Finasteride is an inhibitor of type II and type III 5α-reductase enzyme.

By inhibiting 5-reductase, finasteride prevents the conversion of testosterone to dihydrotestosterone (DHT). Type II and III isoenzymes lead to a decrease in serum DHT levels by about 65-70%, and in the prostate, DHT levels decrease up to 85-90%, where the Type II isoenzyme presented mostly. Unlike triple inhibitors of all three 5a-reductase isoenzymes, such as dutasteride, which can reduce whole-body DHT levels by more than 99%, finasteride does not completely inhibit DHT production because it lacks a significant inhibitory effect on the 5a-reductase type I isoenzyme.

By blocking the production of DHT, finasteride reduces androgen activity in the scalp. In the prostate, inhibition of 5a-reductase reduces prostate volume, and decreases prostatic hyperplasia, which improves and reduces the risk of prostate cancer.

Inhibition of 5-reductase also reduces the weight of the epididymis and reduces the motility and normal morphology of spermatozoa in the epididymis.

Officially it is currently approved for the treatment of benign prostatic hyperplasia (enlarged prostate) and hair loss. Consider the scope of the drug in detail.

Prostate enlargement

Doctors use Finasteride to treat prostate hypertrophy. Finasteride may improve symptoms associated with such as decreased and painful urine flow.

It provides better symptomatic treatment than alpha-1 blockers such as tamsulosin, but symptom relief comes slower (treatment with Finasteride may take six months or more to determine the therapeutic outcome).

 In long-term studies, Finasteride , but not alpha-1 inhibitors, reduced the risk of acute urinary retention (-57% at 4 years) and the need for surgery (-54% at 4 years). When you stop taking the drug, changes in the prostate are restored within 6-8 months.

Hair loss

Finasteride is used to treat hair loss (androgenetic alopecia) in men only. The treatment can not fully restore the hair, but it slows down further hair loss and provides about 30% improvement in hair loss after six months of treatment, but it is effective only as long as the drug is taken.

Finasteride has also been tested for hair loss in women, but the results were no better than placebo.

Donald Trump's personal doctor says Trump is taking Finasteride to promote hair growth.

Excessive hair growth

Finasteride has been found effective in the treatment of hirsutism (excessive growth of hair on the face or body).

 In a study of 89 women with hyperandrogenemia due to persistent puberty syndrome, finasteride produced a 93% reduction in facial hirsutism and a 73% reduction in body hirsutism after 2 years of treatment.

Other studies using Finasteride for hirsutism, including in men, have shown the drug to be effective.

Doping status

From 2005 to 2009, the World Anti-Doping Agency banned finasteride because it was found that the drug could be used to mask steroid abuse. It was removed from the list at 2009, after improvements in testing methods made the ban became unnecessary.

Application in sports

Finasteride is used to block the enzyme 5α-reductase, and avoid the negative effects of its interaction with steroid hormones like testosterone.

For people, who use steroids, it will be important to be able to avoid the excess of androgenic side effects with high doses of testosterone, or another drug, especially in the case if a sufficiently aesthetic appearance is needed, for example in the model business, actors etc.

Women who are afraid of virilization, but take testosterone as doping in sports, also often resort to Finasteride to reduce androgenic side effects, however read the warning below.

ATTENTION

Finasteride is not intended for use in women during or before pregnancy due to the risk of birth defects in the fetus. It is classified by the FDA in pregnancy category X.

However, not only testosterone undergoes a transformation when interacting with 5α-reductase.

In our previous article, we wrote about Nandrolone and its side effects in the brain caused by one of its metabolites -5α-Dihydronandrolone.

It is a major metabolite of Nandrolone and it formed by the actions of the enzyme 5α-reductase analogously to the formation of dihydrotestosterone (DHT) from testosterone

Unlike the case of testosterone and DHT, 5α-DHN is a much weaker agonist of the androgen receptor (AR) than is Nandrolone  itself, but it blocks the androgenic receptor for a longer time, so the amount of negative side effects on 5α-Dihydronandrolone is high.

The combination of Nandrolone with a 5α-reductase inhibitor like Finasteride will block the conversion of Nandrolone into 5α-DHN and, unlike with testosterone and various other AAS, thereby considerably increase the propensity of Nandrolone for producing androgenic side effects.

Thus, such an unfamous drug as Finasteride can be of good service to a knowledgeable athlete!