Ingredient Beauty BenefitsAntioxidant · Thioctic Acid
Alpha-lipoic acid: 50.8% on the treated side, 40.7% on the placebo side
One trial: 33 people applied a 5% cream to one half of the face and its vehicle to the other for 12 weeks. Laser profilometry showed roughness falling 50.8% versus 40.7%, a significant difference (P < .001). The 40.7% on the placebo side has to be read alongside it.
Last checked Sep 20, 2026
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- What it is
A substance the body uses in making energy. In cosmetics it is often noted for dissolving to some degree in both water and oil.
- What it is used for
Products marketed for wrinkles and skin texture. It is also sold as an oral supplement.
- How it is said to work
It is described as an antioxidant that also damps inflammation.
There are no numbers and no citations in this box. What has been established, and how far, is below.
At a glance
- In pregnancy
- Not established
- Irritation
- Moderate
- Daytime use
- ✓ Fine
- How well established
- Moderate evidence
- Concentration studied
- 5%
- Length of the studies
- 12 weeks
Not a measurement — reported irritation grouped into five steps. It varies between people.
“Concentration studied” and “Length of the studies” are taken straight from the research on this page. They are not a recommended dose, and the figure for each finding is written out in the text.
This is not how large the effect is but how well confirmed it is. It shows the highest grade among the findings on this page.
Alpha-lipoic acid takes part in how the body makes energy. It has long been discussed as an antioxidant and is also sold as an oral supplement.
For the topical form we found one randomised, placebo-controlled, double-blind trial. It was run at the Karolinska in Sweden in 2003, and the design is unusually well formed for this layer: the two sides of the same face were compared, and the control was the same cream with only this ingredient removed.
But the most important number in that trial is not on the treated side — it is on the placebo side. It is below.
Contents
What is established
The same ingredient at a different strength, in a different formula, is a different product. These are the conditions the studies used.
Roughness fell 50.8% — and 40.7% on the placebo side
This is the 2003 Karolinska trial. 33 women, mean age 54.4, took part. After randomisation, one half of the face received 5% alpha-lipoic acid cream and the other the same cream with only this ingredient removed, twice daily for 12 weeks, double-blind.
Four methods of assessment were used: self-evaluation, clinical evaluation, photographic evaluation, and laser profilometry. The last is the most objective of them, measured at the start and at the end.
All four showed a statistically significant improvement on the alpha-lipoic acid side.
Profilometry:
- Alpha-lipoic acid side: roughness down 50.8% (44.9–54.0)
- Placebo side: roughness down 40.7% (32.4–48.7)
- P < .001
Do not stop reading there. The placebo side improved by 40.7%. That is the result of applying a cream without the ingredient twice a day for twelve weeks.
What alpha-lipoic acid added is roughly 10 percentage points on top. That is clear statistically; whether you could tell that difference in a mirror is another question.
And it is one trial. A single study of 33 people cannot rule out chance. The same design needs repeating elsewhere.
- Randomised controlled trial in people · 33 participants · 12 weeks · Compared with vehicle (same formula minus the active) · Funding not declared · Endpoint instrument measurement PMID 14616378
This ingredient is not among Korea's four listed wrinkle actives
In Korea, only four ingredients are listed in the functional cosmetics review rule (Annex 4) as accepted for a 'helps improve wrinkles' claim without submitting efficacy data of your own: retinol (2,500 IU/g), retinyl palmitate (10,000 IU/g), adenosine (0.04%) and polyethoxylated retinamide (0.05–0.2%).
Alpha-lipoic acid is not on that list. It does not mean it does not work; it means a product making the claim has to go through individual review.
If wrinkles are the goal, the listed retinol and adenosine are ahead on both the number and the size of their trials.
How to use it
- The trial used 5% cream twice a day for 12 weeks.
- It can sting. Alpha-lipoic acid is among the ingredients where irritation on application is reported. Consider starting every other day.
- Sunscreen has to come with it. What the trial addressed was photoageing, and leaving the cause in place leaves little behind.
- The oral supplement and the topical are different questions. This page covers only the topical.
- If wrinkles are the goal, retinol is a reasonable place to start.
Cautions
- Irritation and stinging are reported. 5% is not a low concentration.
- There is one trial, of 33 people.
- The placebo side improved 40.7%. Read without that figure, the ingredient looks stronger than it is.
- We found no data on use in pregnancy.
- The trial looked no further than 12 weeks.
With a new ingredient, apply a small amount somewhere inconspicuous, such as the inner arm, for two days first. Stop if it reddens or stings.
Related skin concerns
What this article relies on
- PubMed — 미국 국립의학도서관 문헌 데이터베이스National Library of Medicine · Checked on 2026-09-16
- 기능성화장품 심사에 관한 규정 [별표 4] 자료제출이 생략되는 기능성화장품의 종류 — 식품의약품안전처고시 제2025-88호식품의약품안전처 · 시행 2025-12-16 · Checked on 2026-09-16