Can I take these supplements without gynecomastia returning?

It is hard to predict what supplements will affect some men and not others as far as developing breasts. Estrogen in plant form is not the same as human estrogen, whereas estrogen from cows is the same as human estrogen. Some protein drinks are made with whey which are derived from milk and protein bars can be worse as they may be made from whey and flax seeds, and flax seeds are higher in phytoestrogens by 265% over soy. Men who are susceptible to breast growth may want to consider this. Good luck.

Thank you for your question. It is a difficult one to answer as their are several theories around this which means no one answer is correct ! Essentially Casein and whey protein are extracted from cow milk. Now there is an opinion that in modern farming, cows are milked several hundred times a year and are kept pregnant during this time. During pregnancy the cow endocrine system produces oestrogen and this hormone gets into the milk. Milk from a cow which is in the late stage of pregnancy contains approximately 33 times more estrogen than milk from a cow which is not pregnant. Therefore, the hypothesis is that casein and whey protein powder contain oestrogen which may increase the chances of developing gynecomastia. Others feel that oestrogen levels in protein powder are too low to have physiological effect on human body. So, casein and whey protein powder may be related to gynecomastia but it depends on many circumstances including age and hormonal sensitivity.WIth other amino acid and protein supplements it is really the whey content that is the issue in my opinion and therefore I think it would need to be considered. I hope this is of some help ! BW