We use essential cookies (authentication, your saved goals/stack) by default. With your permission we'll also enable privacy-respecting analytics (Vercel Web Analytics, anonymous load-time metrics) and error-replay diagnostics (Sentry — DOM snapshots only when an error fires) so we can fix bugs faster. Learn more about cookies
Head-to-head evidence comparison — which supplement is right for you?
Niacinamide wins 1 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Mostly mechanism / observational
Top outcomes
Verdict
Mostly mechanism / observational
Top outcomes
Shared outcomes (2)
Outcomes where both Lactic Acid (topical) and Niacinamide have evidence — compare verdict strength side-by-side.
Topical cosmetic only. Leave-on lactic acid is used at roughly 5-12% (lower for hydration, higher for exfoliation); professional peels use higher strengths. Apply to clean skin, often at night, building frequency as tolerated, with daily sunscreen. There is no oral or systemic dose — it is not ingested. This library does not provide an ingestion protocol.
evening
Leave-on lotion or serum (≈5-12% lactic acid)
Topical cosmetic only. Niacinamide is typically formulated at 2-5% in leave-on serums, creams, or gels and applied to clean skin once or twice daily (AM and/or PM). It layers well under sunscreen and with most other actives. There is no oral, injectable, or systemic dose in this cosmetic context — it is not ingested here. This library does not provide an ingestion protocol.
any
Leave-on topical serum or cream (2-5% niacinamide)
Throughout
2-8 weeks
8-22 weeks
Throughout
Throughout
4-12 weeks
2-12 weeks
2-8 weeks
Topical 8% glycolic acid and 8% L-lactic acid creams for the treatment of photodamaged skin. A double-blind vehicle-controlled clinical trial.
Arch Dermatol (1996) · Rct · n=74
22-week double-blind vehicle-controlled trial (n=74): 8% L-lactic acid cream twice daily improved facial photodamage in 71% vs 40% with vehicle (P<.05)
Effect of lactic acid isomers on keratinocyte ceramide synthesis, stratum corneum lipid levels and stratum corneum barrier function.
Arch Dermatol Res (1996) · In vitro
Lactic acid stimulated keratinocyte ceramide biosynthesis in vitro, L-isomer far more potent (300% vs 100%)
Applications of hydroxy acids: classification, mechanisms, and photoactivity.
Clin Cosmet Investig Dermatol (2010) · Review
FDA/NIH review of alpha-, beta-, poly-, and bionic hydroxy acids across photoaging, pigmentation, acne, and ichthyosis
Niacinamide: A B vitamin that improves aging facial skin appearance.
Dermatol Surg (2005) · Rct · n=50
Double-blind, left-right randomized split-face design: 5% niacinamide vs vehicle applied twice daily for 12 weeks in 50 white women with facial photoaging
The effect of niacinamide on reducing cutaneous pigmentation and suppression of melanosome transfer.
Br J Dermatol (2002) · Rct · n=18
Paired clinical trial: 18 subjects with hyperpigmentation used 5% niacinamide vs vehicle moisturizer (plus a separate facial-tanning arm)
A Double-Blind, Randomized Clinical Trial of Niacinamide 4% versus Hydroquinone 4% in the Treatment of Melasma.
Dermatol Res Pract (2011) · Rct · n=27
Split-face RCT in 27 melasma patients: 4% niacinamide vs 4% hydroquinone (HQ) for 8 weeks, both with sunscreen
Niacinamide has a higher evidence score (6/10 vs 6/10) and wins in 1 of 3 categories.
For even skin tone, Niacinamide has a higher relevance score (75 vs 45).
No known interactions between Lactic Acid (topical) and Niacinamide have been documented in our database. However, always consult a healthcare provider before combining supplements.