Not a physician, but a PhD in neuroscience with a specialty in drug addiction.

Ibogaine and Ayahuasca both undoubtedly have therapeutic potential. However, there are certainly dangers related to both as well. Ibogaine disturbs cardiac rhythms (http://www.ncbi.nlm.nih.gov/pubmed/25642835), and sudden unexplained death has been reported following small ibogaine doses (e.g. http://www.ncbi.nlm.nih.gov/pubmed/24112325). More research definitely needs to be done here. But, research is not being done (in the US), because we have stamped it with the Schedule 1 tag that "dictates" that there is no medical use and a huge abuse potential. The inability of the DEA to examine research, admit faults, and reschedule drugs when a medical potential is found for them is absolutely astounding. I would imagine that if proper resources were given to clinical research on ibogaine treatment, the safest and most effective method could be discovered in less than a decade. I have a Schedule 1 license from the DEA to study drugs in preclinical models, and even with my license I wouldn't be willing to do experiments on ibogaine and cardiac or hepatotoxicity. The terms of the license are simply too restrictive.

The other interesting one is MDMA. This is one that the DEA has waivered on slightly, and clinical research is being done to further examine the benefits of MDMA on PTSD. I am not hopeful for the future of these experiments. The current interest is an acute effect of the mass recall of soldiers from the middle east. Similar research was conducted following the Vietnam war, the last time we had a huge number of veterans stateside that were suffering from PTSD. Even in the 70s when that research was being conducted it was shown to be massively beneficial, even in single-trial acute doses. But, I am not hopeful because before any actual litigation occurs, years will pass and the PTSD issue will have slightly dissolved, and the need for MDMA as a treatment for PTSD will have fallen out of the public eye.