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Head-to-head evidence comparison — which supplement is right for you?
Vitamin C (topical) wins 2 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 (1)
Outcomes where both Benzoyl Peroxide and Vitamin C (topical) have evidence — compare verdict strength side-by-side.
Topical OTC use. Benzoyl peroxide is used at 2.5-10% in gels, creams, and washes, applied to acne-prone areas once or twice daily; lower strengths (2.5-5%) are usually as effective as 10% with less irritation. There is no oral or systemic dose — it is not ingested. It is often combined with a retinoid (e.g. adapalene) for greater effect. This library does not provide an ingestion protocol.
any
Leave-on gel/cream (2.5-5%) or a fixed combination with a retinoid
Topical cosmetic only. L-ascorbic acid serums are typically 10-20% (often near pH 3 for absorption); stable derivatives are used at varying percentages. Apply a few drops to clean, dry skin, usually in the morning under sunscreen (its antioxidant action complements SPF). There is no oral, injectable, or systemic dose in this cosmetic context. This library does not provide an ingestion protocol.
morning
Leave-on topical serum (10-20% L-ascorbic acid) or a stable vitamin C derivative
Throughout
4-12 weeks
Throughout
First weeks
Throughout
8-12 weeks
8-24 weeks
Throughout
Topical benzoyl peroxide for acne.
Cochrane Database Syst Rev (2020) · Systematic review
Pooled 120 RCTs (29,592 participants); BPO more effective than placebo/no treatment for participant-reported improvement (RR 1.27, 95% CI 1.12 to 1.45)
Efficacy of topical treatments for mild-to-moderate acne: A systematic review and meta-analysis of randomized control trials.
J Eur Acad Dermatol Venereol (2025) · Meta analysis
Network meta-analysis of 35 RCTs (33,472 participants) comparing nine topical acne agents
Adapalene-benzoyl peroxide, a fixed-dose combination for the treatment of acne vulgaris: results of a multicenter, randomized double-blind, controlled study.
J Am Acad Dermatol (2007) · Rct · n=517
517 subjects randomized double-blind to adapalene-BPO, adapalene, BPO, or vehicle for 12 weeks
Use of topical ascorbic acid and its effects on photodamaged skin topography.
Arch Otolaryngol Head Neck Surg (1999) · Rct · n=19
Split-face, randomized, double-blind, vehicle-controlled trial: active L-ascorbic acid serum vs vehicle daily for 3 months in mild-to-moderate facial photodamage
Topical ascorbic acid on photoaged skin. Clinical, topographical and ultrastructural evaluation: double-blind study vs. placebo.
Exp Dermatol (2003) · Rct
6-month double-blind randomized trial comparing 5% vitamin C cream vs its excipient on photoaged skin of the low-neck and arms
Efficacy of topical vitamin C in melasma and photoaging: A systematic review.
J Cosmet Dermatol (2023) · Systematic review
Systematic review of prospective RCTs of topical vitamin C in melasma or photodamage: 7 publications, 139 total volunteers
Vitamin C (topical) has a higher evidence score (6/10 vs 9/10) and wins in 2 of 3 categories.
No known interactions between Benzoyl Peroxide and Vitamin C (topical) have been documented in our database. However, always consult a healthcare provider before combining supplements.