Best for Acne & breakouts

Review of how moisturizers affect the epidermal barrier: humectants such as glycerin increase stratum corneum hydration and can strengthen barrier function and resistance to irritation, although effects depend on formulation and some moisturizers may weaken the barrier; supports well-formulated glycerin-containing emollients for dry, barrier-impaired skin.

Review establishing glycerin as the gold standard humectant: attracts water to stratum corneum via hydrogen bonding, improves skin mechanical properties (elasticity, pliability), enhances desmosome degradation for smooth desquamation, and modulates aquaporin-3 channels; effective at 2-20% in topical formulations

Comprehensive review of moisturization mechanisms: glycerin contributes to corneocyte hydration by replacing lost natural moisturizing factor (NMF) components; maintains stratum corneum fluidity at low humidity; superior humectant performance vs propylene glycol, sorbitol, and urea in controlled comparisons

0.3% adapalene achieved superior reduction in inflammatory and non-inflammatory lesions vs 0.1%, with acceptable tolerability.

Meta-analysis: Meta analysis of five RCTs confirming adapalene class effect.

Randomized controlled trial (n=653, 12 weeks): Pivotal adapalene 0.3 vs 0.1 vs vehicle phase 3.

Randomized controlled trial (n=609, 12 weeks): Replicates Mills 1986 finding in Asian skin with larger n; 72.7% vs 75.0% vs 41.7% lesion reduction 2.5 vs 5 vs placebo.

Comparable acne reduction to tretinoin with significantly less irritation, dryness, and erythema.

Systematic review: Current evidence synthesis confirming BPO efficacy for acne moderate certainty of evidence.

Randomized controlled trial (n=153, 8 weeks): Efficacy equivalence across concentrations with tolerability advantage for 2.5%.

Clinical review of fragrance contact allergy: an estimated 1.7-4.1% of the general population is sensitized to fragrance-mix ingredients and about 10% of patch-tested eczema patients react; fragrance materials occur in 15-100% of cosmetic products; allergy predominates in women with facial or hand eczema.

Systematic review of keratolytics and emollients in psoriasis therapy: salicylic acid is a key keratolytic that removes psoriatic scale and improves penetration of co-applied topical agents; supports salicylic acid as an evidence-based adjunctive (descaling) treatment rather than a standalone therapy.

Comprehensive review: salicylic acid (2%) is the only lipophilic BHA, enabling comedolytic and anti-inflammatory activity within the pilosebaceous unit; effective for acne vulgaris, melasma, photodamage, and keratosis pilaris; 20-30% SA peels show efficacy comparable to glycolic acid peels with lower erythema risk in Fitzpatrick IV-VI

Review confirms dermal HA declines ~50% by age 70; topical HA penetration is MW-dependent (fragments <50 kDa penetrate deeper but may paradoxically stimulate inflammation); multi-weight formulations balance hydration and penetration depth

Mechanistic review: niacinamide inhibits melanosome transfer via PAR-2 downregulation, upregulates ceramide and fatty acid synthesis for barrier repair, and reduces TEWL; Korean government-funded with no industry conflicts; notes most clinical trials are industry-sponsored

Systematic review establishing fragrance as the leading cause of cosmetic contact dermatitis, responsible for 30-45% of cosmetic adverse reactions; covers both irritant (direct keratinocyte damage) and allergic (hapten-driven type IV hypersensitivity) mechanisms; identifies cinnamal, hydroxycitronellal, and oakmoss as top individual allergens

Applied EU CLP hazard-classification criteria (EC 1272/2008) to personal care products: nearly all contained ingredients that would trigger hazard labelling—85% for eye effects and 52% for skin effects (including sensitizers such as fragrance allergens)—yet cosmetics are exempt from CLP labelling, leaving consumers under-informed about these hazards.

Azelaic acid 20% cream was superior to hydroquinone 2% cream for facial melasma in dark-skinned patients, with 73% achieving good-to-excellent results versus 19%. Both treatments caused transient mild-to-moderate irritation.

Single-blind RCT (n=46, 12 weeks) in mild-to-moderate acne comparing salicylic acid 3% plus clindamycin with tretinoin 0.05% plus clindamycin: both significantly reduced inflammatory and non-inflammatory lesion counts; tretinoin acted faster (significant by week 2) but groups were comparable at 12 weeks, and both were well tolerated.

This review of four placebo-controlled clinical studies and a comedolytic assay found that 0.5% and 2% salicylic acid pads reduced the number and severity of acne lesions in mild-to-moderate acne vulgaris. Comparative data showed salicylic acid superior to benzoyl peroxide, with adverse effects limited to mild local irritation.

Clinical review of fragrance contact allergy: an estimated 1.7-4.1% of the general population is sensitized to fragrance-mix ingredients and about 10% of patch-tested eczema patients react; fragrance materials occur in 15-100% of cosmetic products; allergy predominates in women with facial or hand eczema.

Network meta-analysis of 23 RCTs (n=3,905) of topical interventions for facial photoaging: isotretinoin, retinol and tretinoin significantly improved fine wrinkles (isotretinoin ranked highest); tazarotene was most effective for coarse wrinkles and glycolic acid for roughness; tretinoin and retinol were superior for hyperpigmentation, with tretinoin showing the most favorable safety profile.

Meta-analysis of 8 RCTs (n=1,361) of topical tretinoin, the active retinoid to which retinol is metabolized in skin, for photodamaged facial skin: tretinoin significantly improved fine wrinkles (mean difference 0.41) and coarse wrinkles (MD 0.25) versus control, with more frequent skin irritation (OR 3.14).

Systematic review of keratolytics and emollients in psoriasis therapy: salicylic acid is a key keratolytic that removes psoriatic scale and improves penetration of co-applied topical agents; supports salicylic acid as an evidence-based adjunctive (descaling) treatment rather than a standalone therapy.

Systematic review establishing fragrance as the leading cause of cosmetic contact dermatitis, responsible for 30-45% of cosmetic adverse reactions; covers both irritant (direct keratinocyte damage) and allergic (hapten-driven type IV hypersensitivity) mechanisms; identifies cinnamal, hydroxycitronellal, and oakmoss as top individual allergens

Applied EU CLP hazard-classification criteria (EC 1272/2008) to personal care products: nearly all contained ingredients that would trigger hazard labelling—85% for eye effects and 52% for skin effects (including sensitizers such as fragrance allergens)—yet cosmetics are exempt from CLP labelling, leaving consumers under-informed about these hazards.

Comprehensive review: salicylic acid (2%) is the only lipophilic BHA, enabling comedolytic and anti-inflammatory activity within the pilosebaceous unit; effective for acne vulgaris, melasma, photodamage, and keratosis pilaris; 20-30% SA peels show efficacy comparable to glycolic acid peels with lower erythema risk in Fitzpatrick IV-VI

Azelaic acid 20% cream was superior to hydroquinone 2% cream for facial melasma in dark-skinned patients, with 73% achieving good-to-excellent results versus 19%. Both treatments caused transient mild-to-moderate irritation.

Topical retinol (vitamin A) applied to naturally aged, sun-protected human skin antagonized the age-related decline in fibroblast growth and the elevated collagen-degrading matrix metalloproteinases, and stimulated new collagen synthesis, supporting retinol's ability to reverse molecular markers of dermal aging.

Systematic review: Consolidated rosacea evidence confirming efficacy.

Systematic review of keratolytics and emollients in psoriasis therapy: salicylic acid is a key keratolytic that removes psoriatic scale and improves penetration of co-applied topical agents; supports salicylic acid as an evidence-based adjunctive (descaling) treatment rather than a standalone therapy.

Network meta-analysis (23 RCTs, 3,905 participants) of topical photoaging treatments ranked glycolic acid highest for reducing skin roughness (ahead of retinol and tretinoin), reflecting its exfoliating/desquamating action; however glycolic acid carried a higher adverse-event risk than topical retinoids.

Review of how moisturizers affect the epidermal barrier: humectants such as glycerin increase stratum corneum hydration and can strengthen barrier function and resistance to irritation, although effects depend on formulation and some moisturizers may weaken the barrier; supports well-formulated glycerin-containing emollients for dry, barrier-impaired skin.

Review establishing glycerin as the gold standard humectant: attracts water to stratum corneum via hydrogen bonding, improves skin mechanical properties (elasticity, pliability), enhances desmosome degradation for smooth desquamation, and modulates aquaporin-3 channels; effective at 2-20% in topical formulations

Comprehensive review of moisturization mechanisms: glycerin contributes to corneocyte hydration by replacing lost natural moisturizing factor (NMF) components; maintains stratum corneum fluidity at low humidity; superior humectant performance vs propylene glycol, sorbitol, and urea in controlled comparisons

Mechanistic review: niacinamide inhibits melanosome transfer via PAR-2 downregulation, upregulates ceramide and fatty acid synthesis for barrier repair, and reduces TEWL; Korean government-funded with no industry conflicts; notes most clinical trials are industry-sponsored

Comprehensive review: salicylic acid (2%) is the only lipophilic BHA, enabling comedolytic and anti-inflammatory activity within the pilosebaceous unit; effective for acne vulgaris, melasma, photodamage, and keratosis pilaris; 20-30% SA peels show efficacy comparable to glycolic acid peels with lower erythema risk in Fitzpatrick IV-VI

Azelaic acid 20% cream was superior to hydroquinone 2% cream for facial melasma in dark-skinned patients, with 73% achieving good-to-excellent results versus 19%. Both treatments caused transient mild-to-moderate irritation.

Vehicle-controlled in vivo study: forearm skin treated with 20% glycolic acid lotion twice daily for 3 months showed significantly increased epidermal and dermal hyaluronic acid and type I collagen gene expression (mRNA) versus vehicle, indicating glycolic-acid-induced extracellular matrix remodeling of human skin.

RCT (n=197 atopic dermatitis patients): a 20% glycerin cream, its glycerin-free base, and a 4% urea/4% NaCl cream were applied daily for 30 days. Glycerin and the comparators had equal effects on skin dryness; glycerin caused significantly less smarting than the urea-saline cream (10% vs 24%, p<0.0006).

Clinical review of fragrance contact allergy: an estimated 1.7-4.1% of the general population is sensitized to fragrance-mix ingredients and about 10% of patch-tested eczema patients react; fragrance materials occur in 15-100% of cosmetic products; allergy predominates in women with facial or hand eczema.

Systematic review of keratolytics and emollients in psoriasis therapy: salicylic acid is a key keratolytic that removes psoriatic scale and improves penetration of co-applied topical agents; supports salicylic acid as an evidence-based adjunctive (descaling) treatment rather than a standalone therapy.

Network meta-analysis (23 RCTs, 3,905 participants) of topical photoaging treatments ranked glycolic acid highest for reducing skin roughness (ahead of retinol and tretinoin), reflecting its exfoliating/desquamating action; however glycolic acid carried a higher adverse-event risk than topical retinoids.

Review of how moisturizers affect the epidermal barrier: humectants such as glycerin increase stratum corneum hydration and can strengthen barrier function and resistance to irritation, although effects depend on formulation and some moisturizers may weaken the barrier; supports well-formulated glycerin-containing emollients for dry, barrier-impaired skin.

Review establishing glycerin as the gold standard humectant: attracts water to stratum corneum via hydrogen bonding, improves skin mechanical properties (elasticity, pliability), enhances desmosome degradation for smooth desquamation, and modulates aquaporin-3 channels; effective at 2-20% in topical formulations

Comprehensive review of moisturization mechanisms: glycerin contributes to corneocyte hydration by replacing lost natural moisturizing factor (NMF) components; maintains stratum corneum fluidity at low humidity; superior humectant performance vs propylene glycol, sorbitol, and urea in controlled comparisons

Mechanistic review: niacinamide inhibits melanosome transfer via PAR-2 downregulation, upregulates ceramide and fatty acid synthesis for barrier repair, and reduces TEWL; Korean government-funded with no industry conflicts; notes most clinical trials are industry-sponsored

Comprehensive review: salicylic acid (2%) is the only lipophilic BHA, enabling comedolytic and anti-inflammatory activity within the pilosebaceous unit; effective for acne vulgaris, melasma, photodamage, and keratosis pilaris; 20-30% SA peels show efficacy comparable to glycolic acid peels with lower erythema risk in Fitzpatrick IV-VI

Systematic review establishing fragrance as the leading cause of cosmetic contact dermatitis, responsible for 30-45% of cosmetic adverse reactions; covers both irritant (direct keratinocyte damage) and allergic (hapten-driven type IV hypersensitivity) mechanisms; identifies cinnamal, hydroxycitronellal, and oakmoss as top individual allergens

Applied EU CLP hazard-classification criteria (EC 1272/2008) to personal care products: nearly all contained ingredients that would trigger hazard labelling—85% for eye effects and 52% for skin effects (including sensitizers such as fragrance allergens)—yet cosmetics are exempt from CLP labelling, leaving consumers under-informed about these hazards.

Systematic review of keratolytics and emollients in psoriasis therapy: salicylic acid is a key keratolytic that removes psoriatic scale and improves penetration of co-applied topical agents; supports salicylic acid as an evidence-based adjunctive (descaling) treatment rather than a standalone therapy.

Mechanistic review: niacinamide inhibits melanosome transfer via PAR-2 downregulation, upregulates ceramide and fatty acid synthesis for barrier repair, and reduces TEWL; Korean government-funded with no industry conflicts; notes most clinical trials are industry-sponsored

Review of how moisturizers affect the epidermal barrier: humectants such as glycerin increase stratum corneum hydration and can strengthen barrier function and resistance to irritation, although effects depend on formulation and some moisturizers may weaken the barrier; supports well-formulated glycerin-containing emollients for dry, barrier-impaired skin.

Review establishing glycerin as the gold standard humectant: attracts water to stratum corneum via hydrogen bonding, improves skin mechanical properties (elasticity, pliability), enhances desmosome degradation for smooth desquamation, and modulates aquaporin-3 channels; effective at 2-20% in topical formulations

Comprehensive review of moisturization mechanisms: glycerin contributes to corneocyte hydration by replacing lost natural moisturizing factor (NMF) components; maintains stratum corneum fluidity at low humidity; superior humectant performance vs propylene glycol, sorbitol, and urea in controlled comparisons

Comprehensive review: salicylic acid (2%) is the only lipophilic BHA, enabling comedolytic and anti-inflammatory activity within the pilosebaceous unit; effective for acne vulgaris, melasma, photodamage, and keratosis pilaris; 20-30% SA peels show efficacy comparable to glycolic acid peels with lower erythema risk in Fitzpatrick IV-VI

Azelaic acid 20% cream was superior to hydroquinone 2% cream for facial melasma in dark-skinned patients, with 73% achieving good-to-excellent results versus 19%. Both treatments caused transient mild-to-moderate irritation.

Systematic review: Consolidated rosacea evidence confirming efficacy.

Niacinamide 4% comparable to hydroquinone 4% for melasma treatment (MASI reduction 43% vs 55%, p=ns); niacinamide showed significantly fewer side effects (0% vs 18% irritation); independently funded with no industry involvement

Systematic review: Breastfeeding nipple pain evidence consolidation including panthenol as lanolin alternative.

Systematic review of keratolytics and emollients in psoriasis therapy: salicylic acid is a key keratolytic that removes psoriatic scale and improves penetration of co-applied topical agents; supports salicylic acid as an evidence-based adjunctive (descaling) treatment rather than a standalone therapy.

Mechanistic review: niacinamide inhibits melanosome transfer via PAR-2 downregulation, upregulates ceramide and fatty acid synthesis for barrier repair, and reduces TEWL; Korean government-funded with no industry conflicts; notes most clinical trials are industry-sponsored

Review of how moisturizers affect the epidermal barrier: humectants such as glycerin increase stratum corneum hydration and can strengthen barrier function and resistance to irritation, although effects depend on formulation and some moisturizers may weaken the barrier; supports well-formulated glycerin-containing emollients for dry, barrier-impaired skin.

Review establishing glycerin as the gold standard humectant: attracts water to stratum corneum via hydrogen bonding, improves skin mechanical properties (elasticity, pliability), enhances desmosome degradation for smooth desquamation, and modulates aquaporin-3 channels; effective at 2-20% in topical formulations

Comprehensive review of moisturization mechanisms: glycerin contributes to corneocyte hydration by replacing lost natural moisturizing factor (NMF) components; maintains stratum corneum fluidity at low humidity; superior humectant performance vs propylene glycol, sorbitol, and urea in controlled comparisons

Comprehensive review: salicylic acid (2%) is the only lipophilic BHA, enabling comedolytic and anti-inflammatory activity within the pilosebaceous unit; effective for acne vulgaris, melasma, photodamage, and keratosis pilaris; 20-30% SA peels show efficacy comparable to glycolic acid peels with lower erythema risk in Fitzpatrick IV-VI

Review confirms dermal HA declines ~50% by age 70; topical HA penetration is MW-dependent (fragments <50 kDa penetrate deeper but may paradoxically stimulate inflammation); multi-weight formulations balance hydration and penetration depth

Azelaic acid 20% cream was superior to hydroquinone 2% cream for facial melasma in dark-skinned patients, with 73% achieving good-to-excellent results versus 19%. Both treatments caused transient mild-to-moderate irritation.

Niacinamide 4% comparable to hydroquinone 4% for melasma treatment (MASI reduction 43% vs 55%, p=ns); niacinamide showed significantly fewer side effects (0% vs 18% irritation); independently funded with no industry involvement

RCT (n=197 atopic dermatitis patients): a 20% glycerin cream, its glycerin-free base, and a 4% urea/4% NaCl cream were applied daily for 30 days. Glycerin and the comparators had equal effects on skin dryness; glycerin caused significantly less smarting than the urea-saline cream (10% vs 24%, p<0.0006).

Systematic review of keratolytics and emollients in psoriasis therapy: salicylic acid is a key keratolytic that removes psoriatic scale and improves penetration of co-applied topical agents; supports salicylic acid as an evidence-based adjunctive (descaling) treatment rather than a standalone therapy.

Mechanistic review: niacinamide inhibits melanosome transfer via PAR-2 downregulation, upregulates ceramide and fatty acid synthesis for barrier repair, and reduces TEWL; Korean government-funded with no industry conflicts; notes most clinical trials are industry-sponsored

Review of how moisturizers affect the epidermal barrier: humectants such as glycerin increase stratum corneum hydration and can strengthen barrier function and resistance to irritation, although effects depend on formulation and some moisturizers may weaken the barrier; supports well-formulated glycerin-containing emollients for dry, barrier-impaired skin.

Review establishing glycerin as the gold standard humectant: attracts water to stratum corneum via hydrogen bonding, improves skin mechanical properties (elasticity, pliability), enhances desmosome degradation for smooth desquamation, and modulates aquaporin-3 channels; effective at 2-20% in topical formulations

Comprehensive review of moisturization mechanisms: glycerin contributes to corneocyte hydration by replacing lost natural moisturizing factor (NMF) components; maintains stratum corneum fluidity at low humidity; superior humectant performance vs propylene glycol, sorbitol, and urea in controlled comparisons

Comprehensive review: salicylic acid (2%) is the only lipophilic BHA, enabling comedolytic and anti-inflammatory activity within the pilosebaceous unit; effective for acne vulgaris, melasma, photodamage, and keratosis pilaris; 20-30% SA peels show efficacy comparable to glycolic acid peels with lower erythema risk in Fitzpatrick IV-VI

Review confirms dermal HA declines ~50% by age 70; topical HA penetration is MW-dependent (fragments <50 kDa penetrate deeper but may paradoxically stimulate inflammation); multi-weight formulations balance hydration and penetration depth

Azelaic acid 20% cream was superior to hydroquinone 2% cream for facial melasma in dark-skinned patients, with 73% achieving good-to-excellent results versus 19%. Both treatments caused transient mild-to-moderate irritation.

Niacinamide 4% comparable to hydroquinone 4% for melasma treatment (MASI reduction 43% vs 55%, p=ns); niacinamide showed significantly fewer side effects (0% vs 18% irritation); independently funded with no industry involvement

RCT (n=197 atopic dermatitis patients): a 20% glycerin cream, its glycerin-free base, and a 4% urea/4% NaCl cream were applied daily for 30 days. Glycerin and the comparators had equal effects on skin dryness; glycerin caused significantly less smarting than the urea-saline cream (10% vs 24%, p<0.0006).

Systematic review of keratolytics and emollients in psoriasis therapy: salicylic acid is a key keratolytic that removes psoriatic scale and improves penetration of co-applied topical agents; supports salicylic acid as an evidence-based adjunctive (descaling) treatment rather than a standalone therapy.

Mechanistic review: niacinamide inhibits melanosome transfer via PAR-2 downregulation, upregulates ceramide and fatty acid synthesis for barrier repair, and reduces TEWL; Korean government-funded with no industry conflicts; notes most clinical trials are industry-sponsored

Review of how moisturizers affect the epidermal barrier: humectants such as glycerin increase stratum corneum hydration and can strengthen barrier function and resistance to irritation, although effects depend on formulation and some moisturizers may weaken the barrier; supports well-formulated glycerin-containing emollients for dry, barrier-impaired skin.

Review establishing glycerin as the gold standard humectant: attracts water to stratum corneum via hydrogen bonding, improves skin mechanical properties (elasticity, pliability), enhances desmosome degradation for smooth desquamation, and modulates aquaporin-3 channels; effective at 2-20% in topical formulations

Comprehensive review of moisturization mechanisms: glycerin contributes to corneocyte hydration by replacing lost natural moisturizing factor (NMF) components; maintains stratum corneum fluidity at low humidity; superior humectant performance vs propylene glycol, sorbitol, and urea in controlled comparisons

Comprehensive review: salicylic acid (2%) is the only lipophilic BHA, enabling comedolytic and anti-inflammatory activity within the pilosebaceous unit; effective for acne vulgaris, melasma, photodamage, and keratosis pilaris; 20-30% SA peels show efficacy comparable to glycolic acid peels with lower erythema risk in Fitzpatrick IV-VI

Azelaic acid 20% cream was superior to hydroquinone 2% cream for facial melasma in dark-skinned patients, with 73% achieving good-to-excellent results versus 19%. Both treatments caused transient mild-to-moderate irritation.

Systematic review: Consolidated rosacea evidence confirming efficacy.

Niacinamide 4% comparable to hydroquinone 4% for melasma treatment (MASI reduction 43% vs 55%, p=ns); niacinamide showed significantly fewer side effects (0% vs 18% irritation); independently funded with no industry involvement

Systematic review: Breastfeeding nipple pain evidence consolidation including panthenol as lanolin alternative.

Systematic review of keratolytics and emollients in psoriasis therapy: salicylic acid is a key keratolytic that removes psoriatic scale and improves penetration of co-applied topical agents; supports salicylic acid as an evidence-based adjunctive (descaling) treatment rather than a standalone therapy.

Network meta-analysis (23 RCTs, 3,905 participants) of topical photoaging treatments ranked glycolic acid highest for reducing skin roughness (ahead of retinol and tretinoin), reflecting its exfoliating/desquamating action; however glycolic acid carried a higher adverse-event risk than topical retinoids.

Comprehensive review: salicylic acid (2%) is the only lipophilic BHA, enabling comedolytic and anti-inflammatory activity within the pilosebaceous unit; effective for acne vulgaris, melasma, photodamage, and keratosis pilaris; 20-30% SA peels show efficacy comparable to glycolic acid peels with lower erythema risk in Fitzpatrick IV-VI

Review of how moisturizers affect the epidermal barrier: humectants such as glycerin increase stratum corneum hydration and can strengthen barrier function and resistance to irritation, although effects depend on formulation and some moisturizers may weaken the barrier; supports well-formulated glycerin-containing emollients for dry, barrier-impaired skin.

Review establishing glycerin as the gold standard humectant: attracts water to stratum corneum via hydrogen bonding, improves skin mechanical properties (elasticity, pliability), enhances desmosome degradation for smooth desquamation, and modulates aquaporin-3 channels; effective at 2-20% in topical formulations

Comprehensive review of moisturization mechanisms: glycerin contributes to corneocyte hydration by replacing lost natural moisturizing factor (NMF) components; maintains stratum corneum fluidity at low humidity; superior humectant performance vs propylene glycol, sorbitol, and urea in controlled comparisons

Review confirms dermal HA declines ~50% by age 70; topical HA penetration is MW-dependent (fragments <50 kDa penetrate deeper but may paradoxically stimulate inflammation); multi-weight formulations balance hydration and penetration depth

Azelaic acid 20% cream was superior to hydroquinone 2% cream for facial melasma in dark-skinned patients, with 73% achieving good-to-excellent results versus 19%. Both treatments caused transient mild-to-moderate irritation.

Vehicle-controlled in vivo study: forearm skin treated with 20% glycolic acid lotion twice daily for 3 months showed significantly increased epidermal and dermal hyaluronic acid and type I collagen gene expression (mRNA) versus vehicle, indicating glycolic-acid-induced extracellular matrix remodeling of human skin.

Single-blind RCT (n=46, 12 weeks) in mild-to-moderate acne comparing salicylic acid 3% plus clindamycin with tretinoin 0.05% plus clindamycin: both significantly reduced inflammatory and non-inflammatory lesion counts; tretinoin acted faster (significant by week 2) but groups were comparable at 12 weeks, and both were well tolerated.