What is equol?
S-Equol, also known as 4′,7-isoflavandiol, (3S)-Isoflavan-4,7′-diol, and (3S)-3-(4-Hydroxyphenyl)-3,4-dihydro-2H-1-benzopyran-7-ol, is a highly bioactive isoflavan naturally formed when specific gut bacteria metabolize the soy isoflavone daidzein. Due to the presence of a chiral center at the C-3 position, equol exists in two enantiomers, S-equol and R-equol, but only the S-form is produced in humans and animals. S-equol closely resembles estradiol in molecular structure and selectively binds to estrogen receptor beta, which gives it unique physiological effects related to hormonal balance, menopausal support, and healthy aging.
Not everyone can naturally produce S-equol. Research shows that only 40 to 70 percent of East Asians and 20 to 30 percent of Western populations are equol producers, meaning many people may not receive the full benefits of soy isoflavones through diet alone. Supplemental S-equol offers a consistent, bioavailable, and clinically relevant form of this metabolite that avoids overstimulation of estrogen receptor alpha and provides a favorable safety profile. Its selectivity for ERβ makes it an ideal ingredient for women’s health, skin support, cognitive wellness, and bone maintenance formulas.
Cima Science manufactures high-purity S-equol through a controlled fermentation process that yields more than 99 percent S-form content with excellent stability and consistency. As a leading S-equol producer in China, Cima Science also offers comprehensive OEM services, including S-equol capsules, tablets, custom blends, and full formula development. From bulk raw material supply to finished-product manufacturing, we support brands and nutraceutical companies seeking premium-quality S-equol ingredients tailored to their product goals.
s-equol VS SR-equol
Equol is the final and most biologically active metabolite of soy isoflavones. It exists in two isomeric forms, with S-equol being the natural isomer created by human intestinal flora. It is the only form synthesized from daidzein by gut bacteria, although only 20 to 35 percent of adults can produce it naturally. SR-equol, also known as (+/-)-EQUOL, contains a racemic mixture of S- and R-isomers. While SR-equol (CAS 94105-90-5) can be produced synthetically, only S-equol (CAS 531-95-3) shows strong physiological activity, superior receptor selectivity, better bioavailability, and clear health benefits. For dietary supplements, women’s health products, and anti-aging formulas, S-equol is considered the superior and preferred choice due to its higher potency and relevance to human biology.
| Item | S-Equol | SR-Equol (±-Equol) |
|---|---|---|
| CAS Number | 531-95-3 | 94105-90-5 |
| Other Names | 4′,7-isoflavandiol; (3S)-Isoflavan-4,7′-diol; Natural equol isomer | (+/-)-Equol; Racemic equol; Mixture of S-equol and R-equol |
| Molecular Formula | C15H14O3 | C15H14O3 |
| Molecular Weight | 242.27 g/mol | 242.27 g/mol |
| Appearance | White to off-white crystalline powder | White to slightly off-white powder |
| Natural Food Sources | Not found directly in foods; produced only by gut bacteria from daidzein | Not naturally present in foods; synthetic production only |
| Origin | Naturally produced in humans with equol-producing microbiota | Synthetic racemic blend of both isomers |
| Biological Form | Pure S-isomer; biologically active | Mixture of active S-isomer and less active R-isomer |
| Purity (commercial) | 98 to 99 percent S-isomer | Typically 50 percent S + 50 percent R |
| Bioavailability | High; matches human metabolic pathways | Moderate; diluted activity due to R-isomer |
| Potency | Strong affinity for ERβ and the dominant active form | Lower potency because R-equol has weak or negligible receptor activity |
| Mechanism Strength | Highly selective for estrogen receptor beta | Weaker and less selective due to racemic mixture |
| Half Life | About 7 to 10 hours | Shorter effective half life because of inactive R portion |
| Recommended Dosage | 5 to 20 mg per day for supplements | Higher dose needed to achieve similar benefits |
| Stability | Good stability in powder form | Slightly less stable due to mixture of two isomers |
| Specifications Available | ≥98 percent, ≥99 percent, fermentation based | 50 percent S-form, synthetic origin |
| Main Benefits | Menopausal comfort, skin support, hormonal balance, bone health, cognitive wellness | General isoflavan support with weaker estrogen receptor activity |
| Popularity in Supplements | Very high; preferred active ingredient for women’s health products | Low; rarely used due to weaker clinical relevance |
| Pricing (bulk) | Medium to high depending on purity, typically premium due to natural S-form | Low to medium; economical but less effective |
| Ideal Use | Premium nutraceuticals, women’s health formulas, anti-aging supplements | Research, cost-sensitive formulations, or experimental use |
S-equol vs soy isoflavones
s-equol Specifications
Cima Science’s S-Equol powder is manufactured to meet strict internal and international quality standards. Each batch undergoes comprehensive testing to confirm its identity, purity, safety, and stability. The COA demonstrates that our S-Equol has a purity greater than 99 percent, excellent optical rotation, low solvent residues, and extremely low levels of heavy metals and microbiological contaminants. All specifications fully comply with enterprise standards and third-party testing requirements, ensuring that the final ingredient is high quality, safe, and suitable for premium nutraceutical formulations.
| Testing Item | Specification | Result |
|---|---|---|
| Appearance | White powder | Conforms |
| Loss on Drying | ≤ 1.0% | 0.73% |
| Melting Point | 189–190°C | 189°C |
| Optical Rotation | [α]D < (−)21° (c = 5.0 g/L, ethanol) | −23.3° |
| Residual Solvent (Ethanol) | < 200 ppm | 37.8 ppm |
| Heavy Metals | ≤ 10 ppm | Conforms |
| Lead (Pb) | ≤ 1.0 ppm | Conforms |
| Arsenic (As) | ≤ 1.0 ppm | Conforms |
| Cadmium (Cd) | ≤ 1.0 ppm | Conforms |
| Mercury (Hg) | ≤ 1.0 ppm | Conforms |
| Total Plate Count | ≤ 1000 cfu/g | Conforms |
| Coliforms | ≤ 100 cfu/g | Conforms |
| Salmonella | Not detected | Not detected |
| Mold & Yeast | ≤ 100 cfu/g | Conforms |
| Assay (Purity) | ≥ 99.0% | 99.8% |
s-equol Benefits
S-equol is widely recognized as the most bioactive metabolite of soy isoflavones and offers targeted health benefits due to its strong affinity for estrogen receptor beta. Unlike soy isoflavones, S-equol delivers consistent physiological effects that are not dependent on an individual’s gut microbiota. It is frequently used in women’s health supplements, healthy aging formulas, and specialized products supporting hormonal balance, skin health, and metabolic wellness. Emerging research also highlights unique advantages related to S-equol hair loss support and S-equol weight loss, making it a versatile ingredient for modern nutraceutical formulations.
- Supports menopausal comfort, including relief from hot flashes and night sweats
- Helps balance estrogen activity by selectively activating ERβ without overstimulating ERα
- Promotes S-equol hair loss support by helping reduce DHT-related effects on hair follicles
- Contributes to S-equol weight loss by assisting healthy metabolism and managing hormonal fluctuations
- Enhances skin health through improved elasticity, hydration, and collagen protection
- Supports bone strength and density by influencing estrogen pathways linked to bone turnover
- Contributes to emotional balance and cognitive well-being, especially during menopause or hormonal transition
- Provides cardiovascular support through its favorable effects on lipid metabolism
- Offers higher potency than soy isoflavones, delivering stronger benefits at significantly lower dosages
- Suitable for individuals who cannot naturally produce S-equol due to microbiome variations
S-equol Manufacturing Process
Cima Science produces high-purity S-Equol 99% powder through a controlled fermentation and purification system designed to match the natural S-equol produced in the human body. Our process uses non-GMO microbial strains, advanced bioconversion technology, and strict quality control to ensure consistent purity, safety, and bioactivity. Every batch meets international standards and passes third-party testing, making it ideal for premium nutraceutical formulations.
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Raw material selection and preparation
High-quality soy germ extract rich in daidzein is selected, tested, and prepared under strict quality standards. -
Proprietary fermentation with selected microbial strains
Non-GMO probiotic strains convert daidzein into intermediate metabolites and finally into natural S-equol. -
Bioconversion optimization
Fermentation conditions such as pH, temperature, oxygen, and nutrient supply are optimized to maximize S-equol yield and purity. -
Multi-step purification and isolation
Filtration, separation, and chromatography are used to isolate high-purity S-equol with minimal impurities. -
Concentration, drying, and powder formation
The purified S-equol is concentrated and dried using low-temperature spray or vacuum drying to create a stable, free-flowing powder. -
Quality control and third-party testing
Each batch is tested by HPLC for ≥99 percent purity and evaluated for heavy metals, microbial safety, residual solvents, and stability. -
Packaging and global export
Finished S-equol 99% powder is packed in food-grade bags and drums and shipped worldwide in compliance with international standards.
Where to buy S-equol bulk powder?
If you are looking for a reliable source of bulk S-equol powder for your equol supplement brand or formulation, Cima Science is your ideal manufacturing partner. As a source factory with no middlemen and no price markups, we offer high-quality, high-purity S-equol at competitive wholesale pricing. Our S-equol is produced from natural plant sources such as black beans and manufactured using patented fermentation technology that ensures the ingredient is 100% naturally derived. Every batch is authenticated through C14 analysis to verify its natural origin and tested by NMR and HPLC to confirm exceptional quality and an S-configuration purity greater than 99%.
Cima Science provides stable manufacturing, consistent quality, and purity levels up to 98 to 99 percent, making our S-equol suitable for premium nutraceutical products. We offer free samples, flexible cooperation models, and multiple supply options to meet the needs of supplement brands, distributors, and formula developers worldwide. With a streamlined production process, high standards, and verified authenticity, Cima Science is one of the best places to buy bulk S-equol powder with confidence.
