What is S-equol?

What you’ll learn: 

• What phytoestrogens are and why they matter for hormonal health 
• Why S-equol is unlike any other plant estrogen, and how it interacts with your body’s estrogen receptors 
• The benefits of S-equol backed by clinical research, and why most women in the US are missing out 

What are phytoestrogens? 

Phytoestrogens are naturally occurring compounds found in plant foods (”phyto” meaning “plant”). These plant compounds function like estrogen in the body, mimicking the body’s natural production of this important reproductive hormone. But they don’t just mimic estrogen, they modulate it. You can think of phytoestrogens like adaptogens for reproductive hormones. When estrogen levels are low (like in perimenopause and menopause), phytoestrogens will encourage estrogen receptor signaling. When estrogen is in high, these same compounds can block estrogen receptors to help buffer this excess. 

What is S-equol? 

S-equol is a unique phytoestrogen derived from soy. Unlike most plant estrogens, it isn’t found within foods itself - it’s produced in the body by your gut bacteria. When you eat soy-based food products, specific gut bacteria convert a compound within the soy called daidzein into S-equol. In other words, S-equol isn’t something you consume, it’s something your gut makes for you – provided you have the right bacteria to do so. 

How does S-equol work? 

Unlike regular phyotoestrogens, what makes S-equol unique is its selective interaction with estrogen receptors. Your body has two primary types of estrogen receptors - one type is expressed broadly throughout the body in adipose (fat) tissue, blood vessels, the brain, immune cells and the colon. The other is mostly found in reproductive tissues. 

S-equol binds strongly to estrogen receptors expressed in metabolically active tissues (adipose tissue, blood vessels, the brain, immune cells, and the colon) while binding only weakly to the estrogen receptors found in reproductive tissues. This selective binding profile is what makes S-equol so well-suited for women navigating midlife hormonal shifts. Rather than broadly activating estrogen signaling throughout the body, S-equol supports the tissues most impacted by declining estrogen - the ones where the metabolic and whole-body effects of hormonal change are felt most deeply. 

What are the benefits of S-equol? 

S-equol is a powerful phytogestrogen that only 20% of women naturally produce. While the body converts soy isoflavones to S-equol in the gut, few women in the US actually have the right microbiome to carry out this conversion. This is why many people may see little benefit from including soy products in the diet. 

These women are missing out on the benefits of this unique phytoestrogen, which has been well-studied in clinical trials for its metabolic and reproductive effects. Research shows that those who naturally produce S-equol have better health, including better blood sugar balance, vascular function, more favorable cholesterol levels, better cognition and lower rates of premenstrual syndrome (PMS). 

Interestingly, even women who already produce S-equol naturally saw additional benefits when they supplemented with it. One study demonstrated that these women experienced improved fat metabolism, reduced visceral fat (that fat around the organs that is metabolically active), improved cognitive health as well as fewer menopausal symptoms.

Clinical trials with S-Equol 

In numerous clinical trials conducted in normal healthy women, 10mg of S-equol per day has been identified as an effective dose. At this level, S-equol has been shown to support:

• Metabolic health and improved fat metabolism - supporting body composition 
• Menopausal symptom relief - reducing hot flashes 
• Blood sugar balance - supporting insulin sensitivity 
• Arterial health - promoting healthy cardiovascular markers