Ingredients · Scientific analysis
Fermented rice benefits for the skin
A literature review on Korean cosmetics' most-studied ingredient — and one of the oldest used in routine.
The four key actives
Niacinamide
Form · vitamin B3
Regulates melanin production, strengthens skin barrier, reduces redness.
Average concentration in fermented rice: 0.8 to 1.2%
Kojic acid
Form · fermentation by-product
Inhibits tyrosinase, brightens hyperpigmentation spots, unifies complexion.
Average concentration: 0.05 to 0.3%
γ-Oryzanol
Form · rice bran phenolic compound
Powerful antioxidant, protects from oxidative stress, anti-aging.
Average concentration: 1.5 to 3%
Vitamin E
Form · tocopherols and tocotrienols
Nourishes, hydrates, protects cell membrane, anti-inflammatory.
Average concentration: 0.5 to 1%
Why ferment, scientifically?
Raw rice is a starch from which the skin extracts almost nothing: molecules are too large to penetrate the stratum corneum. Fermentation, conducted for 60 to 90 days by lactic bacteria and natural yeasts, performs three transformations.
Enzymatic hydrolysis — long proteins break into short peptides, capable of crossing the stratum corneum.
Secondary active synthesis — microorganisms produce niacinamide, kojic acid, essential amino acids that don't exist in raw rice.
Gentle acidification — the pH drops to 4.5-5, exactly the natural pH of skin. No irritation, optimal penetration.
Measured effects on skin
Three major clinical studies (Yonsei University 2018, Seoul National University 2021, KAERI 2023) measured fermented rice's topical effect on panels of 30 to 60 subjects. Results converge.
- Corneal hydration: +52 to +68% at 14 days, measured by corneometer.
- Roughness reduction: −22 to −34% at 28 days.
- Pigment spot reduction: −18% at 56 days.
- Sebum production: regulated down on combination skin (−15%), stable on dry skin.
How to use it correctly
Fermented rice is compatible with nearly all other cosmetic actives — that's precisely what makes it K-beauty's universal base. A few rules nonetheless:
- Apply as first water layer, on clean and warm skin.
- Space by 2-3 minutes the layers of strong actives (salicylic acid, retinol).
- Compatible morning and evening. No additional SPF required but advised during the day.
- Storage: 3 months after opening, away from light. A brown essence yellows as it ages — that's normal, it's polyphenol oxidation.