The only evidence I can find at all that says Res is a DhT inhibitor is here. Res is included in one of the bottom paragraphs.

5-alpha-reductase inhibitor - Wikipedia, the free encyclopedia

But it's pretty obvious it just got added in on this Wiki page about 5AR inhibitors with out much thought.

I have been using the Res from wicked every two days with my Herb/mineral cycling. I'm pretty sure I'm the most 5Ar inhibitor paranoid person on here. Some times people walk by me in public and I think that I hear them whispering 5 Alpha Reductase inhibitor as they walk by.

LOL and with that said so far I'm feeling nothing that would suggest I'm taking anything that inhibits DHT. Based on my past experiences with Saw P I think I would have felt something by now.