[AbiDrew85]

Dustasteride inhibits two types of 5 alpha reductase (type I & II) , it'll tank total and free T. It looks like it has a surge (of T) in the first 30-45 days, most likely from negative feedback of lutenizing hormone.

There are currently three known types of 5AR. And no, dut by itself should have negligent effects on total and free T and massive effects on DHT. That's why they always pair it with either spiro in the states or cypro in most of Europe. Because spiro and cypro effect total and free T, but not 5AR, while dut effects 5AR but not total and free T, only DHT due to blocking two of the three known types of 5AR. Currently known 5AR inhibitors block only 1 or 2 of the three known types of 5AR. Dutasteride blocks types 1 & 2, finasteride only blocks type 1, some other one I can't remember the name of blocks 2 & 3, no synthetics block only 3. Plants are all over the place, some block only 1, 2, or 3, some block 1 & 2, some 2 & 3, none seem to block all 3 types. From what they've been able to find, however, type 3 is very low utilization anyways and doesn't take over if 1 & 2 are blocked, therefore blocking just 1 & 2 blocks generally 80-90+% DHT. Which is considered good enough. Blocking just type 1 generally gets ~50% reduction in DHT, while blocking just type 2 gets around ~40%, only if you could block all three could you achieve 100% no DHT. However, no matter how much DHT you block, free and total T will either remain unchanged or may even go up depending on if your body increases aromatization to compensate or not. Which is why 5AR blockers are always paired with T blockers for MtF HRT. When 5AR blockers are being used for things like BPH, prostate cancer, or hair loss, in men, it's usually paired with an aromatase blocker just in case the patients body decides to compensate through aromatization. Only in cis women are they not generally paired with anything at all, since generally it WILL improve aromatization, and that's just fine for them.