The Ordinary Niacinamide 10% + Zinc 1% vs The Ordinary Salicylic Acid 2% Solution

In a randomized, placebo-controlled split-face study of 30 healthy Japanese women, a cosmetic containing 4% niacinamide reduced the skin-surface average roughness (Ra) value significantly more than the niacinamide-free control site after 8 weeks (P<0.05).

Human trial · 2008 · 30 people · healthy Japanese women with wrinkles in the eye areas · Skin-surface roughness measured by replica profilometry (Ra). · Measured at the eye area on a photoaged/wrinkle cohort; the endpoint is surface roughness.

PMID 19017042

In 20 people with Fitzpatrick skin types IV-V, a broad-spectrum sunscreen containing sclareolide and niacinamide significantly prevented experimentally induced post-inflammatory hyperpigmentation: in stripped, exposed zones the protected skin improved by +5.96 ITA degrees versus -9.88 in unprotected skin (net protection about 16 ITA degrees, p < 0.001).

Human trial · 2026 · 20 people · participants with Fitzpatrick skin types IV-V · People with darker skin phototypes (IV-V) prone to post-inflammatory hyperpigmentation, applying the sunscreen daily for 20 days under UV and visible-light exposure. · Small sample (20), within-subject controlled model of experimentally induced pigmentation; the abstract calls for comparative studies with and; industry involvement.

PMID 41240206

In 72 women with visible signs of ageing, a niacinamide-containing biomimetic lamellar cream significantly improved the Cutometer R5 elasticity parameter, wrinkle score, TEWL and corneometer values over 4 weeks compared against the untreated side.

Human trial · 2019 · 72 people · women with visible signs of ageing (Study 2) · Women with visible signs of ageing, applying the cream twice daily for 4 weeks. · Grading of high-resolution images failed to detect improvements in skin texture; proof-of-concept studies.

PMID 30414275

In 91 women with melasma, a skincare routine containing vitamin B3 (niacinamide) and 2-mercaptonicotinyl glycine significantly reduced MASI after 3 months, with roughly 38-41% reduction by 6 months.

Human trial · 2025 · 91 people · women with melasma · Women aged about 44 with melasma, phototypes III-IV, using the routine twice daily with daily SPF50+ sunscreen. · A clinically relevant difference favoured Kligman's triple combination in the first 3 months; industry-funded; skin radiance and fine wrinkles also improved.

PMID 41036635

In 83 adults with comedones, a serum containing salicylic acid and lipohydroxy acid significantly improved open comedones on the nose, closed comedones on the face, skin pore density, sebum secretion and skin hydration from baseline after 8 weeks; adding a mask improved closed comedones more than the serum alone (-6.56 vs -5.19, p = 0.022).

Human trial · 2023 · 83 people · adults with comedones (41 serum+mask, 42 serum alone) · Adults in Shanghai with comedones, PIE and PIH, using the serum for 8 weeks. · Both groups used active products; improvements were reported against baseline and between the two active groups. Industry-funded. This is the trial found that counted open and closed comedones separately.

PMID 36999489

The 2024 American Academy of Dermatology acne guideline lists topical salicylic acid as a conditional recommendation. Strong recommendations in the same guideline go to benzoyl peroxide, topical retinoids, topical antibiotics and oral doxycycline.

Clinical guideline · 2024 · Acne vulgaris in people aged nine and older, as covered by the guideline's scope.

PMID 38300170

In a randomized, double-blind, four-arm crossover study of 51 healthy volunteers with dry skin, an emollient containing glycerol and petrolatum raised corneometry-measured skin moisture significantly above its vehicle (P < 0.0001) over 12 hours. The authors attributed the hydration gain to the glycerol component and the lower water loss to the petrolatum component.

Human trial · 2020 · 51 people · healthy volunteers with dry skin (Kligman score 2 or 3) · Corneometry (skin moisture) and transepidermal water loss over 12 hours after one application. · Measured on the forearms. The significant hydration result comes from the full emollient containing both glycerol and petrolatum.

PMID 31532576

Topical glycerol improves stratum corneum hydration, barrier function and skin mechanical properties. The review also reports reduced irritation response and faster wound healing, and traces the effect to aquaporin-3 transport and to glycerol's own presence in the skin.

Review article · 2008 · Humans in the cited studies, plus animal and in-vitro work on mechanism · Leave-on products. The review discusses both healthy skin and skin with dry or barrier-impaired conditions such as atopic dermatitis. · A narrative review. It compiles mechanisms and results from other studies.

PMID 18510666