This is primarily the result of Testosterone converting into a much stronger androgen, Dihydrotestosterone (DHT). While Testosterone itself is moderately androgenic, DHT is several times stronger than male androgen. Testosterone undergoes conversion (or more formally, reduction) into DHT by way of the enzyme known as 5-alpha reductase (5AR). This enzyme is present in high concentrations in tissues such as the scalp, prostate, and underneath the skin. When Testosterone circulates throughout the bloodstream and passes through these tissues, the 5AR enzyme will bind to a certain percentage of the Testosterone that is present, and reduce it into Dihydrotestosterone.
Finasteride is an inhibitor of 5-alpha reductase, and this is a method of activity that Finasteride works through in the body. It is important to note that 5AR inhibitors like Finasteride are successful only in reducing or preventing the conversion of Testosterone into DHT, and it is effectively useless if the athlete or bodybuilder is using other anabolic steroids that completely avoid the 5AR enzyme (or anabolic steroids that are already derivatives of DHT). Bodybuilders and athletes will typically use Finasteride in cycles with moderate to high dosages of Testosterone.
For the treatment of androgenic alopecia (male pattern baldness) in males, the prescribed medication dosage is usually 1mg daily for 6-12 months. For the treatment of BPH (prostate enlargement), a higher medical dose is prescribed, which is usually 5mg daily for an extended duration.
For bodybuilders and athletes looking to reduce the androgenic effects of Testosterone conversion into DHT, the recommended Finasteride dosage is 1mg per day for the duration of use that Testosterone is used. Many athletes and bodybuilders also take the approach with Finasteride that it should be used only when necessary, and not automatically taken all the time whenever a cycle is run.
Finasteride 5mg x 100 Tablets.