Ok, I know this thread is old, but I prefer to add info rather than having seven threads on the same subject.
I have researched throughout the site and found the most "expert" opionons on finasteride use to prevent accelerated hairloss while on AAS.
Genetic makeup determines if hair follicles are sensitive to the DHT hormone (dihydrotestosterone), causing them to shrink. This "shrinkage" results in overall thinning hair with time. Finasteride acts by stopping the formation of Dihydrotestosterone.
Finasteride is an 5AR enzyme inhibitor, and if i am correct AAS covert to DHT through this manner.
Here are a few educated opionons I have found:
"Psychological issues could be argued but the issue of an effect upon body composition has already been answered pretty thoroughly, within the literature, though I still see the topic discussed widely on the Internet. Skeletal muscle possesses little to no 5 alpha-reductase activity (unlike tissues such as the prostate and scalp as you're concerned with) and thus the idea that a 5 alpha-reductase inhibitor is going to have a negative impact is unlikely. This is a good reminder to always consider the effects upon the tissue and not simply in serum.
In support of this, when administering finasteride and testosterone concurrently in men, they've found that there was no significant difference in terms of an effect upon body composition in those receiving testosterone versus testosterone and finasteride.
(J Clin Endocrinol Metab. 2005 Mar;90(3):1502-10) Along those same lines, the general consensus from the available data is that finasteride only has a minimal effect upon libido, strength, fertility, etc.
Just for the sake of discussion, the increase in testosterone seen with finasteride could be one of two things and I've seen authors hypothesize both. One is that since you're inhibiting 5 alpha-reductase, you're preventing the normal 5 alpha-reduction of endogenous testosterone and thus you're going to have a higher circulating amount. The other is that by inhibiting 5 alpha-reductase in the brain, you're allowing for a lesser degree of androgenic negative feedback, thus increasing endogenous testosterone production. In any event, in clinical studies, you don't always see an increase in testosterone, and I do remember in one, it only lasted a short time before returning to baseline.
If it were me, hopefully now that my concerns about body composition were not as great, I'd at least give it a try. Even in those who have found that it caused depression, it generally dissipates upon cessation of use. I would also however, have a thorough discussion, if you decide to use it, with your physician about the possibility for gynecomastia and monitoring for it and any other potential side effects. "
Gang of Five answeared this same question with...
"We love this question! The reason that we love it is that we have almost perfected an over-the-counter topical hair loss solution utilizing a three pronged approach that starts working in 12 weeks. While working on this formula, we have subsequently become well versed about hormone-induced hair loss. The reason for the hair loss that you have described is likely multifactorial but we will address the DHT aspect of your hair loss.
Without admitting to having actually experimented with finasteride ( Proscar ) myself, let us just say that it is a very interesting drug. Your hair is likely falling out, in part, secondary to the elevation of DHT that occurs when serum androgens are elevated. Your hypothesis about androstenedione and DHEA being the culprits is probably right on the money. Believe it or not, so is your solution.
Using finasteride to combat this type of DHT elevation is a very intelligent and simple method of hair loss minimization. You will not "counter" the androgens used to gain muscle nor will there be any negative "biochemical stuff" occurring as a result of finasteride administration. There are even studies that suggest that finasteride use in the 5mg per day range will increase your endogenous testosterone levels. We can't guarantee a complete remission of your hair loss but your idea will work better than any other out there (except for mine, of course). Keep on training and keep on thinking"
I am still in the planning/research phase of my first cycle and this is another check in the box.
So my question is this..... What has been some of your experiences with finasteride while on AAS?
Finasteride is generally given in 1mg daily doses. Would you recommend upping the dose while on AAS?
Thanks for any input.