Verified Beauty Data

Ingredient dossier Nº 019 / The verified record

Lactic Acid

LACTIC ACID · CosIng 73452 · also AHA, 2-hydroxypropanoic acid

Effective concentration, the pH it needs, how the derivatives compare, stability in the bottle, and the open questions — every scientific claim on this page links to its source.

Editorial verdict / Social intelligence

Qualified yes Ingredient dossier

The gentlest AHA with a bonus: it hydrates as it exfoliates — the go-to for sensitive and dry skin that needs chemical exfoliation without the burn. 1

Beauty benefit
Lactic acid is a dual-action AHA that both exfoliates and hydrates: it dissolves the bonds holding dead corneocytes at the stratum corneum surface (accelerating natural shedding to improve texture, tone, and clarity) while simultaneously functioning as a humectant and natural moisturizing factor (NMF) component that binds water in the stratum corneum. Its slightly larger molecular weight (90 Da vs glycolic acid's 76 Da) gives it a gentler penetration profile than glycolic acid, making it the most accessible AHA for dry, sensitive, or reactive skin. At 8–12% with adequate pH (3.0–4.5), clinical trials demonstrate measurable improvement in skin smoothness, firmness, hyperpigmentation, and early photoaging markers. The critical trade-off: like all AHAs, it increases UV photosensitivity and requires daily SPF.
Does it work
Yes — with solid but limited clinical evidence. Two key RCTs underpin the claims: Smith 1996 (PMID:8784274) showed 12% applied twice daily for 3 months produced statistically significant increases in epidermal and dermal firmness and thickness; Stiller 1996 (PMID:8651713) showed 8% L-lactic acid over 22 weeks improved photodamaged facial skin in 71% of participants and outperformed glycolic acid for mottled hyperpigmentation on forearms. The honest caveat is that the core trials are 30 years old and small; modern large-scale independent RCTs specific to lactic acid are lacking. Community experience aligns with the clinical data — gentler than glycolic, real texture and tone improvements, a forgiving entry point for AHA beginners. See the science below →

Consensus strength

Strong

Broad agreement across clinical research, cosmetic science databases, and editorial sources that lactic acid is effective for exfoliation, texture improvement, and mild photoaging correction, and that it is gentler than glycolic acid due to its larger molecular size and NMF humectant properties. The photosensitivity risk is universally acknowledged and class-level (Kaidbey 2003, PMID:12713551). The 'qualified' holy grail label rather than full 'yes' reflects genuine evidence gaps: cornerstone trials are old and small; photosensitization evidence is glycolic-acid-specific extrapolated to the AHA class; and lactic acid is not the fastest brightener for stubborn melasma. No credible source calls it overhyped — the mechanism and benefits are real and biochemically well-established.

01 / What it does

What it does

Lactic acid is an alpha-hydroxy acid (AHA; MW 90 Da; pKa 3.86) with a dual mechanism: it accelerates corneocyte desquamation by disrupting cohesion at the stratum corneum surface, and it acts as a humectant and natural moisturizing factor (NMF) component that binds water in the stratum corneum. Its slightly larger molecular weight compared to glycolic acid (76 Da) is generally associated with less deep penetration and milder irritation potential, making it the most common AHA choice for sensitive or dry skin types. At appropriate concentration and pH, consistent use improves skin texture, tone, and photoaging markers at both epidermal and dermal levels.

02 / Effective concentration

What percentage actually works

Effective range

5-12%

For leave-on consumer products, the CIR Expert Panel identifies 10% as the recommended maximum AHA concentration at pH ≥ 3.5. The best lactic-acid-specific RCT evidence spans 5-12%. The 12% twice-daily protocol (Smith 1996) produced both epidermal and dermal improvement; 5% produced epidermal but not dermal changes. In-office lactic acid peels typically use 30-50% or higher and must be applied by trained practitioners.

Lactic acid's bioavailability in a formulation depends on both concentration and pH — the undissociated free acid (pKa 3.86) is the penetrating form; above pH 3.86, more than half the molecule exists as the charged lactate anion and penetration diminishes rapidly. A nominally high-percentage product at pH 6 can deliver negligible free-acid activity. The Smith 1996 study (PMID:8784274) is the key concentration-response reference: 12% produced dermal as well as epidermal effects, 5% was limited to epidermis. An 8% lactic acid RCT (Stiller 1996, PMID:8651713) demonstrated comparable facial photodamage improvement to 8% glycolic acid over 22 weeks (71% vs 76% of participants achieving at least one grade improvement). Consumer products exceeding 10% in leave-on formulations fall outside CIR guidance and are not recommended for home use.

  • Study 12% lactic acid twice daily for 3 months produced statistically significant increases in epidermal and dermal firmness, skin thickness, and smoothness; 5% lactic acid produced epidermal but not dermal changes — establishing a concentration threshold between 5% and 12% for dermal remodeling. 2
  • Study 8% lactic acid cream over 22 weeks in a double-blind vehicle-controlled RCT (n=74 photodamaged women) achieved improvement in at least one photodamage grade in 71% of participants on the face, and produced broader benefits on forearms including mottled hyperpigmentation, sallowness, and roughness — comparable outcomes to 8% glycolic acid in the same trial. 3
  • Study The CIR Expert Panel recommended 10% AHAs as the maximum concentration for consumer leave-on products; products sold online frequently exceed this — 19 of 50 Amazon AHA products examined exceeded this guideline in one review. 7

One honest caveat Lactic-acid-specific high-quality RCT evidence is sparse. The most important clinical studies — Stiller 1996 (PMID:8651713) and Smith 1996 (PMID:8784274) — are small, are 30 years old, and have not been independently replicated with modern outcome measures. Much of the cited AHA evidence pools lactic acid with glycolic acid or treats them as equivalent class members.

03 / pH requirement

The pH it needs

Target pH

pH 3.0-4.5 for meaningful free-acid activity; CIR/FDA guidance recommends consumer products at pH ≥ 3.5

Lactic acid has a pKa of 3.86. At pH above its pKa, the majority of molecules exist as the charged lactate anion, which penetrates the stratum corneum poorly. At pH 3.5, roughly 70% of the acid is protonated and active; dropping to pH 3.0 increases the free-acid fraction to ~88% but also increases irritation risk substantially. The CIR Expert Panel, in line with FDA advisory guidance, recommends consumer leave-on AHA products be formulated at pH ≥ 3.5. This applies to lactic acid as it does to glycolic acid — the safety rationale and photosensitivity caveat are shared across the AHA class. Formulators evaluating lactic acid products should look at pH alongside stated concentration; a 10% lactic acid product at pH 5.5 has minimal exfoliating activity.

  • Study The CIR Expert Panel recommended that AHA-containing consumer leave-on products be formulated at pH 3.5 or above to reduce irritation while maintaining meaningful exfoliating activity; this limit applies across the AHA class including lactic acid. 7
  • Review Whether AHAs exfoliate beneficially or cause irritation and photosensitization depends on both concentration and pH; the dual effects of AHAs on skin are determined by these two interacting variables for the class as a whole. 6

04 / Derivative ladder

How the derivatives compare

Every derivative trades a measure of proven activity for stability or gentleness. Skin conversion is the question that matters — a more stable molecule only helps if your skin can turn it back into the active form.

  1. Ammonium Lactate

    AMMONIUM LACTATE

    Skin conversion not applicable — buffered ammonium salt of lactic acid

    The ammonium salt of lactic acid, partially neutralised so the formulation sits nearer skin-tolerable pH while retaining free-acid activity. 12% ammonium lactate (e.g. AmLactin, Lac-Hydrin) is the best-characterised lactic preparation for xerosis and ichthyosis, generally better tolerated than an equivalent free-acid concentration. It behaves as both a keratolytic and a humectant.

    Stability edge Buffered salt is less irritating at a usable pH than an equivalent free-acid lactic concentration; stable in standard aqueous lotions.

  2. Sodium Lactate

    SODIUM LACTATE

    Skin conversion not applicable — sodium salt of lactic acid

    The sodium salt of lactic acid and a natural component of the skin's own natural moisturizing factor (NMF). At cosmetic use levels it functions primarily as a humectant and pH buffer rather than an exfoliant — the fully neutralised salt has little free-acid keratolytic activity. Commonly paired with other humectants for hydration.

    Stability edge Highly stable, water-soluble humectant; used to buffer and hydrate rather than exfoliate.

05 / Stability & storage

Stability in the bottle

Lactic acid is chemically stable in acidic aqueous formulations and does not oxidize or photolyze at typical cosmetic concentrations. It does not require special packaging for stability, unlike oxidation-prone actives such as L-ascorbic acid. The primary stability concerns are pH drift over time (reducing free-acid fraction and exfoliant potency) and microbial contamination in water-based formulations, which requires adequate preservation. Lactic acid's stability profile is similar to glycolic acid and is not a limiting formulation factor. As a chiral molecule, both L- and D-lactic acid exist; most cosmetic-grade sources produce the L-form (also the biologically occurring NMF isomer), though racemic mixtures are also commercially available. The cosmetic literature does not establish a clinically meaningful activity difference between isomers in topical use.

In practice Buy it in an opaque, airless, or amber container, store it cool and out of the light, and treat a colour shift toward orange or brown as the signal to replace it — the molecule is telling you it has already oxidised.

06 / How to use it

How to actually use Lactic Acid

When
PM — After cleansing, before moisturizer.
Pairs well with
hydrating + soothing follow-up.
Apply apart from
retinol (same night), other acids(use one in the morning, the other at night — not “never together”)
What to look for
5–10% leave-on.
Heads-up
A gentler, hydrating AHA — good for dry/sensitive skin. SPF by day; start 1–2×/week.

Practical guidance for routine placement — not a substitute for a dermatologist’s advice for your skin.

07 / The database

Every Lactic Acid product, cheapest active-gram first

Ranked by $ per gram of active — what the working ingredient actually costs you, not the sticker price. Rows we have reviewed in full link through; the rest are data points from the same crawl.

Buy The Ordinary on Amazon $9.20 Top-ranked pick · affiliate link

# Product % Price $ / g of active
1 The Ordinary The Ordinary Lactic Acid 10% + HA Reviewed in full 10% $9.20 $3.11

Showing the 1 lowest-cost of 1 measured .

Contains it, but doesn't disclose a percentage: Sunday Riley Sunday Riley Good Genes All-In-One Lactic Acid Treatment

08 / Safety

Is it safe?

Reviewed by the Cosmetic Ingredient Review — safe as used

Safe as used for lactic acid in consumer products at concentrations ≤10% and pH ≥ 3.5, when accompanied by a photosensitivity/sunscreen advisory. Lactic acid falls under the CIR Expert Panel's AHA class review. Key conditions are identical to other AHAs: maximum 10% consumer leave-on concentration; pH ≥ 3.5; mandatory advisory that AHA use increases sun sensitivity and that a broad-spectrum sunscreen should be used during and for at least one week after use.

CRITICAL PHOTOSENSITIVITY: AHA use — including lactic acid — increases skin sensitivity to UV radiation. The photosensitization effect documented for the AHA class (Kaidbey et al. 2003, PMID:12713551 — using 10% glycolic acid as the test AHA) involves significantly increased sunburn cell formation and reduced minimal erythema dose; this reversed within one week of treatment discontinuation. Whether all AHAs confer equivalent photosensitization risk is not directly established (glycolic acid was the test agent in the Kaidbey trial), but the FDA and CIR advisory covers the AHA class collectively. Daily broad-spectrum SPF 30+ is non-negotiable during lactic acid use. At concentrations above 10% or pH below 3.5, irritation (stinging, burning, erythema, transient barrier disruption) is common and increases with concentration. Lactic acid is a direct irritant at low pH, not an allergic sensitizer in standard patch testing.

  • Study AHA photosensitization (increased sunburn cell formation, reduced minimal erythema dose after UV) was demonstrated in a 29-subject randomized double-blind clinical trial using 10% glycolic acid; the effect reversed within one week of discontinuing treatment. The FDA/CIR advisory requiring a sunscreen warning covers the AHA class. 5
  • Study The CIR Expert Panel recommended 10% AHA as the maximum consumer leave-on concentration and required a sunscreen advisory; only 16 of 50 AHA products sold on Amazon displayed the required warning — indicating widespread non-compliance. 7
  • Review AHAs including lactic acid can cause stinging, burning, and irritation, particularly at pH below 3.5 or at concentrations above those recommended for consumer leave-on products; the adverse effect profile is dose- and pH-dependent. 6

09 / The limits of the evidence

What we don't know yet

Most of what you read about this ingredient is stated with more certainty than the evidence earns. Here is exactly where the record thins out — so you can weigh the claims above for yourself.

  1. Lactic-acid-specific high-quality RCT evidence is sparse. The most important clinical studies — Stiller 1996 (PMID:8651713) and Smith 1996 (PMID:8784274) — are small, are 30 years old, and have not been independently replicated with modern outcome measures. Much of the cited AHA evidence pools lactic acid with glycolic acid or treats them as equivalent class members.
  2. The AHA photosensitization study (Kaidbey 2003, PMID:12713551) used glycolic acid as the test compound. Direct clinical evidence that lactic acid specifically induces equivalent UV photosensitization in a controlled human trial has not been published; the class-level FDA/CIR advisory extrapolates from glycolic acid data.
  3. Lactic acid's role as an NMF component and humectant is well established biochemically, but controlled RCT evidence specifically attributing in-use moisturization benefit to the NMF mechanism — rather than to occlusive or vehicle effects — is limited in the published literature.
  4. The Smith 1996 study (PMID:8784274) establishing the 5%-vs-12% concentration-response threshold for epidermal vs dermal effects was a small, short-duration study. The specific threshold has not been replicated or refined in subsequent independent RCTs with lactic acid.
  5. Comparative evidence for lactic acid in treating melasma or post-inflammatory hyperpigmentation as a solo agent (not in combination peels) is limited; most combination peel studies include multiple agents and cannot isolate lactic acid's contribution.
  6. Long-term safety data on daily consumer-concentration lactic acid use beyond 22-24 weeks are not well characterized in peer-reviewed literature; most RCTs run 8-24 weeks.
  7. The isomer question (L-lactic vs racemic/D-lactic acid) in topical formulations has not been rigorously studied in controlled clinical trials; the cosmetic literature does not establish a clinically meaningful activity difference between isomers for topical use.

10 / What people say

What formulators and users say

What works

  • Common Exfoliates gently while simultaneously hydrating — a dual mechanism unique among AHAs, because lactic acid is a component of the skin's natural moisturizing factor (NMF) and functions as a humectant 78
    It gently lifts off dead skin cells to reveal newer, fresher, smoother skin Editorial
  • Common Gentler than glycolic acid — its slightly larger molecule size is associated with more gradual penetration and lower irritation risk, making it the preferred AHA for sensitive and dry skin types 78
    lactic acid is more gentle due to its larger molecular size compared to glycolic acid Editorial
  • Common Clinically demonstrated to improve skin firmness, thickness, and smoothness — at 12% twice daily, Smith 1996 showed both epidermal AND dermal remodeling after 3 months; 5% produced epidermal changes only 27
    Treatment with 12% lactic acid resulted in increased epidermal and dermal firmness and thickness and clinical improvement in skin smoothness and in the appearance of lines and wrinkles. Study
  • Common Effective for hyperpigmentation and photoaged skin — Stiller 1996 showed 8% L-lactic acid cream improved mottled hyperpigmentation on forearms, outperforming glycolic acid on that specific endpoint 38
    L-Lactic acid cream was significantly superior to the vehicle in reducing mottled hyperpigmentation Study
  • Some Performs comparably to glycolic acid in head-to-head clinical trials — at 8%, both acids improved facial photodamage in 71% vs 76% of participants over 22 weeks with no clinically significant difference 3
    76% glycolic acid, 71% lactic acid, and 40% vehicle achieved facial improvement Study
  • Some High-concentration AHA treatment reverses measurable photoaging markers — Ditre 1996 demonstrated ~25% increase in skin thickness, improved collagen density, and improved elastic fiber quality with 6 months of AHA application 6
    Treatment with AHAs caused an approximate 25% increase in skin thickness. Study

What to know

  • Common Increases UV photosensitivity — like all AHAs, lactic acid makes skin more vulnerable to UV damage; daily SPF is mandatory during use and the effect reverses within one week of stopping 48
    Glycolic acid caused enhanced sensitivity to UV light measured as increased SBC induction and lowered MEDs. Study
  • Common Over-exfoliation is the primary misuse risk — using it too frequently or stacking with other actives causes redness, barrier damage, and peeling; skin should be exfoliated no more than 1–2 times per week initially 109
    skin should be exfoliated only one to two times per week to help expedite skin cell turnover without causing damage Editorial
  • Some Consumer products frequently exceed the CIR-recommended 10% maximum and most skip the mandatory sunscreen advisory — 19 of 50 Amazon AHA products exceeded concentration guidelines, and 34 of 50 lacked sunscreen warnings 5
    The Cosmetic Ingredient Review (CIR) Expert Panel recommended 10% of AHAs in products as the maximal safe concentration. Study
  • Some Can cause stinging, burning, and irritation at high concentrations or low pH — adverse effects increase sharply below pH 3.5 or above 10%; the dual beneficial and adverse effects are both concentration- and pH-dependent 1
    AHAs have been used as superficial peeling agents...However, caution should be exercised in relation to certain adverse reactions...including swelling, burning, and pruritus Study
  • Some Not the most dramatic brightener as a solo ingredient — works via surface exfoliation and keratinocyte turnover, not by inhibiting melanin synthesis; slower and subtler than dedicated depigmenting agents for stubborn melasma 87
    Chemical peels that contain AHAs, such as lactic acid, remove the top layer of dead skin cells. Editorial

What you'd only know from the reviews

  • Lactic acid is the only AHA that is also a natural moisturizing factor (NMF) component — it is natively present in corneocytes where it functions as a hygroscopic molecule binding water in the stratum corneum. This is why lactic acid can hydrate while glycolic acid cannot: they share an exfoliant mechanism but lactic acid has an additional built-in humectant mode that makes it uniquely suitable for dry and dehydrated skin types. 71

  • Concentration and pH are inseparable variables — a 10% lactic acid product at pH 5.5 delivers negligible free-acid exfoliant activity because above its pKa of 3.86 the molecule exists mostly as the non-penetrating lactate anion. The clinical trials used pH 3.5–4.5. Consumers buying high-percentage products without checking pH may see no exfoliation benefit at all; INCIDecoder flags pH 3–4 as the effective window for at-home products. 75

  • The 5% vs 12% concentration threshold matters clinically: at 5%, only epidermal changes are produced; at 12%, dermal remodeling (firmness, thickness) is additionally triggered. Most consumer products sit at 5–10%; the lower half of that range may not deliver the dermal anti-aging effects users expect — only surface texture improvements. 2

  • The AHA photosensitization evidence (Kaidbey 2003, PMID:12713551) used glycolic acid — not lactic acid specifically. The FDA and CIR extrapolate the class warning to all AHAs including lactic acid, but direct controlled human trial evidence for lactic acid's own photosensitization magnitude has never been published. The critical practical fact: the effect does reverse completely within one week of stopping use. 4

  • Lactic acid showed broader benefits for forearm hyperpigmentation than glycolic acid in the Stiller 1996 head-to-head RCT — an underreported finding. While both acids were roughly equivalent on facial photodamage, lactic acid was significantly superior to vehicle on mottled hyperpigmentation and sallowness on forearms, outperforming glycolic on those endpoints. This makes lactic acid the better-supported AHA choice when pigmentary concerns are the primary target. 3

  1. 1 Study Dual Effects of Alpha-Hydroxy Acids on the Skin — Molecules 2018 (Tang & Yang) 2018
  2. 2 Study Epidermal and dermal effects of topical lactic acid — J Am Acad Dermatol 1996 (Smith) 1996
  3. 3 Study Topical 8% glycolic acid and 8% L-lactic acid creams for the treatment of photodamaged skin. A double-blind vehicle-controlled clinical trial 1996
  4. 4 Study Topical glycolic acid enhances photodamage by ultraviolet light — Photodermatol Photoimmunol Photomed 2003 (Kaidbey et al.) 2003
  5. 5 Study Are cosmetics based on alpha hydroxy acids safe to use when purchased over the internet? — Toxicol Ind Health 2022 (Krstonošić & Ćirin) 2022
  6. 6 Study Effects of alpha-hydroxy acids on photoaged skin: a pilot clinical, histologic, and ultrastructural study — J Am Acad Dermatol 1996 (Ditre et al.) 1996
  7. 7 Editorial Lactic Acid — INCIDecoder Ingredient Profile 2024
  8. 8 Editorial Lactic Acid for Skin: Uses, Benefits, and More — Medical News Today 2024
  9. 9 Editorial When Beauty Products Cause Sun Sensitivity — Skin Cancer Foundation 2024
  10. 10 Editorial Are You Over-Exfoliating? How to Tell and Reverse the Damage — Healthline 2024

11 / Questions

Frequently asked

What does lactic acid actually do to skin?
Lactic acid works on two levels. First, as an AHA, it reduces cohesion between dead skin cells (corneocytes) at the stratum corneum surface, accelerating natural shedding and improving texture, tone, and clarity. Second, unlike glycolic acid, lactic acid is a component of the skin's natural moisturizing factor (NMF) and acts as a humectant — binding water in the outer skin layer and helping maintain hydration while exfoliating. At higher concentrations (12% twice daily in Smith 1996, PMID:8784274), it produces both epidermal and dermal improvements, including increased skin firmness and thickness. 26
Lactic acid vs glycolic acid — which should I use?
Neither is universally superior. A head-to-head RCT (Stiller 1996, PMID:8651713) found broadly comparable facial photodamage outcomes at 8% concentration over 22 weeks. The decision comes down to skin type and what you need from exfoliation. Glycolic acid (MW 76 Da) is smaller, penetrates more deeply, and is considered more potent — making it better for resilient skin focused on maximum photoaging correction. Lactic acid (MW 90 Da) is slightly larger, generally gentler, and doubles as a humectant — making it the better choice for sensitive, dry, or dehydrated skin that needs simultaneous hydration alongside exfoliation. 326
What percentage of lactic acid is most effective?
The best evidence comes from Smith 1996 (PMID:8784274): 12% twice daily produced both epidermal and dermal improvements (firmness, thickness, smoothness), while 5% was limited to epidermal changes only. Stiller 1996 (PMID:8651713) demonstrated significant facial photodamage improvement at 8%. For consumer leave-on products, the CIR Expert Panel recommends a maximum of 10% at pH ≥ 3.5. In-office peels use higher concentrations (30-70%) under controlled conditions. For most home users, 5-10% at pH 3.5-4.5 is the evidence-supported starting range; 10% is the upper ceiling for leave-on consumer products per safety guidance. 237
Does lactic acid increase sun sensitivity?
Yes — this is the most important safety consideration and applies to all AHAs. The clinical photosensitization study (Kaidbey et al. 2003, PMID:12713551) used 10% glycolic acid, but the FDA and CIR advisory covers the AHA class broadly including lactic acid. The photosensitization effect (more sunburn cell formation, lower threshold for UV damage) reverses within one week of stopping treatment. Practical rule: use broad-spectrum SPF 30+ sunscreen every morning during lactic acid use and for a week after stopping. This SPF requirement is mandatory advisory language on AHA consumer products. 57
Is lactic acid good for sensitive or dry skin?
Yes — lactic acid is generally considered the most accessible AHA for sensitive, dry, or reactive skin types, for two reasons. First, its slightly larger molecular size (MW 90 Da vs glycolic's 76 Da) is associated with more gradual penetration and a gentler irritation profile. Second, its role as a natural moisturizing factor (NMF) component means it simultaneously attracts and retains water in the stratum corneum while exfoliating — a dual benefit glycolic acid does not provide. Start at 5%, every other day, at pH ≥ 3.5, and build frequency as tolerance develops. 692
Can lactic acid help with hyperpigmentation or dark spots?
Yes, with consistent use. Lactic acid addresses hyperpigmentation primarily through accelerated keratinocyte turnover that removes hyperpigmented surface cells. The Stiller 1996 RCT (PMID:8651713) found 8% lactic acid cream produced greater improvements in mottled hyperpigmentation and sallowness on the forearms than glycolic acid in the same trial. The Ditre 1996 AHA study (PMID:8642081) demonstrated that high-concentration AHA treatment reverses photoaging markers — of which pigmentary changes are a component. Important caveat: lactic acid's photosensitizing effect is particularly consequential when treating pigmentation — unprotected UV exposure during AHA treatment can worsen the pigmentation being targeted. 345
Can I use lactic acid every day?
At typical consumer concentrations (5-10%) and pH 3.5-4.5, daily use was the protocol in the Stiller 1996 RCT (PMID:8651713) and is tolerated by most non-sensitive skin types. Sensitive skin usually does better at every-other-day or twice-weekly frequency, especially when starting. Daily use requires daily broad-spectrum SPF 30+ sunscreen — the photosensitization risk documented for the AHA class (Kaidbey 2003, PMID:12713551) applies to consistent AHA use at this frequency. Build frequency gradually; skin tolerance to lactic acid generally develops over 2-4 weeks. 35

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More from the verified record

12 / References

Sources

9 references · verified 2026-06-13
  1. 1

    Control of keratinization with alpha-hydroxy acids and related compounds. I. Topical treatment of ichthyotic disorders

    Van Scott EJ, Yu RJ · Archives of Dermatology 110(4):586-90 · 1974

  2. 2

    Epidermal and dermal effects of topical lactic acid

    Smith WP · Journal of the American Academy of Dermatology 35(3 Pt 1):388-91 · 1996

  3. 3

    Topical 8% glycolic acid and 8% L-lactic acid creams for the treatment of photodamaged skin. A double-blind vehicle-controlled clinical trial

    Stiller MJ, Bartolone J, Stern R, Smith S, Kollias N, Gillies R, Drake LA · Archives of Dermatology 132(6):631-6 · 1996

  4. 4

    Effects of alpha-hydroxy acids on photoaged skin: a pilot clinical, histologic, and ultrastructural study

    Ditre CM, Griffin TD, Murphy GF, Sueki H, Telegan B, Johnson WC, Yu RJ, Van Scott EJ · Journal of the American Academy of Dermatology 34(2 Pt 1):187-95 · 1996

  5. 5

    Topical glycolic acid enhances photodamage by ultraviolet light

    Kaidbey K, Sutherland B, Bennett P, Wamer WG, Barton C, Dennis D, Kornhauser A · Photodermatology, Photoimmunology and Photomedicine 19(1):21-7 · 2003

  6. 6

    Dual Effects of Alpha-Hydroxy Acids on the Skin

    Tang SC, Yang JH · Molecules 23(4):863 · 2018

  7. 7

    Are cosmetics based on alpha hydroxy acids safe to use when purchased over the internet?

    Krstonošić V, Ćirin D · Toxicology and Industrial Health 38(12):835-838 · 2022

  8. 8

    Alpha-hydroxyacids in the treatment of signs of photoaging

    Van Scott EJ, Ditre CM, Yu RJ · Clinics in Dermatology 14(2):217-26 · 1996

  9. 9

    Hydroxy Acids, the Most Widely Used Anti-aging Agents

    Moghimipour E · Jundishapur Journal of Natural Pharmaceutical Products 7(1):9-10 · 2012