on two human studies. Their designs are deliberately different — one changed the air for half an hour, the other applied a cream for four weeks.

Study	Who, and where measured	Conditions	What was measured
Tsukahara et al. 2007 Skin Res Technol	20 people eyelid	30 min in a 70% humidity room, then 30 min at 40%	Conductance (moisture), elasticity, fine wrinkles
Stettler et al. 2021 Cosmetics	42 people in each of three arms forearm	Three creams differing in lipid content, once a day for 28 days	Stratum corneum moisture, user-rated elasticity

One asks how fast the environment moves the skin. The other asks how much of that a cream puts back. The questions are halves of the same question, which is why they sit together here.

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Thirty minutes, two rooms

Twenty people had moisture, elasticity and fine wrinkles measured on the eyelid. Once after 30 minutes of adaptation in a room at 70% relative humidity, and again after 30 minutes at 40% (Tsukahara et al., Skin Res Technol 2007).

✓ Moisture fell at the lower humidity

✓ Elasticity fell as well

✓ Fine wrinkles increased — all three differences were statistically significant

The authors put it plainly: a 30-point difference in humidity changes the properties of the skin within 30 minutes. Same people, same products, different air.

So these wrinkles belong to the reversible side of the ledger. They are not the same thing as the lines that deepen over decades, and it is worth keeping the two apart when you judge a cream.

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Twenty-eight days with a moisturizer

Three creams containing panthenol were made with different lipid contents. 42 people used each one, once a day, for 28 days (Stettler et al., Cosmetics 2021).

✓ Stratum corneum moisture rose +63.9%, +72.4% and +38.1% from baseline

✓ Users who judged elasticity improved: 64.3%, 78.6% and 80.5%

✓ The untreated opposite forearm did not move

That last line carries weight. It rules out season, room conditions and measurement drift — the numbers moved on the treated side.

One caution: the elasticity figures are what users reported, not an instrument reading. They should not be stacked on top of the moisture numbers as if they were the same kind of evidence.

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Where the numbers stop

Lay the two studies out by measure, and the sentence “moisturizer reduces wrinkles” shows you exactly where it breaks.

Measure	Tsukahara 2007	Stettler 2021	Is there a number?
Moisture	Fell significantly at lower humidity	+38.1% to +72.4% from baseline	Yes, in both
Elasticity	Fell significantly at lower humidity	64.3 / 78.6 / 80.5% of users saw improvement	Yes, in both
Fine wrinkles	Increased significantly at lower humidity	—	Yes, in one
Wrinkle depth or correction	—	—	No. Neither study reports it

The last row is the point of this article. There is no wrinkle-correction figure in either study. What exists is moisture, elasticity, and fine wrinkles under dry air.

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Korea names four actives

Annex 4 of the MFDS Functional Cosmetics Review Regulation lists the ingredients that may carry the wrinkle claim. There are four, and each comes with a concentration.

No.	Ingredient	Concentration
1	Retinol	2,500 IU/g
2	Retinyl palmitate	10,000 IU/g
3	Adenosine	0.04%
4	Polyethoxylated retinamide	0.05 – 0.2%

Permitted dosage forms are lotions, solutions, creams and sheet masks. The efficacy sentence is fixed: 「피부의 주름개선에 도움을 준다」 — helps improve skin wrinkles. Directions are prescribed too, down to removing a sheet mask after 10 to 20 minutes.

Reading the annex again today, glycerin, hyaluronic acid, ceramides and panthenol appear nowhere in it. That is not a verdict on those ingredients. It means they are not on the road that leads to this particular sentence.

※ Note the annex’s own title: “types of functional cosmetics for which data submission is waived.” The listed concentration is not a ceiling. It is the amount at which you need not file fresh efficacy data.

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Korea and the United States decide this differently

This is the part that travels badly across borders. The same jar of cream can be described in two quite different ways depending on where it is sold.

	Korea	United States
What fixes the wording	A government notification lists four actives with set concentrations. Use one at that level and the efficacy sentence is prescribed	Intended use decides the category. There is no list of approved anti-wrinkle actives
The sentence on the box	「피부의 주름개선에 도움을 준다」 — helps improve skin wrinkles	No prescribed sentence. Wording is the company’s to choose, and to defend
Where it can go wrong	Using the phrase without the notified active and the review or report behind it	A claim to treat wrinkles or to affect the skin’s structure or function can make the product a drug under the FD&C Act
What the shopper sees	The box prints 기능성화장품 (functional cosmetic) and the efficacy sentence under it	Nothing on pack marks the category

In the United States, the FD&C Act defines a cosmetic by what it does to appearance, and a drug by intent to affect the structure or any function of the body. The FDA’s own guidance says the category follows intended use — so a claim to treat wrinkles, rather than to make them look softer, can move a product into drug territory.

Korea took the other road. It fixed a short list of actives, attached concentrations, and prescribed the sentence. The upside for a shopper is unusual: you can read the claim off the box and know exactly what was reviewed.

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Reading the numbers carefully

✓ The 30-minute study is about air, not about cream — it shows how quickly dry air moves the skin, not what a product does

✓ The 28-day percentages are change from baseline — the drier the starting skin, the larger the possible rise. They do not compare products

✓ Elasticity there is a user rating — a questionnaire result, not an instrument reading

Hold those three in mind and the same figures read differently. What was measured, in whom, under what conditions is the habit worth building.

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What I left out, and why

✓ “Moisturizer smooths wrinkles” — Stettler measured moisture and elasticity. There is no wrinkle figure, so none is quoted here

✓ Mechanism of aging (inflammation, glycation and so on) — the primary sources I could open were reviews, so that passage is absent

✓ A list of five moisturizing ingredients — covered in the first autumn guide; linked below instead

✓ Comparisons with procedures or prescription products — out of scope for a cosmetics article

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So where does a moisturizer land

✓ Fine lines that come from dryness — this is the moisturizer’s ground, and the 30-minute study is the evidence for it

✓ The phrase “helps improve wrinkles” — this belongs to a functional cosmetic built on one of the four actives

✓ They are not rivals — moisturizer daily, notified active at its stated concentration

Putting cream on every day is maintenance against what the environment takes away. Small, but the 30-minute result shows how quickly that ground shifts.

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What to check on the box

✓ In Korea, whether 기능성화장품 and the wrinkle sentence appear together

✓ Which of the four actives it is, and whether the concentration is printed

✓ For the moisturizing side, whether glycerin sits high in the ingredient list, and whether ceramides come with cholesterol and fatty acids

✓ Indoor humidity — 30 minutes is enough to change things. Keep out of the direct path of a heater

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One line

A moisturizer’s reach is the fine lines that dryness creates. “Wrinkle improvement” is the work of four notified actives — and the two go together rather than against each other.

Next: custom-blended cosmetics — what the product mixed for you at the counter actually is (Ingredient Guide 22).

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📌 Previous guides

📌 Panthenol for Skin: What the Dexpanthenol Studies Show (Guide 7) — the 28-day trial in full

📌 Adenosine 0.04%: Who Decided That Number (Guide 12) — one of the four, on its own

📌 Retinol: Start at 0.1% (Guide 1)

📌 Ceramides: Cholesterol and Fatty Acid Ratio (Guide 4)

📌 Hyaluronic Acid: How to Read the Molecular Weight (Guide 6)

About the author · Dr. J

📄 References

· Tsukahara K et al., Skin Res Technol 2007;13(2):184-188

· Stettler H et al., Cosmetics 2021;8(1):18

· Ministry of Food and Drug Safety, Regulation on the Review of Functional Cosmetics, Annex 4

· U.S. FDA, “Is It a Cosmetic, a Drug, or Both? (Or Is It Soap?)”, page updated 11 September 2024

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This article summarises published research and regulatory documents. It is not a diagnosis or a treatment, and it does not recommend a particular product. Figures are quoted as the sources report them; different conditions give different numbers. If a skin concern worries you, please speak to a professional.

— Dr. J Ingredient Notes

October 3, 2026

Moisturizing Ingredients for Dry Skin: What the Research Shows for Five of Them (Autumn Guide)

Cover image for a Dr. J Ingredient Notes autumn guide on moisturizing ingredients for dry skin. Five ingredients with human studies: glycerin, urea, ceramides, panthenol and hyaluronic acid, with what each number was compared with.

🇰🇷 한국어판: 건조한 피부 보습 성분 TOP5 – 가을에 고르는 기준

Hello, I’m Dr. J. Autumn is when the same question arrives every year: which moisturizing ingredients actually do something for dry skin? Here are five, each with a human study attached, and each with the numbers read the way I would read them in the lab.

This is not a ranking. The five do different jobs, and the one you want depends on what your skin does after cleansing: tightness, roughness and flaking, or stinging. Match that first and the shelf gets much smaller.

Below: one table with all five studies side by side, then each ingredient in turn, then the part most ingredient articles skip — what each number was compared with, because “improved by 72%” and “better than placebo” are not the same claim. At the end, how Korean regulation treats these five, and why squalane is not among them.

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📄 If you’d rather read the primary sources

📄 Lodén et al. 2002 — glycerin 20% and urea 4% creams, 197 patients, 30 days (Acta Derm Venereol)

📄 Spada et al. 2021 — ceramide-dominant cream and cleanser, 28-day randomized trial (Dermatol Ther)

📄 Stettler et al. 2021 — panthenol emollients, three 28-day studies (open access)

📄 Pavicic et al. 2011 — hyaluronic acid 0.1%, 76 women, 60 days (PubMed)

📄 Korea — Cosmetic Safety Standards, Annex 2: ingredients with use limits (Korean)

The Stettler paper is fully open, tables included. The Korean annex downloads as the original table.

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The short version

✔ Tight skin — humectants that hold water: glycerin, hyaluronic acid

✔ Rough, flaking skin — urea, capped at 10% in cosmetics sold in Korea

✔ Stinging after cleansing — barrier ingredients: ceramides, panthenol

✔ All five have human studies of one to two months

✔ Before trusting a percentage, ask what it was compared with (Table 2)

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All five studies in one table

Ingredient	Study	People · duration	Compared with	What was measured
Glycerin 20%	Lodén et al. 2002	68 of 197 · 30 days	the same cream without glycerin	dryness improved in 85% (placebo 63%)
Urea 4% with 4% sodium chloride	Lodén et al. 2002	63 in the same study · 30 days	the other creams in that study	improved in 89%; smarting in 24%
Ceramides	Spada et al. 2021	100 adults (83 completed) · 28 days	a comparator regimen · double-blind	water loss P=.0342; hydration P<.0001
Panthenol	Stettler et al. 2021	42 people × 3 studies · 28 days	the untreated opposite arm	hydration +38.1% to +72.4% vs baseline
Hyaluronic acid 0.1%	Pavicic et al. 2011	76 women · 60 days	placebo	all five molecular weights improved hydration

Read the “compared with” column first. It is the column that decides how much weight each number can carry, and it is the one marketing copy leaves out.

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1 and 2. Glycerin and urea — measured in the same study

In this trial, 197 patients with atopic dermatitis used one of three creams at least once a day for 30 days (Lodén et al., Acta Derm Venereol 2002):

✔ a cream with 20% glycerin — 68 people

✔ the same cream base without glycerin, as placebo — 66 people

✔ a cream with 4% urea and 4% sodium chloride — 63 people

After 30 days, dermatologist-assessed dryness had improved in 85% of the glycerin group, 63% of the placebo group and 89% of the urea group. Taking the patients’ own assessments together with the dermatologist’s, the paper’s conclusion is that the glycerin cream and the urea-saline cream had equal effects on dryness.

What separated them was how they felt. Smarting — that brief sting on application — was rated severe or moderate by 10% of people on the glycerin cream and 24% on the urea-saline cream (p<0.0006). For stinging, itching and dryness/irritation as separate reactions, the paper reports no differences.

That is why I treat urea as an ingredient to choose on calm days, and why it earns its place on heels, elbows and anywhere the skin is genuinely thickened rather than simply dry.

※ The participants had atopic dermatitis. I am quoting the dryness and sensory results, not treating this as a treatment claim. The creams were supplied by the manufacturer (Aco Hud AB).

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3. Ceramides — the barrier numbers move first

A ceramide-dominant cream used together with a matching cleanser for 28 days, in a randomized, double-blind trial of 100 adults with moderate eczema, 83 of whom completed it (Spada et al., Dermatol Ther 2021).

✔ Transepidermal water loss fell compared with the comparator (P=.0342)

✔ Stratum corneum hydration rose compared with the comparator (P<.0001)

✔ Eczema severity (EASI) showed no difference between the groups (P=.7804)

✔ Satisfaction with itch, dryness and smoothness was higher on the ceramide regimen

The third line is the honest one, and it is why I like this study. The barrier measurements moved; the disease score did not. A moisturizer is a moisturizer. Ceramides also work as part of a set — with cholesterol and fatty acids — which is the subject of the ceramide guide linked at the end.

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4. Panthenol — once a day, 28 days

Three parallel studies of panthenol-containing emollients that differed in lipid content: low, intermediate and high. Each had 42 participants applying the product to one forearm once daily for 28 days, leaving the other forearm untreated (Stettler et al., Cosmetics 2021).

At day 28, hydration had risen from baseline by 63.9% (low lipid), 72.4% (intermediate) and 38.1% (high). On the untreated arm, hydration did not move — which is what makes the rise hard to attribute to the weather.

Two caveats travel with those percentages: they are measured against baseline, not against a panthenol-free cream, and they belong to the whole formulation, which also contained lipids such as shea butter and squalane. The full reading of this study is in the panthenol guide.

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5. Hyaluronic acid — five molecular weights in one study

Creams with 0.1% hyaluronic acid at five different molecular weights, used by 76 women for 60 days against placebo (Pavicic et al., J Drugs Dermatol 2011). All five improved hydration relative to placebo.

So on a label, what I look for is more than one molecular weight listed, rather than a single impressive-sounding number. How to read those numbers is covered in the hyaluronic acid guide.

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How to read the numbers — the comparator decides the meaning

The five studies did not use the same yardstick. Here is what each comparison can and cannot tell you.

Comparator	Used here by	How to read the number
The same cream minus one ingredient	glycerin	The closest thing to what that ingredient added
A different product	ceramides	A product-versus-product result, not one ingredient
Untreated skin	panthenol	The whole cream versus applying nothing
Day 0 (baseline)	the panthenol percentages	Season and humidity ride along; check whether untreated skin was measured too
Placebo	hyaluronic acid	Same formula, different ingredient

The strongest design here is the same cream with one ingredient removed: formulation held constant, so the difference is attributable to the ingredient. The weakest, in this sense, is a percentage against baseline, because the season is inside that number — unless, as in the panthenol studies, untreated skin was measured alongside and stayed flat.

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How Korea regulates these five

One of the five appears in Annex 2 of the Cosmetic Safety Standards — the list of ingredients with use limits.

	Korea	What that means on a label
Urea	listed in Annex 2 of the Cosmetic Safety Standards at 10% (CAS 57-13-6)	A product sold in Korea stays at or below 10%
Glycerin · ceramides · panthenol · hyaluronic acid	not in that annex	No ceiling, and no minimum either — concentration varies by product
Brightening · anti-wrinkle ingredients	listed with set amounts in Annex 4 of the functional-cosmetics review rules	Moisturizing ingredients are not in that kind of table

This is worth knowing when you compare a Korean product with one from elsewhere. Korea sets a ceiling for urea at 10%; the study above used 4%, well inside it. For the other four, there is no number in the regulation at all — no maximum, and equally no minimum, which is why the ingredient list’s order matters more than any claim on the front of the bottle.

It is also why moisturizing ingredients are not “functional cosmetics” in the Korean sense. Brightening and anti-wrinkle ingredients have an annex listing set amounts; hydration does not work that way.

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Why squalane is not on this list

Squalane comes up in every autumn skincare article, so I went looking again. I could not find a study in which squalane was applied to human skin and its hydration effect compared with a placebo. What exists is work outside the body — an ex vivo study of how a squalane-based emulsion carries other compounds into skin, and a cell study of squalane and UV-related collagen effects in fibroblasts.

That is not evidence of absence; it is a statement about what I could verify. If I find a human trial, squalane gets its own guide.

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Five things to check on the label

✔ Glycerin — near the top of the ingredient list; higher means more of it

✔ Urea — if a percentage is printed, 10% or below, and start low

✔ Ceramides — cholesterol and fatty acids listed alongside them

✔ Panthenol — for a cream you will use on stinging days, fragrance low on the list or absent

✔ Hyaluronic acid — more than one molecular weight listed

My own order is simple. If tightness comes first after cleansing, I reach for the water-binding side. If stinging comes first, I reach for the barrier side. If both, one product containing both is a reasonable place to start.

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In one line

Tight skin: glycerin and hyaluronic acid. Rough skin: urea. Stinging skin: ceramides and panthenol. Start from what your skin does, and read every percentage together with what it was compared against.

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📌 Earlier guides

📌 Ceramides – the cholesterol and fatty acid ratio (Ingredient Guide 4)

📌 Panthenol for Skin: What the Dexpanthenol Studies Show (Ingredient Guide 7)

📌 Hyaluronic Acid: How to Read the Molecular Weight (Ingredient Guide 6)

📌 How to Read a Korean Cosmetic Ingredient List — Where the Order Stops at 1% (Ingredient Guide 14)

About the author · Dr. J

📄 References

· Lodén M, Andersson AC, Anderson C, et al. Acta Derm Venereol 2002;82(1):45-47

· Spada F, Harrison IP, Barnes TM, et al. Dermatol Ther 2021;34(4):e14970

· Stettler H, de Salvo R, Olsavszky R, et al. Cosmetics 2021;8(1):18

· Pavicic T, Gauglitz GG, Lersch P, et al. J Drugs Dermatol 2011;10(9):990-1000

· Korea MFDS — Regulation on Safety Standards for Cosmetics, Annex 2 (ingredients with use limits)

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This article summarises published research and safety assessments. It is information, not a diagnosis or a treatment plan. If something about your skin worries you, please talk to a professional.

— Dr. J Ingredient Notes

September 23, 2026

Panthenol for Skin: What the Dexpanthenol Studies Show (Ingredient Guide 7)

Cover image for a Dr. J Ingredient Notes guide on panthenol, ingredient guide 7. What the research shows about panthenol for skin: a dexpanthenol cream tested against the same cream without it on irritated skin, and three 28-day studies of panthenol moisturisers on very dry skin with 42 people each.

🇰🇷 한국어판: 판테놀 효능, 숫자로 확인된 것 (성분 백과 ⑦)

Hello, I’m Dr. J. Today’s question is a simple one: what does panthenol actually do for skin, and how much of that has been measured in people? This is Ingredient Guide 7.

Panthenol turns up on the back of almost every soothing cream, barrier cream and “recovery” product, and in plenty of shampoos too. It is usually described in a word or two – soothing, hydrating, vitamin B5 – and rarely with a number attached. So here is the first surprise: panthenol isn’t the thing that does the work. Skin converts it into something else first.

Below I put two human studies side by side. One tested a dexpanthenol cream on deliberately irritated skin against the same cream without dexpanthenol. The other ran three 28-day studies of panthenol-containing moisturisers on very dry skin, 42 people each. At the end is the conclusion of the US Cosmetic Ingredient Review panel on panthenol’s safety – and a short list of claims I left out, with the reason for each.

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📄 If you’d rather read the primary sources

📄 Proksch & Nissen 2002 — irritated skin, dexpanthenol cream vs vehicle

📄 Stettler et al. 2021 — three 28-day studies, 42 people each (open access)

📄 Cosmetic Ingredient Review 2022 — safety assessment of panthenol and derivatives

The Stettler paper is open access, including the per-product tables and the measurement methods. The Proksch paper’s abstract is public.

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The short version

✔ Panthenol and dexpanthenol are names for the same family; in skin, dexpanthenol becomes pantothenic acid (vitamin B5)

✔ On irritated skin, a dexpanthenol cream applied twice a day repaired the barrier faster than the same cream without it

✔ In three 28-day studies on very dry skin (42 people each), skin hydration rose 38.1% to 72.4% from baseline

✔ In the same studies, hydration on the untreated arm did not move

✔ The US Cosmetic Ingredient Review panel concluded panthenol is safe as currently used in cosmetics

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Panthenol vs dexpanthenol – why two names

Ingredient lists say panthenol; studies and pharmacy ointments usually say dexpanthenol. Panthenol exists in two mirror-image forms, and the one skin converts to pantothenic acid is the D-form – dexpanthenol. That conversion is why you’ll also see it called provitamin B5.

Why does that matter? Pantothenic acid is a building block of coenzyme A. As the Proksch & Nissen abstract explains, coenzyme A catalyses the early steps in making fatty acids and sphingolipids – lipids that are essential to the layered lipid structure of the stratum corneum and to cell membranes. That is the biological reason people expected panthenol to help a damaged barrier. The studies below are where that expectation was tested.

Inside the bottle, panthenol has more than one job. The Cosmetic Ingredient Review report lists it as a hair-conditioning agent, a skin-conditioning agent (humectant) and a solvent. That is why the same name appears on both a conditioner and a face cream.

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On irritated skin – dexpanthenol cream vs the same cream without it

In this study, skin was deliberately irritated with sodium lauryl sulphate (SLS), a cleansing agent, applied in patch-test chambers. The irritated sites were then treated twice a day with either a dexpanthenol cream or the identical cream without dexpanthenol (the vehicle), and some sites were left untreated. Barrier repair, hydration, roughness and redness were measured with instruments rather than judged by eye (Proksch & Nissen, J Dermatolog Treat 2002).

✔ Barrier repair — significantly faster with dexpanthenol than with the vehicle or with no treatment

✔ Stratum corneum hydration — rose with both creams, but significantly more with dexpanthenol

✔ Roughness — fell with both creams, with dexpanthenol again ahead

✔ Redness — significantly reduced with dexpanthenol; the vehicle had no effect

The weight of this study comes from the comparison. Any cream will add some water and oil to the skin; by testing against the same base without dexpanthenol, the study isolates what dexpanthenol itself added. On all four measures, it added something.

※ The abstract does not give the number of participants, the length of the study or the dexpanthenol concentration. A later review article quotes figures for this trial, but I couldn’t confirm them in the original, so I have left them out.

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On very dry skin – three studies, 42 people each, 28 days

The second paper reports three parallel studies of panthenol-containing emollients that differed in how much lipid (oil) they contained: low, intermediate and high (Stettler et al., Cosmetics 2021). Participants were 18 to 70 years old and had skin that a dermatologist judged to be very dry, flaky and sensitive. Each person applied the product to one forearm once a day, about 2 mg per square centimetre, and left the other forearm untreated. Which arm got the product was decided at random.

	Emollient 1 lowest lipid	Emollient 2 intermediate lipid	Emollient 3 highest lipid
Participants	42 · mean age 59	42 · mean age 58	42 · mean age 57
Skin hydration day 28 vs baseline	+63.9%	+72.4%	+38.1%
Water loss (TEWL) day 28 vs baseline	−11.0% (significant)	−5.7% (not significant)	lower, not significant
Stratum corneum lipids	cholesterol +9.8% · free fatty acids +3.7%	no change	cholesterol +12.5% · free fatty acids +26.3%

Three things stand out. First, hydration rose clearly with all three products. Second, on the untreated arm, hydration stayed flat – the paper reports it holding at about the same capacitance reading throughout. That makes it hard to put the rise down to the weather or to people getting used to the measurements. Third, only Emollient 1 significantly reduced water loss (TEWL); the other two moved in the right direction without reaching significance.

So how much of this is panthenol? That’s the honest limit of this paper. The results belong to each cream as a whole: all three also contained lipids such as shea butter and squalane, and the paper does not state the panthenol concentration. The comparison was against untreated skin, not a panthenol-free cream. The study was also open-label – everyone knew what they were applying – and the products were supplied by the manufacturer. None of that makes the numbers wrong, but it tells you what kind of numbers they are.

The intermediate-lipid product gave the largest hydration gain, while the highest-lipid product gave the smallest – a reminder that a richer cream is not automatically a more hydrating one. On tolerability, the paper reports no local or systemic adverse events related to the products over the 28 days.

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The two studies side by side

	Proksch & Nissen 2002	Stettler et al. 2021
Skin	deliberately irritated with sodium lauryl sulphate (SLS)	very dry, flaky and sensitive, as judged by a dermatologist
Compared with	the same cream without dexpanthenol (vehicle), and untreated skin	the untreated opposite forearm
How often	twice a day	once a day, about 2 mg/cm²
Design	vehicle-controlled (numbers of people and days not given in the abstract)	randomised as to which arm was treated · open-label · three studies × 42 people · 28 days
Key result	faster barrier repair, more hydration, less roughness, less redness than vehicle	hydration +38.1% to +72.4%; untreated side flat

Each study fills the other’s gap. The 2002 trial has the right comparison – dexpanthenol against its own vehicle – but its abstract gives no numbers. The 2021 studies have clear numbers, but they describe whole products compared with untreated skin. Put together, they support a modest, specific statement: panthenol has human evidence on two fronts, recovery after irritation and hydration of very dry skin.

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Safety – what the Cosmetic Ingredient Review panel concluded

In the US, the Cosmetic Ingredient Review (CIR) expert panel assesses the safety of cosmetic ingredients. In 2022 it reviewed panthenol, pantothenic acid and five derivatives together. Its conclusion is one sentence: all seven are safe in cosmetics in the present practices of use and concentration described in the assessment.

It helps to keep the two questions apart. The CIR conclusion answers “is it safe to use the way it is used now?” – not “how well does it work?”. For the second question, look to the two studies above.

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How I use it

✔ When exfoliating acids or retinol leave my skin stinging, I switch to a panthenol-containing cream for a few days

✔ I apply it while skin is still slightly damp after cleansing, and on dry days add a cream on top

✔ For very dry skin I give it 28 days before judging – the length of the Stettler studies

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What I left out, and why

✔ Participant numbers, duration and concentration for the 2002 trial — quoted in a review, but not in the original abstract I could read

✔ Wound and burn claims — in a cosmetics article they read like drug claims

✔ “Choose at least X%” — I found no original study comparing panthenol concentrations head-to-head on human skin

✔ Pairing rules with other ingredients — I found no primary study testing panthenol in specific combinations

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Three things to check when you buy

✔ Where panthenol sits in the ingredient list — higher up means more of it (see the ingredient-list guide below)

✔ Texture — in the 28-day studies, the intermediate-lipid product gave the largest hydration gain

✔ Where fragrance sits — if this is the cream for your irritated days, you want fragrance low on the list or absent

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In one line

Panthenol is converted in skin to vitamin B5, and it has human evidence for recovery after irritation and for hydrating very dry skin. When you read a number, check first what it was compared with.

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📌 Earlier guides

📌 Ceramides – the cholesterol and fatty acid ratio (Ingredient Guide 4)

📌 Hyaluronic Acid: How to Read the Molecular Weight (Ingredient Guide 6)

📌 Retinol: Start at 0.1% (Ingredient Guide 1)

📌 How to Read a Korean Cosmetic Ingredient List — Where the Order Stops at 1% (Ingredient Guide 14)

About the author · Dr. J

📄 References

· Proksch E, Nissen HP. Dexpanthenol enhances skin barrier repair and reduces inflammation after sodium lauryl sulphate-induced irritation. J Dermatolog Treat 2002;13(4):173-178

· Stettler H, de Salvo R, Olsavszky R, et al. Cosmetics 2021;8(1):18

· Scott LN, Fiume M, Bergfeld WF, et al. Safety Assessment of Panthenol, Pantothenic Acid, and Derivatives as Used in Cosmetics. Int J Toxicol 2022;41(3 Suppl):77-128

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This article summarises published research and safety assessments. It is information, not a diagnosis or a treatment plan. If something about your skin worries you, please talk to a professional.

— Dr. J Ingredient Notes

September 22, 2026