if you mean gyno than yes, it will make it worse. but only when you stop using it. while on it things will get better, or they should. nolva, a serm, will block estrogen at the receptor. but boosts serum estrogen levels, so you still need a AI to combat this. if you dont once you get off the nolva nothing is blocking E any more. and your serum E is high, you will mostly likely get rebound or the lump will slowly grow back.
letro & either prami or caber is your answer. prami/caber are both DA's, they will keep libido high while on letro. being on letro will suck a$$. no libido (unless you get prami/caber) no muscle gains, feel like total sh!t, joints kill, etc. but 2mg of letro for 2wks, than 1mg for 1wk, than .5mg for 1wk, than switch to aromasin should get rid of the gyno. letro needs to be tapered down or you will get reboud from that too as its so strong and over powering. switching to something OTC of lighter will allow you to get off an AI and not have any ill effects.
lookup chemical need, they are a sponsor. they have both letro/prami. go .25mg ED on the prami.
GL bro