IngredientStudied forEvidence in shortUsual form
Astaxanthin Skin moisture; eye comfort after screen work Mixed for skin moisture, no effect on wrinkles; eye trials often tested combinations Soft capsule (oil-soluble, light-sensitive)
Ceramide Skin hydration and barrier function Small trials, often industry-linked, show a real but modest hydration effect Capsule, tablet, drink
Collagen peptide Skin hydration and elasticity Several meta-analyses positive; a 2025 analysis found the effect only in industry-funded trials Powder, drink, jelly (gram-level dose)
Elastin peptide Skin elasticity and hydration Small trials; a 12-week placebo-controlled study and supporting cell research Tablet, capsule
Evening primrose oil Skin barrier and comfort measures A 2013 Cochrane review of 27 trials found no benefit; individual trial results are mixed Soft capsule
Glutathione Skin brightness (purified form restricted as a food ingredient in Japan) Not applicable to purified glutathione as a declared food ingredient in Japan Purified form not permitted in foods in Japan; yeast-based route only
Hyaluronic acid Skin moisture and elasticity A 2025 meta-analysis of 7 small trials positive; mostly Asian participants, often industry-funded Capsule, tablet, drink
L-cystine Hair density and skin/hair keratin support Small trials of L-cystine combined with other nutrients; not tested alone Tablet, capsule
Lycopene Skin response to UV exposure Small trials positive; short, and results include molecular markers as well as visible skin measures Soft capsule (oil-soluble)
Pine bark extract Skin pigmentation and photoaging signs Small trials, one open-label and industry-funded; positive but not independently replicated at scale Tablet, capsule
Placenta extract Skin hydration Thin: a few small, short, often industry-funded trials of animal-derived extract Tablet, capsule, drink
Sea buckthorn oil Tear film and eye comfort in small randomised trials Mixed results across two trials in the same population; skin-specific human evidence is limited Softgel, oil blend
Tranexamic acid Skin pigmentation (medicine in Japan, not a food ingredient) Not applicable — not permitted as a food ingredient in Japan Not permitted in foods in Japan