active

Genistein

INCI: GENISTEIN
CAS 446-72-0 EC 207-174-9
5,7-dihydroxy-3-(4-hydroxyphenyl)-4-benzopyrone
Limited Data
Insufficient safety data available. Consider enriching this ingredient.
Details

Description

5,7-dihydroxy-3-(4-hydroxyphenyl)-4-benzopyrone

Purpose

Function

5-alpha-reductase inhibitor; phytoestrogen; ER modulator; anti-androgenic; antioxidant; hair-growth active
Profile

Properties

Silicone
Silicone free
Compliance

Regulatory Status

EU
Permitted
Safety
GOOD
US
Permitted
EU Max Concentration0.007%
Absorptionmoderate
Sensitizationnone
MoSadequate
NOAEL0.3 mg/kg
ConcernLow
Flags
hair-growth-active5ar-inhibitorphytoestrogenanti-androgenicsoy-derivedclaim-sensitivecosmetic-classifiedendocrine_disruptor
Verdict

Genistein, the principal isoflavone from soy, operates through dual mechanisms in hair loss: 5α-reductase inhibition (reducing DHT) and estrogen receptor modulation (phytoestrogenic effect providing follicle-protective benefits). Particularly relevant to postmenopausal FPHL where estrogen decline activates DHT-mediated follicle miniaturization. Evidence is primarily in vitro and limited human studies; FPHL-specific large RCTs are lacking. SCCS calculated adequate margin of safety (≥100) at 0.007%. Phytoestrogenic activity requires careful claim positioning in EU cosmetics to avoid medicinal product classification. GOOD safety profile at cosmetic use levels.

US Note

Permitted cosmetic active. No OTC drug monograph. Phytoestrogenic mechanism means claim language requires care to avoid drug classification.

Assessment

Ratings

Comedogenic0/5
LowHigh
Irritancy0/5
LowHigh
Reference

Identifiers

CAS Number
446-72-0
EC Number
207-174-9
INCI
GENISTEIN
Category
active
Updated
Apr 23, 2026