Presley Gerber Death: Ibogaine Activist Says Drug Can Save Lives, Isn't Miracle Cure

Presley Gerber may have hoped to fend off his addiction issues with ibogaine, but one expert says it's not as simple as taking a magic pill ... diving into the realities of the treatment.

Bryan Hubbard, the CEO of Americans for Ibogaine, joined "TMZ Live" Monday to discuss the psychoactive drug that Presley took a few months before his death.

Bryan described the substance for us in detail ... explaining how it's known to rewrite neural pathways -- and give people with addiction a fighting chance against their demons. He also notes a major risk with ibogaine.

He makes it clear the drug isn't a magic pill or a one-off cure ... it's supposed to give a chance to make better future decisions by giving them a window of "neurochemical restoration" to clear them of the need for drugs and to blunt withdrawal symptoms.

Bryan notes we don't know what happened specifically with Presley -- who died in a rehab facility on Sunday ... but says it's important to investigate it further to help people struggling just like him in the future.

As we reported ... Presley previously shared a video of a person administering the "Ibogaine Flood Rush" -- waving smoke all around his body as he stood in a grassy field. Both of his parents, Cindy Crawford and Rande Gerber, and his sister, Kaia Gerber, showed their support in the comments.

Cops are looking into Presley's death as an overdose. According to dispatch audio, he suffered cardiac arrest before he died.