Hey guys,
I was looking at an amino acid supplement from Cellucor, actually purchased it and used it twice because I felt it was alright, even with an artificial flavor. However, today I looked up one of the ingredients in it, and sure enough, it has 5AR inhibiting properties. I attached the link to the study below. The substance is Black pepper fruit extract or Piper nigrum fruit extract.
https://www.jstage.jst.go.jp/article/bpb/30/12/30_12_2402/_pdf/-char/en