Two acids, two characters
Lactic acid and mandelic acid are the two most popular AHAs used in professional cosmetology. They share a mechanism — both exfoliate dead skin cells, speed up cell renewal and improve skin texture. But that's largely where the similarity ends. They differ in molecule size, depth of penetration and what else they do for the skin. That's what determines which one suits you.
Lactic acid
gentle renewal with intensive hydration
- dry, dehydrated, dull skin
- early signs of ageing and fine lines
- sensitive and vascular skin (low concentrations)
- fading sun-related pigmentation
- result: hydration, radiance, even skin tone
Mandelic acid
deeper exfoliation and sebum regulation
- oily, combination, acne-prone skin
- enlarged pores and blackheads
- adult acne and post-acne hyperpigmentation
- tanned skin (higher tolerance)
- result: mattifying, cleansing, sebum control
How to tell which one is right for you
Rather than looking for the "better" acid, it helps to ask: what's my main concern? The mirror check below is a good starting point — the same question a good consultation begins with:
- Skin feels dry, tight, dull or grey — it lacks radiance, and fine lines are more visible by the end of the day → direction: lactic acid.
- Skin looks shiny during the day, pores are visible, and blackheads or breakouts appear from time to time → direction: mandelic acid.
- Combination skin — dry around the cheeks and oily in the T-zone — will likely respond well to a blend of both acids, or alternating sessions.
- Sensitivity and redness — both acids can be used on sensitive skin, but lactic acid is usually the first choice. Mandelic acid, at lower concentrations, is sometimes surprisingly well tolerated thanks to its antibacterial properties.
It's also worth remembering that skin changes with the seasons. In summer, when it's tanned and more resistant to acids, mandelic acid can work without triggering redness. In winter, when dry air takes its toll, lactic acid can be the answer to lost radiance and hydration.
When your pores "tell a story"
Combine or keep separate?
Lactic and mandelic acids aren't mutually exclusive — they can complement each other if your skin needs it. Combinations used in salons vary: ready-made formulas containing both acids at once, alternating treatments (a lactic session, then a mandelic session a few weeks later), or mandelic acid as a cleansing step followed by lactic acid to seal the barrier. Your cosmetologist decides whether a specific combination makes sense — based on a skin analysis, not an ingredients list.
Peel + mesotherapy
Exfoliated skin absorbs active ingredients more readily — a peel often precedes mesotherapy, boosting its results.
Peel + hydrating mask
After acid peels, especially lactic acid, salons often finish the treatment with intensive hydration — this stabilises the barrier and extends the glow.
Series of peels + photorejuvenation
Peels prepare the skin before laser or IPL treatments: removing the outer layer of skin means more even energy absorption and a better final result.
Peel + ultrasonic cleansing
Sonic cleansing and acid peels are often used together — between them, they address both mechanical impurities and uneven texture.
Results — what to realistically expect
Acid peels are well established in cosmetology, with well-documented results. Even so, it's worth approaching them with realistic expectations. These aren't one-off treatments, and they don't work the same way for everyone.
- After a series of sessions, many people notice a more even skin tone and less visible fine pigmentation.
- Skin often feels smoother to the touch — improved texture is one of the earliest results you'll notice.
- On oily, acne-prone skin, mandelic acid can reduce how often breakouts occur — though for some people the effect builds gradually and takes several sessions.
- On dry, dull skin, lactic acid often gives an immediate glow after just one session.
- Collagen stimulation — both acids, particularly at higher clinical concentrations, may support skin remodelling, though the effects are subtle and develop over time.