Obviously I’m not the dr, but I have searched for the answer to this question before and come up with nothing – there doesn’t seem to be any supplements or drugs that can directly lower progesterone in any signficant way. In theory, inhibitory neurotransmitters such as gaba should lower progesterone since high progesterone is often a sign of stress.
Maybe a better (or the only) approach would be to treat the cascade of hormones that are affected by progesterone, rather than trying to lower progesterone itself.
ie, progesterone can raise prolactin levels when progesterone is already at optimum, and the elevated prolactin levels in turn upregulates E2 receptors, which increases E2 metabolism. In this case we could use dostinex to lower prolactin and/or DIM to lower estrogen signalling activity.
Progesterone also opposes DHT, and can prevent its conversion from testosterone. In this case we could use a topical DHT cream to raise levels.
I’m not sure though. There doesn’t seem to have been a lot of studies done on progesterone; in the web of hormones under scientific scrutiny it seems to have taken a backseat. Which is stupid, imo, because looking at what functions it performs in the body, it’s a lot more than just a “female hormone”.