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?
Lactic Acid (topical) vs Sunscreen (SPF): Sunscreen (SPF) has the stronger overall evidence (9 vs 6/10); they're alternatives for reduce wrinkles & fine lines — the best pick depends on your goals. Take the 60-second quiz for a pick tailored to your goals.
Sunscreen (SPF) wins 3 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Too few graded studies
Top outcomes
Verdict
Too few graded studies
Top outcomes
Shared outcomes (2)
Outcomes where both Lactic Acid (topical) and Sunscreen (SPF) 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 OTC. Apply a broad-spectrum SPF 30+ sunscreen daily to sun-exposed skin as the last step of a morning routine, using an adequate amount (about 2 mg/cm² — roughly a nickel-sized dollop for the face, a shot-glass for the body) and reapply every ~2 hours of sun exposure and after swimming/sweating. Mineral (zinc oxide / titanium dioxide) filters are preferred if you're concerned about systemic absorption. There is no oral or systemic dose — it is not ingested. This library does not provide an ingestion protocol.
Morning
Broad-spectrum SPF 30+, applied daily; mineral (zinc oxide/titanium dioxide) if concerned about absorption
Throughout
2-8 weeks
8-22 weeks
Throughout
Throughout
Ongoing (years)
Ongoing
Throughout
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) · Rct
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
Sunscreen and prevention of skin aging: a randomized trial.
Ann Intern Med (2013) · Rct · n=903
Randomized community trial (n=903): the daily sunscreen group showed no detectable increase in photoaging (skin microtopography) after 4.5 years
Molecular mechanisms of photoaging and its prevention by retinoic acid: ultraviolet irradiation induces MAP kinase signal transduction cascades that induce Ap-1-regulated matrix metalloproteinases that degrade human skin in vivo.
J Investig Dermatol Symp Proc (1998) · Review
Mechanistic model: UV activates MAP-kinase pathways and AP-1, which upregulate matrix metalloproteinases (MMPs)
Daily Use of a Facial Broad Spectrum Sunscreen Over One-Year Significantly Improves Clinical Evaluation of Photoaging.
Dermatol Surg (2016) · Open label · n=32
Single-arm prospective study (n=32): broad-spectrum SPF 30 applied daily to the face for 52 weeks
Sunscreen (SPF) has a higher evidence score (9/10 vs 6/10) and wins in 3 of 3 categories.
For reduce wrinkles & fine lines, Sunscreen (SPF) has a higher relevance score (90 vs 50).
No documented interaction was found in the data searched. This does not establish that this exact combination is safe.
The right pick depends on your goals. Answer a few quick questions for a personalised recommendation — or dig into the full evidence on each.