Regulatory Status
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Safety Data
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Toxicological Studies
1 study endpoint found for Daidzein. NOAEL (No Observed Adverse Effect Level) values are used to calculate the Margin of Safety per SCCS methodology.
| Endpoint | Value | Route | Species | Study Type | Source |
|---|---|---|---|---|---|
| NOAEL | =19 mg/kg/day | oral | rat | reproductive | SCCS |
SCCS NOAEL Values
NOAEL/LOAEL values cited in official SCCS opinions for Daidzein.
| NOAEL | LOAEL | Route | Species | Study | DA% (SCCS) | Opinion |
|---|---|---|---|---|---|---|
| 50 mg/kg/day | 150 mg/kg/day | Oral | Rat | Developmental/reproductive (Gestational/neonatal period) | 20 | SCCS/1641/22 (2022) |
Expert Verdict
Daidzein is the principal soy isoflavone precursor to equol, the metabolite responsible for much of soy's phytoestrogenic activity. Clinical studies of combined soy isoflavones (genistein + daidzein) over 12–24 weeks showed improvements in skin dryness, thickness, wrinkles, hyaluronic acid levels, and collagen I/III in postmenopausal women. Individual topical data for daidzein alone is less established than genistein. Claim compliance is the primary formulation risk — hormonal mechanism claims trigger drug classification in both EU and US.
Regulatory Flags
Frequently Asked Questions
Is Daidzein safe in cosmetics?
Daidzein is the principal soy isoflavone precursor to equol, the metabolite responsible for much of soy's phytoestrogenic activity. Clinical studies of combined soy isoflavones (genistein + daidzein) over 12–24 weeks showed improvements in skin dryness, thickness, wrinkles, hyaluronic acid levels, and collagen I/III in postmenopausal women. Individual topical data for daidzein alone is less established than genistein. Claim compliance is the primary formulation risk — hormonal mechanism claims trigger drug classification in both EU and US. The EU classifies Daidzein as "permitted". Safety rating: GOOD. 1 toxicological study endpoint(s) are available in our database.
Is Daidzein allowed in the EU?
Daidzein EU regulatory status: permitted. This is based on EU Regulation 1223/2009 and its amendments.
What does Daidzein do in cosmetics?
Daidzein functions as: Skin-conditioning agent, phytoestrogen-class active (ERβ agonist; soy isoflavone; precursor to equol via microbial metabolism; collagen and hyaluronic acid support). It is classified as a Active Ingredient in our database. CAS number: 486-66-8.
What is the Margin of Safety for Daidzein?
adequate The Margin of Safety (MoS) is calculated using SCCS methodology. A MoS above 100 is generally considered safe. Use the MoS Calculator tool to calculate MoS for your specific formulation and product category.
What is the NOAEL for Daidzein?
The NOAEL (No Observed Adverse Effect Level) for Daidzein is =19 mg/kg/day based on a reproductive study via oral route in rat. Source: SCCS.
Compliance Tools
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