i havent really done much research into tcf-1 yet. ill look into it today. to be honest (i wasnt going to bring this up) i ran the trs stack maybe 6-7 months ago by itself to get a little boost as i suffer from low T levels. unfortunately, i didnt notice very much from it (other than highly elevated LH and prolactin levels; my bloods confirmed this). i ended up with a case of gyno, which resolved itself in a matter of months. I think the gyno was due to the SA which is why im weary of purchasing it again. my friend who also ran the SA ended up with gyno as well.