How Finasteride works after you take it,
1. DHT drops
2. T increases by 20-40%
3. Dopamine increases and serotonin decreases in parts of brain
4. SHBG increases
5. E2 increases
6. FSH decreases (hence why people experience watery semen or lower sperm)
7. LH significantly decreases
8. Due to lower LH, difficulty to turn cholesterol into pregenolone
9. Increase in Cholesterol due to 5-ar action decreased in liver
10. Decrease in progesterone and its ability to convert to dihydroprogesterone
11. Increase in Cortizol / Decrease in Dehydroepiandrosterone sulfate (DHEA-s)
12. Disrupt in the production of all 5-alpha steroids (testosterone, 5a-androstan-17-diol etc)
This is a line of events. You won't find it in any online forum because people there are morons. Suffering or not, they are morons. Same goes for people spamming YouTube videos about random sh*t, some are Merc's employees, some are from other companies, some are depressed weirdos. Ignore them all.
This line of events shows why you feel what you feel and the testicular pain is also explained but I don't have the chart with me right now to post, however it isn't random or not to worry.
The cold, hard fact is that this drug can, at any time, permanently reverse the way the enzyme is produced and/or prevent its regeneration. Which is why you see people with permanent sides because when they experienced symptoms, they continued the drug, some in extremely high doses.
There is also research done for the dose and that 1mg is way higher than enough, which leaves more finasteride in the bloodstream and the theories about sides emerge.
Anyone who wants to start the drug needs to follow a specific recipe,
a. Have health insurance.
b. Prepare to have many blood tests done every month.
c. Monitor the hormones mentioned especially if you are a thyroid patient (Hypothyroidism, Hashimoto, T4 Levothyroxin therapy etc)
d. Have a secondary plan of action for hair loss (assuming you are the typical sebum/oily head with miniaturized folliclues), such as treatment with oils, sauna and lazer comb, cleaning the pores and strengthening your scalp. Basically, you keep your head as clean as possible at all times to prevent the damage done from within to kill the follicle.
e. Minoxidil, be prepared for mild to heavy sides depending on how you react to it. Don't sleep with it.
f. Have a healthy diet, sex life and exercise (running, swimming, not weights). Those are the actual "big three".
g. If you choose to take finasteride, take it before, during and after a hair transplant to at least prevent shock loss. After that, be prepared for a conservative method of preserving hair.
Taking the drug for years is clearly playing with fire. Apparently, and we don't need a research for that, some appear to be way more resistent than others. Some are hyper-sensitive. The drug also contains Lactose, to which some are also sensitive. If you look at the chemistry behind the drug and what it really does in detail, you're gonna get dizzy. Certainly not a drug to mess with if you're not sure. As far as the "2% anecdotal reports" that some surgeons mention, they do because they work with the drug (a ton of money behind the scenes). Not that they are wrong to want to have a stabilized scalp to work with. Drug can also cause the donor area to increase in density, due to the fact that some people suffer from random pattern alopecia (can't remember the term now) that "takes" hair from everywhere. If that is not determined by the doctor, hair that is transplanted will fall in the future (which is why you hear people complain that after 5-6 years many of their grafts fell permanently, even though they were from the "safe" zone).
In my humble opinion, trying out the drug means nothing. This, as well as Minoxidil, is a recipe that needs to be with you for 7 years (since it loses its efficacy around that time with most people). Either take it for years and be prepared to play heads or tails with your hormones OR have the transplant without it and play heads or tails with your existing hair / scalp. It's a double-edged sword and the realization of it alone will relief some of your stress. In the end, it's your call. I hope this was of some help. I myself am a Norwood 2 but blessed with pretty good bone/face structure and was contemplating on the drug for a mild hair transplant and will probably take it for a year if I am lucky enough to respond well to it.