Is there a natural version of Low Dose Naltrexone (LDN)?

Is there a natural version of Low Dose Naltrexone (LDN)?


Field poppies contain something like naltrexone. Natural versions of LDN are outside of my area of expertise. 

Poppies are actually the source of opium. So this is where our all narcotics sort of derived from. So that's where morphine is derived from. So that overlapping analogue of structure. 

It wouldn't surprise me if there was a natural version of this. This is very, very cool idea,but it's outside of my area of expertise and I would love to look into it,but I can't answer that intelligently past that discussion.