It’s not a testosterone blocker at all. It blocks 5-alpha reductase, an enzyme that converts testosterone to DHT. It can actually increase serum testosterone by

It’s not a testosterone blocker at all. It blocks 5-alpha reductase, an enzyme that converts testosterone to DHT. It can actually increase serum testosterone by more than 10%. As for DHT, that hormone doesn’t appear to have much significance for adult males. It’s critically important in puberty, though!