If people don’t experience side effects when inhibiting their DHT levels through Saw Palmetto, Nettles or Pygmeum (Procerin, Provillus), then I think it’s safe to assume that these herbal treatment remedies are ineffective, and a scam. The Finasteride in Propecia is proven to lower DHT, but DHT plays a crucial role in both sex drive and the growth of muscle tissue, hence, the side effects. 
I doubt you’ll find many here interested in lowering DHT, since that’s what Finasteride did, and which caused us problems in the end.
If you are still wanting to lower DHT for hairloss purposes, please visit a hairloss forum.
No, no, I’m just saying you shouldn’t take these alternatives either. If you lower your DHT you should experience the same side effects.