If you are using cycles that are test only or test + EQ fina is the best option. It is a 5-AR and at a dosage of 1.25 mg a day will reduce the Type II isoenzyme of DHT by up to 90%.
That is significant enough to ensure a low enough level of DHT to minmize any hair loss.
Do not use fina with Deca - Deca needs to interact with the 5-AR enzyme to reduce to DHN - a much less androgenic AAS.
Using Tren, Dbol, or Abombs and there is nothing that will stop those compounds from ravaging your hair line.
DHT-rduced AAS like Anavar (var), Winstrol, Masteron do not interact with the 5-AR enzyme so fina has not effect on them whatsoever. Most DHT-reduced AAS are already much less androgenic than test and have considerably less impact on the hair line.
Rogaine foam will also help significantly. It is cheap too! go to Sams club and get 4 cans for $50 - that will last 4 months.
Go to your local Dr. and tell him her your worried about your hair loss. Ask him/her to script you on 5 mg Proscar. Get it filled as a generic at CVS or Walgreen. With insurance it is $10 buck for 90 tablets. Cut each tablet into 4 pieces - then you have 360 1.25 mg pieces - enough for a whole year.
Side effects with fina occur in less than 2% of the people using the drug. The most common is Gyno as fina will actually raise your Test level b/c it inhibits the Test from being convert to DHT hence more test in your system. If you are using an Aromatase inhibitor (AI) on cycle, gyno should not be an issue anyhow. Other side effects include ED. It is reported in 1.8% of the users of the drug.
I've used the drug for 17 years consecutively now plus I've reviewed all 244 of the published medical studies that describe the effects on more than 16,000 test subject.