Function

• Products for the skin and for unwanted hair have been developed that contain hydrolyzed soy protein, which slows down hair growth. Applying these products to your face will reportedly minimize a mustache and other facial hair that you would rather not have. Applying them to your legs slows down hair growth in that area, explains the Cosmetics & Toiletries website.
  
  

Application

• Mindbodyspiritjournal.com reports that a study was done involving applying soy milk patches to unwanted body hair. The outcome was that the soy patches reduced the size of the follicle and hair shaft as well as stunted hair growth on the legs and stripped the hair of its color.
  
  

Types

• When soy milk was bolstered with a bit of soy isoflavone solution, the results were even faster and more noticeable. Those participants in the study reported that the hair treated with soy was thinner and softer.
  
  

Effects

• According to a report delivered by M. Seiberg, J-C Liu, L. Babiarz, E. Sharlow and S. Sharpiro, serine protease inhibitors and soybean extracts can alter skin pigmentation and may be an alternative to skin lightening; however, in addition, the rate of hair growth was also found to be slowed, and the appearance of hair and the size of the hair shaft and follicles were changed. Soy milk does impact hair growth because it decreases hair shaft dimensions, according to the report.
  
  

On the Other Hand ...

• Eating soy protein reportedly stimulates hair growth and reinforces hair, making it strong, notes Holisticonline.com. Soy isoflavone appears to regulate bad cholesterol, reducing it; this is beneficial because bad cholesterol produces enzyme 5 alpha reductase, which transforms the hormone testosterone into DHT, dihydrotestosterone, which results in hair loss.