Summary: Yes! It will increase estrogen and lower testosterone based on scientific research (see below).
We have been striving to stray away from the all-present soy additives in our food source by eating clean and researching our nutritional supplement ingredients. We’ve even compiled a list of Soy Free Protein Powders and Soy Free Vitamins.
Is Soy Lecithin Bad for Testosterone Levels?
We all know soy protein, soy flour and other soy products contain a multitude of phytoestrogens and phytosterols, which interfere with the bodies testosterone and estrogen levels. Namely by blocking testosterone receptors and binding with estrogen-receptor sites throughout the body. 
Meaning… it lowers your testosterone, and increases your estrogen levels.
What is soy lecithin? Its an emulsifier, meaning its the “glue” that keeps the cocoa and cocoa butter together so your candy bar doesn’t just fall apart. Emulsifiers have been in use for ages, however due to soy emerging as a cheap alternative ingredient in many foods in the past decade, it has been widely publicized as a miracle food and steadily added everywhere in our food.
The Soy Lecithin – Soy Protein Link
Ok… so we know to stay away from soy protein and soy flour… but what about soy lecithin?
Some tout it as being just as bad as soy protein, some say its phytosterol and phytoestrogen levels are so low it doesn’t matter.
Either way… soy lecithin is in everything! It is near impossible to cut it out of your diet unless you switch to a simple diet (hmm… possible future project?).
While I couldn’t find any concrete studies which specifically said “soy lecithin is as bad as soy protein”, I did find an interesting website which produced an independent test result of phytosterols in a leading brand of soy lecithin.
The test results from Microbac laboratories showed that the soy lecithin tested contained ~2,300 ug/g phytosterols. 
This means 0.23% of soy lecithin is phytosterols by weight.
When I searched for phytosterol levels in soy protein, I came across the Silk soymilk website, which touted the soy benefits of their product:
“A serving of Silk Heart Health provides .65 grams of phytosterols and 6.25 grams of soy protein” 
My Silk Almond Milk product from the fridge lists 1 cup as a serving size, so I’m assuming its the same for Silk Heart Health.
Assuming 245g soymilk / cup, this means phytosterols make up 0.2% of soymilk by weight…
So its true!!! Soy lecithin contains phytosterol levels just as potent as soymilk!
The question now is… exactly how much soy lecithin is put into our foods? FDA regulations only require ingredients be posted, not amounts of ingredients. If its a small amount, eating some soy lecithin here and there probably won’t hurt. However… take a look at your foods ingredients list. The typical American diet has soy lecithin in almost every meal. Day in and day out, these small quantities add up.
What should I do then about soy lecithin?
Keep a lookout for soy lecithin as an ingredient in your food’s ingredients list. Try to cut out the foods with soy lecithin listed as an ingredient. A much healthier alternative to soy lecithin is sunflower lecithin! (Actually when I checked my Silk Almond Milk’s ingredient list, I was surprised to see Silk did the responsible thing and used sunflower lecithin in place of its cheaper soy alternative).
We’ll be looking more into the soy culprit in the future. For now, I know I have another culprit to look out for while scanning ingredient lists!
It is relatively simple to cut out soy lecithin from our diets by eating whole foods such as meat, fruits, vegetables, nuts and berries, however when it comes to supplementing our diets with protein powders and vitamins, we are left with very few soy free alternatives. This is why we compiled a resource of Soy Free Protein Powders and Soy Free Vitamins.