After years of using it for liver protection while on cycle and PCT some people are all of a sudden saying it may be detrimental to gaining muscle. NAC has been one of the primary go to ingredients for AAS and PH cycles for 15 years and some are going to such an extreme - acting like you can't build muscle on it like all the years of people gaining off AAS and ph's is just in people's heads. I find it ridiculous for 3 reasons - 1) If you don't want to take antioxidants around your workout time, that's really simple - take it at a different time of the day. 2) People spend so much time nit picking if something may be detrimental yet to see even a minuscule lack of progress from it would mean that a person had everything right in their diet and training and then the addition of that may hold someone back when the reality is that 99.9% of people don't have everything perfect with their diet and training. 3) This ironically and conveniently happens when NAC pricing just happens to go up (and the exact same thing happened with Milk Thistle a few years ago when the pricing went up and when it came back down companies stopped talking about it). Oh and a nice 4th, NAC has been researched to help prevent muscle loss in the elderly and also in people fasting.