Well, yes and no, correct?
Mesterolone provides the sexual, cognitive, and other benefits of DHT, so it does replace the DHT provided by testosterone in that regard.
However, it doesn't aromatize to estrogen at all, so anyone taking only mesterolone for TRT would be missing out on all the positive benefits (as well as the negative effects) of estrogen, especially regarding fat loss and body weight regulation (
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5835337/), brain health, heart health, bone health, and libido.
I can't find it now, but I believe there was a study done on men taking mesterolone as TRT, where they had a higher risk for osteoporosis then men taking testosterone. The only study I can find right now is this one, supporting the use of testosterone enanthate to increase bone mineral density rather than mesterolone, at least in men with secondary hypogonadism:
https://www.ncbi.nlm.nih.gov/pubmed/12792150
I respect your opinion tremendously, and I consider you one of the most intellligent people on the boards regarding TRT. I believe I have seen you post before that libido, in particular, is dependent on many elements, but primarily is finding the right balance for the individual of testosterone, estrogen, and DHT, correct?
Personally, I am having a very hard time getting OFF mesterolone. I started taking Bayer Proviron in November of 2017, to try to increase my sperm count (along with test, HCG, and HMG) to get my wife pregnant. That was successful, but now every time I try to decrease or cut out the Proviron, I feel miserable and have no libido. I have successfully replaced it with Masteron, which works well but gives me cystic acne. So now I'm back on the Proviron again, trying to find the right balance with my test dosage, and I don't seem to be able to come off the Proviron without feeling miserable.