But unless you have a severe chemical sensitivity to hexane or pesticides, occasionally consuming small amounts is not worth getting bent out of shape over. The effects of soy and whey protein supplementation on acute hormonal reponses to resistance exercise in men. Soy contains phytoestrogens or “plant-estrogens,” which sounds bad but by out-competing estradiol, phytoestrogens can have a beneficial anti-estrogen effect in women of reproductive age. However, as I discussed in the section on allergies, soy lecithin contains very little soy protein, and lecithin from some sources contains no detectable protein at all. Chemical Cuisine. Further, it could interact with the drug Diclofenac and serum cortisol levels. (2011). (15) Interestingly, none of the soy lecithin they tested contained genistein, which is the predominant phytoestrogen in soy. Luckily, you can derive all the benefits of phosphatidylcholine supplementation just by increasing your consumption of choline-rich foods like egg yolks and liver. The hair loss could be caused by the estrogenic activity of the lecithin. 2 DAYS ATE CANDY WITH MILK… GOT SOME BACK BUMPS. Mouthwash and toothpaste contain soy.