I've taken Cyproterone acetate, Spiro, Finasteride and Dutasteride before.
Siterone(CA) is by far the most effective and is 4 times stronger than Spiro. So 50mg of it equals 200 of Spiro. It's also a mild progestin and had no undesirable side effects for me. The only drawback I've read of is possible long term liver damage, but that was at the doses given to chemically castrate sex offenders (usually around 200mg daily). The effect on the liver is dose dependent so 50mg daily shortterm is unlikely to cause much harm. Also, it is not available in the US so you'd have to order from an online pharmacy. I actually still have some lying around. lol...i had blood tests after a few months solid on it and my total T was 75 ng/dl. This is female range....the drug is very effective imo. I took it on my own authority off and on for about a year
Anyways, after I saw an endo and got on official HRT I switched to Spiro mainly for how cheap it is. Even at 200mg daily, I feel like it's weaker than my old 50mg siterone routine.(I can comment more on its strength after i have my blood tests on the 1st) At first I peed a lot more, but after about a week it was fine. I've been on it for almost 3 months with no issues. As long as your sodium intake is normal, potassium shouldn't be a problem provided you read labels and avoid overeating foods high in vit K or loaded with potassium. I stopped eating bananas and limited leafy greens and have been feeling great!
Fincar/Dutasteride are DHT inhibitors. I take them only because I live in fear of DHT. It's very hard to comment on the efficacy of either, but I can say neither has given me any bad side effect. I'm honestly not sure I have that much free T to even worry about DHT conversion, but I don't need my facial hair regrowing and making my monthly laser sessions pointless!
Of course, I'm not counting the loss of spontaneous erections or "shooting blanks" as side effects for any of the drugs listed above. It's par for the course, and I enjoy both changes lol...