S-Equol
CAS 531-95-3
Purity≥98.0%
S-equol material for women's-health and isoflavone research
For B2B ingredient sourcing, request the specification, batch COA, sample, packaging and lead-time confirmation. Explore healthy-aging ingredients.
Request separate chemical-purity and optical-purity results.
Key Specifications
| Product Positioning | S-equol material for women's-health and isoflavone research |
| Application Scenarios | women's-health nutrition formulation · isoflavone metabolism research · skin-care formulation evaluation |
| CAS Number | 531-95-3 |
| Purity | ≥98.0% |
| Molecular Formula | C₁₅H₁₄O₃ |
| Molecular Weight | 242.27 g/mol |
| Appearance | White to off-white crystalline powder |
| Solubility | Slightly soluble in water; soluble in ethanol |
| Storage | Room temperature, protect from light |
| Shelf Life | 24 months |
Procurement & delivery
Supply details confirmed by intended use, volume and target market
S-Equol (CAS 531-95-3) is a non-steroidal isoflavandiol phytoestrogen with molecular formula C15H14O3 and molecular weight 242.27 g/mol. In nature it forms as a gut-microbial metabolite of the soy isoflavone daidzein, generated when specific intestinal bacteria reduce daidzein through dihydrodaidzein and tetrahydrodaidzein intermediates; however, only an estimated 30-50% of people carry the gut flora needed to produce it naturally ("equol producers"). Because this conversion cannot be relied upon through diet alone, commercial bulk S-equol is generally manufactured by microbial biotransformation: engineered bacteria carrying the natural equol-producing enzyme pathway convert plant-derived daidzein into the single, non-racemic S-enantiomer under controlled fermentation conditions, followed by extraction, purification, and crystallization to consistent nutraceutical-grade purity.
≥99% Optical Purity
HPLC purity ≥99% with a single, verified S-enantiomer (non-racemic), delivering the isoflavandiol form with high selectivity for ERβ rather than a mixed R/S product.
Controlled Biocatalytic Production
Produced via engineered microbial biotransformation of plant-derived daidzein rather than chemical racemic synthesis, giving tighter batch-to-batch consistency and a documented process route.
Fine Crystalline Powder Form
Supplied as a white to off-white crystalline powder with controlled particle size, supporting consistent dissolution and ease of handling in downstream formulation.
Rigorous Contaminant Screening
Every batch is screened for heavy metals (Pb, As, Cd, Hg) and microbial limits (total plate count, yeast/mold, E. coli, Salmonella) to support food- and cosmetic-grade use.
Flexible Bulk & OEM Supply
Available in flexible bulk quantities with OEM/private-label documentation support (COA, MSDS, specification sheets) for supplement, skincare, and finished-dose manufacturers.
Test items, specifications and batch results are shown here; request the formal COA through the card below.
Batch No.
PGSEQ-260716
Test date
2026-07-30
Specification
In-house
Pack size
1 kg/bag
Storage
Room temperature, protect from light
Conclusion
Conforms
| Test Item | Specification | Result |
|---|---|---|
| Appearance | White to off-white crystalline powder | White crystal powder |
| Identification | IR spectrum concordant with reference | Complies |
| Solution clarity and color | Clear and colorless | Complies |
| Purity | ≥98% | 99.9% |
| Assay (dry basis) | ≥98% | 99.9% |
| Loss on drying | ≤1.0% | 0.04% |
| Ethanol residue | ≤200 ppm | 76 ppm |
| Melting point | 185–195℃ | 189℃ |
| Specific optical rotation | [α]D < −21° | −22° |
| Lead (Pb) | ≤1.0 ppm | Not detected |
| Mercury (Hg) | ≤1.0 ppm | Not detected |
| Cadmium (Cd) | ≤1.0 ppm | Not detected |
| Arsenic (As) | ≤1.0 ppm | Not detected |
| Total plate count | ≤1000 CFU/g | <10 CFU/g |
| Yeast and mold | ≤100 CFU/g | <10 CFU/g |
| Coliforms | Not detected | <0.3 MPN/g |
| Staphylococcus aureus | Not detected | Not detected |
| Salmonella | Not detected | Not detected |
This page shows a batch-data summary only. No direct COA file link is provided; request the signed document through the form below.
Hard capsules
Powders
Softgels
Tablets
Sublingual tablets
Oral dissolving films
S-Equol can be evaluated in women’s-health formulas that also address bone-nutrition needs. Use calcium and vitamin D only as formulation components with independent nutritional justification; do not claim a proven S-Equol synergy.
Evidence: Indirect evidence: an EMAS position statement cites an isoflavone + calcium + vitamin D + inulin trial; the study was not a direct S-Equol combination trial.Source
Literature-Supported Research Directions
In a randomized, double-blind, placebo-controlled study of postmenopausal equol non-producers, 12 weeks of 10 mg/day natural S-equol was associated with reductions in hot-flush frequency and neck or shoulder muscle stiffness.
Citation: Takeshi Aso et al., Journal of Women's Health (2012) 21(1): 92–100. DOI: 10.1089/jwh.2011.2753. PMID: 21992596.View source
A small randomized placebo-controlled study observed reduced crow’s-feet wrinkle area after 12 weeks of 10 or 30 mg/day natural S-equol in postmenopausal women; the finding is specific to the studied population and oral supplementation context.
Citation: Oyama et al., Menopause (2012): natural S-equol and skin aging in postmenopausal women.View source
In a one-year randomized controlled study, 10 mg/day S-equol was associated with reduced urinary deoxypyridinoline and prevention of whole-body bone mineral density decline, supporting further research in women’s health and bone metabolism.
Citation: Tousen et al., Menopause (2011): natural S-equol and bone resorption in postmenopausal women.View source
Note: For ingredient R&D and scientific information; findings depend on model, dose, formulation and population and do not constitute a treatment claim or efficacy guarantee.
Lead Time
3–5business days
Standard products are generally in stock; confirm the exact lead time with us.
Minimum Order
100 g
Samples, pilot trials, and commercial volumes are supported.
Foil Pouch
Sealed, moisture-protective inner packaging
Fiber Drum
Standard outer packaging for bulk transport
Bulk Shipping
Palletized and stretch-wrapped for protection
Ambient storage: foil pouch + fiber drum; temperature controlled: foil pouch + insulated box/carton. Confirm by product.
Custom packaging: Custom foil bags or HDPE drums, GMP label printing, and export documentation are available. Contact us for a quote.Images are packaging illustrations.
Certifications
Substrate Preparation
Food-grade daidzein, extracted and purified from soybean isoflavone concentrate, is prepared as the starting substrate for bioconversion.
Biocatalyst Strain Fermentation
An engineered microorganism strain carrying the natural equol-producing enzyme cassette (originally identified in equol-producing gut bacteria) is fermented under controlled temperature, pH, and aeration to generate active biocatalyst biomass.
Enzymatic Bioconversion
Daidzein is fed into the bioreactor and sequentially reduced through dihydrodaidzein and tetrahydrodaidzein intermediates by the enzyme cascade, with cofactor regeneration maintained, to yield exclusively the S-configuration equol.
Biomass Removal / Clarification
The bioconversion broth is centrifuged and/or microfiltered to remove residual cell biomass, yielding a clarified S-equol-containing solution.
Extraction
S-equol is extracted from the clarified solution using food-grade organic solvent (e.g., ethyl acetate), followed by solvent recovery and concentration.
Crystallization & Recrystallization
The concentrate undergoes controlled crystallization and recrystallization to remove residual daidzein, intermediates, and process impurities, raising chemical and chiral purity.
Drying & Micronization
Crystals are vacuum-dried to remove residual solvent and moisture, then milled/sieved to a controlled fine powder particle size.
QC Testing & Packaging
Each batch is tested for assay, chiral purity, heavy metals, and microbial limits, then packed in sealed, moisture-protective containers under GMP-aligned conditions.
Purity and identity are determined by reversed-phase HPLC with UV detection, quantified against a certified S-equol reference standard; chiral HPLC or polarimetry is used separately to confirm the S-configuration is non-racemic. Buyers should request the batch-specific Certificate of Analysis and, for chirality-sensitive applications, ask for the chiral purity data (not just total isoflavandiol content) to confirm the material is not an R/S mixture.
S-equol is slightly soluble in water but readily soluble in ethanol and most polar organic solvents, a profile typical of isoflavandiol-class phytoestrogens. For oral soft-gel or tablet formulations, it is commonly pre-dissolved or co-processed with edible oils, lecithin, or cyclodextrin-based carriers to improve dispersibility and bioavailability; for topical creams, serums, and emulsions, it is typically incorporated into the oil phase or solubilized with an ethanol/glycol co-solvent system before emulsification. Formulators should confirm compatibility and target concentration with small-scale trials before scale-up.
Each batch is tested by HPLC against a certified reference standard, with chiral analysis confirming the material is a single non-racemic S-enantiomer rather than an R/S mixture. A batch-specific COA is provided with every shipment.
It is produced by microbial biotransformation: an engineered bacterial strain carrying the natural equol-producing enzyme pathway converts plant-derived daidzein (from soy isoflavone extract) into the single S-configuration product, followed by extraction and purification. This differs from chemical racemic synthesis in that it avoids downstream chiral resolution.
S-equol is only slightly soluble in water but soluble in ethanol; it is commonly solubilized with oils, lecithin, or cyclodextrin carriers for oral dosage forms, or dissolved in an ethanol/glycol system for topical formulations.
Yes, small trial samples are available for formulation testing and internal quality verification prior to committing to a bulk purchase order.
Yes, samples and shipments can be submitted to an accredited third-party laboratory of the buyer's choice for independent verification of purity, chirality, heavy metals, and microbial limits.
Yes, we support OEM and private-label programs for soft-gels, tablets, and topical formulations, including formulation guidance and full technical documentation (COA, MSDS, specification sheet, TDS).
Standard packaging is in sealed, moisture- and light-protective containers (e.g., aluminum foil bags or drums with double-layer liners); custom packaging sizes and formats can be arranged for larger orders.
MOQ varies by application volume and packaging format; please contact our sales team with your target quantity, purity requirement, and intended use for a tailored quotation and lead-time estimate.
Documents are subject to product and batch availability; third-party reports are provided only when applicable.
Quality documents
The specification sheet defines acceptance limits. The COA shows actual batch results, which may vary by batch. Third-party reports are provided only for products or batches that have been independently tested.
Stable acceptance criteria · Available on request
Actual test data · Issued with each shipment
Independent test record · Available by product/batch
Technical Resources
Learn how S-Equol differs from Equol, why gut microbiota matters, and which chemical and optical-purity data bulk buyers should verify.
A sourcing guide to S-Equol identity, engineered-microorganism bioconversion, chemical and optical purity, batch documentation, and formulation review.
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