I took ayahuasca many times. Also smoked dmt and the Sonora desert toad (bufo alvarius). It was great. Never had any bad thing. But at some point I stopped. I heard someone say "the world of spirits is not an amusing park. You will die one day and be a spirit full time. There´s a lot of work to do while we are here (in the flesh)". He was damn right. I wouldn´t mind trying iboga once, though.