@Ty Vincent wow, thank you for the thorough response. The first thing I'll say is, I was a patient of Dr. Nichols for a few months a few years ago, and found him to be extremely egotistical and close-minded. That said, what has confused me is that a significant number of other very well known docs in the space are largely agreeing with him on the estrogen issue. I would never suggest you spend 4 hours watching that video, but if you want to see some his most specific arguments/viewpoints on estrogen, here's a 20-minute video clipped from that long lecture. This stuff is way over my head, so if that's something you decide to watch you'd probably have a good understanding of what his position is (and how he's trying to defend it). From what I can gather, he believes "estradiol is indirectly implicated in all the issues people associate with high estrogen," with the idea that norepinephrine and serotonin are directly implicated. In terms of what risk they say they are: Many of these docs are saying AI usage is inherently detrimental to vascular health, and increases risk of heart attack. A quote one of them recently wrote when someone suggested he was being arrogant in telling men not to use an AI when symptoms that look like high estrogen are present: "It's not arrogance, my friend... It's 25+ years of telling wives and kids their 50-year-old dad is dead of an MI, and then hearing uninformed influencers giving guys like you advice that I (and everyone else who takes care of heart disease) know is increasing the chance that something like that is going to happen to them as well." Follow up question: If the levels we need to benefit from TRT require estrogen (and potentially DHT) modulation, why is that? For example, a healthy guy with adequate testosterone naturally has never needed to modulate estrogen or DHT, so why are we having to in order to achieve and maintain the levels required to get the benefits when using exogenous test? I guess what I'm saying is: If we are taking test levels so high via TRT that we have to then manage estrogen and DHT - but this isn't required in natural men with adequate testosterone - is this a sign that we are taking testosterone levels considerably higher than anyone could ever achieve naturally? And if so, why are we having to do that to get a positive result from treatment?

@Ty Vincent Appreciate the response. Honestly, what stood out to me about you after watching the first video I stumbled across was a very genuine desire to help people and the willingness to maintain an open mind to do that — so the quote you shared seems very fitting. Everything you're saying here makes sense. The idea that chemicals and other endocrine-disrupting agents are creating some kind of resistance at the receptor site also makes a lot of sense. I think I was hoping there was a way around needing an AI because I have built in a level of fear around them due the warnings some of these doctors have spoken about them - and as someone who's struggled with OCD, that kind of thing haunts you (especially when it's this "invisible" threat where they say "you could feel totally normal and have perfect blood work and then die of a heart attack at 50 because the AI wrecked your vascular health). But in the end, my goal is to feel my best as you noted, and to this point I haven't been able to get this TRT thing figured out in a way that's helped me do that. On that note, I do have another question - but it kind of diverts from the estrogen topic, so I'll ask it in a separate thread so that it stays better organized.