I dug up two research articles on zinc’s effect on 5AR. The first shows that when applied to the skin, it has a strong inhibitory effect on type I 5AR:
ncbi.nlm.nih.gov/sites/entre … d_RVDocSum
The second discussed in vitro effects on 5AR from the prostate gland. They found that zinc stimulates of 5AR at low concentrations, and strongly inhibits 5AR at high concentrations.
ncbi.nlm.nih.gov/sites/entre … d_RVDocSum
“The results show that when zinc is added at low concentrations the 5 alpha-reduction of testosterone is increased but at higher cation concentrations the metabolism is significantly inhibited.”
My only question would be, what is “low” and “high” concentration? Were these test concentrations adjusted to be comparable to physiological highs and lows, or just arbitrary, relative experimental high/low values? It’s hard to say, especially considering the experiments were performed in vitro.
Anyways, just food for thought.