Guide overview
Start with the shared principles
Glycolic, Lactic and Mandelic Acid are all AHAs, but they are not aliases. Structure, percentage, pH, vehicle, contact time and product format determine real use, so one number or a gentle label cannot rank every finished formula.
Three separate materials
Each acid has a defined INCI. AHA and fruit acid belong in discovery rather than exact checker identity. Changing from one acid to another is a new product introduction.
Study-format limits
Lactic Acid has specified topical finished-formula evidence, while Glycolic and Mandelic Acid literature often includes professional peels, acne contexts or multi-active products. These sources do not create a universal home-percentage ranking or authorize supervised procedures at home.
Gentle is not a guarantee
Molecular-size and feel claims are often used to market Mandelic and Lactic Acid, but the complete formula can still sting. A rinse-off cleanser, leave-on serum and professional peel do not share one exposure schedule.
Choosing a first acid
Choose one product by exact INCI, format, existing routine and tolerable texture. Start one evening weekly without Retinol, Retinal, Salicylic Acid or another AHA that night.
When to reduce or stop
Check delayed dryness on the next day and day three. Stop for persistent burning, marked redness, cracking or widespread peeling. A lack of stinging does not justify an immediate frequency increase, and broad-spectrum sunscreen remains daily.
References
Sources
- Peer reviewedGlycolic acid peel therapy – a current review
Clinical, Cosmetic and Investigational Dermatology
- Peer reviewedEpidermal and dermal effects of topical lactic acid
Journal of the American Academy of Dermatology
- Peer reviewedComparative study of efficacy and safety of 45% mandelic acid versus 30% salicylic acid peels in mild-to-moderate acne vulgaris
Journal of Cosmetic Dermatology