Scalp Testosterone?

Dr Rassman

Can you please tell me the role of scalp testosterone (not serum) in hair loss/growth?
Thank you

The scalp does not make testosterone, but it does metabolize it with the enzyme 5alpha-reductase, the same enzyme that Propecia (finasteride) blocks. During the metabolism of testosterone in the scalp, 5alpha-androstane-3beta-17beta-diol appears to be formed and the formation of androstanediol (a steroid byproduct created by the hair apparatus in the metabolic process) has some effect on the functioning of the sebaceous glands, as well as (possibly) accelerating the hair loss. It probably impacts the sweating and the sebum production. We really do not know this for sure so I would consider what I said here as an intellectual logical exercise (taken from what I read which incidates that much of this information is based upon experimental work from in-vitro research studies).

On a practical level, I think that you may be thinking about the length of time it takes to block DHT production. The answer here may be in the duration of action of the particular DHT blocker you are using. Propecia has a 5 hour half life, Avodart has a half life in months and other claimed DHT blockers do not have a clearly defined life of action. It is better off sticking with known drugs that are fully researched by standards established by such bodies as the FDA.