Dioscorea Japonica Root Extract

Evidence by route

About this ingredient

Dioscorea Japonica Root Extract is derived from the rhizome of Japanese yam Dioscorea japonica. Used as a tonic in traditional Eastern medicine; in modern cosmetics – as a source of phytosterols and diosgenin. Composition. Saponins (diosgenin), phytosterols, amino acids, allantoin, polysaccharides. Diosgenin in the pharmaceutical industry serves as raw material for synthesizing steroid hormones (progesterone, cortisone). Mechanism. Manufacturers market the extract as a 'natural hormone-like ingredient' – hinting at estrogen-like activity for mature skin. On real human skin diosgenin isn't converted into active hormones (17β-HSD enzyme in skin doesn't work in that direction). The actual effect is most likely humectant and nourishing via polysaccharides and amino acids. Where applied. Anti-aging serums and creams from Asian and niche European manufacturers, menopausal skin products with 'phytoestrogens' marketing. In Spain – niche Japanese and Korean lines, specialized mature-skin products in cosmetology clinics. Evidence base. No direct clinical RCTs on topical use confirming an estrogen-like skin effect. Marketing claims of 'natural hormone replacement' are unfounded and potentially misleading for menopausal patients. Safety. CIR has not issued a direct evaluation. By the plant extract profile – low irritation and allergy risk. Systemic absorption through intact skin is low. Pregnancy and lactation – with caution. Plants with potential phytoestrogenic activity are avoided in pregnancy as a precaution. Best suited to: mature non-sensitive skin within multi-component formulas. Not an alternative to systemic hormone replacement therapy in menopause – this is a marketing ingredient.

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