evidently.
← all ingredients

Lactic Acid (AHA)

LACTIC ACID

The gentler AHA — exfoliates like glycolic while actually improving hydration.

bufferinghumectantskin conditioningCAS 50-21-5

Why it works

A larger AHA molecule that penetrates more slowly (hence gentler), lactic acid exfoliates dead surface cells and doubles as a humectant — it's a component of the skin's own natural moisturizing factor. At 12% it has shown effects reaching into the dermis.

Concentration matters

Studied at 5–12%; the firmness data comes from 12%.

The evidence, by concern

Wrinkles & aging

Good evidence

12% improved firmness and fine wrinkling in controlled testing

How sure are we
good
How much it helps
subtle
Do studies agree
mostly agree

A three-month controlled comparison found 12% lactic acid increased skin firmness and thickness and improved fine lines, while 5% changed only the surface; a separate 22-week vehicle-controlled trial of 8% lactic acid confirmed photoaging improvement versus vehicle.

The receipts

27 trials/reviews indexed · showing most cited

Dryness

Good evidence

Exfoliant and moisturizer in one — well documented

How sure are we
good
How much it helps
modest but real
Do studies agree
strongly agree

As part of the skin's natural moisturizing factor, lactate reliably improves hydration and rough, flaky texture in double-blind trials (classically as 12% ammonium lactate) — the reason it anchors so many body lotions for rough skin.

The receipts

10 trials/reviews indexed · showing most cited

Safety, without the fear

Anchored to regulatory assessments — not hazard lists. Dose makes the poison; these are the conclusions at real-world cosmetic use.

CIR · Cosmetic Ingredient Review

Same CIR conclusion as other AHAs: safe at ≤10% for consumers at pH ≥3.5 (12% products sit at the boundary — expect tingling). Increases sun sensitivity; use sunscreen.

Source →
Spotted an error, or a study we missed? Claims were fact-checked against the cited literature in August 2026; independent clinical sign-off is pending — corrections welcome.