Name Ingredients:
Soy isoflavones are naturally occurring compounds found in soybeans and other soy products. They are a type of phytoestrogen, similar in structure to the female hormone estrogen. Soy isoflavones have been suggested to benefit hair health by potentially stimulating hair growth, preventing hair loss, and promoting thicker, stronger hair.
Key insights:
- The in vivo (in animals) data suggests that injection of genistein (a soy isoflavone) into mice with spontaneous alopecia areata can increase resistance to the onset of hair loss. By the end of the study, four of 10 mice injected with genistein developed alopecia areata, whereas 9 out of 10 of the controls developed it.
- A case series conducted on 354 Taiwanese males with androgenic alopecia (AGA) found that frequent (3 days per week) was associated with a 77% decrease in the risk of AGA.
- Another study was conducted in which a nutritional supplement containing several ingredients, including soy isoflavones, was given to 10 adults with AGA. While this resulted in significant improvements in hair counts, we cannot say whether this was due to soy isoflavones, as many other ingredients may have had an effect.
- The current literature supports the safety of soy isoflavones as typically consumed in diets based on human studies and toxicologic investigations.
- Our experience tracking members: soy isoflavones are not enough by themselves to improve hair loss outcomes.
Additional links:
- Soy Isoflavones: Evidence Quality (Rubric)
- Dietary soy oil content and soy-derived phytoestrogen genistein increase resistance to alopecia areata onset in C3H/HeJ mice
- Androgenic alopecia is associated with less dietary soy, lower [corrected] blood vanadium and rs1160312 1 polymorphism in Taiwanese communities
- Soy Isoflavones: A Safety Review