If you are worried about your hairline, or have incidences of prostate issues in your family, then 1mg/day of Finasteride(Proscar) may be the answer you’ve been looking for. It’s not recommended to exceed pharmaceutical dosage, or 5 mg/day. More might not be safe and might at some point cause DHT levels to become abnormally low.
Another alternative is Dutasteride(Avodart).
In comparison of Dutasteride and Finasteride, one study 5 mg of dutasteride daily resulted in a 98.4% inhibition of DHT levels where .5 mg lowered levels by 94.7%. Where as 5 mg of Finasteride resulted in only 70.8% inhibition of DHT. The negative side effect is a lowering of strength and muscle gain, users who take Dutasteride can suffer from a lowering of muscle gain and lack of libido. It is reported most bodybuilders take .5 mg every one or two days and take it as long as they are on steroid cycle.