AHA (glycolic / lactic acid)
AHA · alpha hydroxy acids · glycolic acid · lactic acid
Alpha-hydroxy acids for smoother texture, brighter tone and the look of fine lines.
TipoCosmetic (topical)
Il voto risponde a: What does the human evidence support for: Exfoliation, texture & tone?
Grado
B
Moderata
Il voto misura la qualità dell'evidenza, non è un consiglio ad assumere o acquistare.
- Classe
- Skincare / topical
- Uso principale
- Exfoliation, texture & tone
- Forza evidenza
- medium
- Ultima revisione
- 2026-07-01
In sintesi
Well-evidenced cosmetic exfoliants: at sensible strengths they smooth texture and even tone, and lactic acid is the gentler, more hydrating option. Overdoing strength or frequency is where they go wrong.
Cosa dice l'evidenza
AHAs like glycolic and lactic acid have controlled evidence for improving skin texture, tone and the appearance of fine lines and photoaging through exfoliation and, over time, effects in the dermis. Glycolic (smallest molecule) penetrates most and is the most studied; lactic acid is gentler and also humectant. This describes cosmetic exfoliation, not chemical peels performed as medical procedures. As always the ingredient's evidence isn't a specific product's promise — concentration, pH and formulation drive both benefit and irritation. Grade B.
Studi chiave
- [1]
Alpha-hydroxy acids and photoaging / texture · RCT
Improved texture and tone with regular use.
Apri su PubMed ↗ - [2]
- [3]
AHA mechanisms and dermal effects (review) · review
Surface and deeper effects over time.
Apri su PubMed ↗
Meccanismo
Weaken the bonds between surface corneocytes to promote even shedding, smoothing texture and tone; chronic use is associated with increased dermal glycosaminoglycans and collagen in studies.
Sicurezza
Cause dose-dependent stinging, irritation and increased sun sensitivity — daily SPF is important. Start low and infrequent. High-strength professional peels are a separate, clinical matter and out of scope here.
Contesto dosaggio
Leave-on cosmetic products commonly use ~5–10% at a controlled pH; higher strengths and low pH raise both efficacy and irritation. More is not better if it inflames the skin.
Esempi di applicazione
- Used a few evenings a week, per the product's instructions.
- Followed by daily sunscreen, since AHAs raise sun sensitivity.
- Lactic acid for sensitive skin; start low and infrequent.
Nota dal campo
AHAs work — the mistakes are strength and frequency, not the ingredient. We grade them B, favour gentler lactic acid for sensitive skin, and always pair with sunscreen.