||No, peyote does not contain strychnine. The only plant that contains strychnine is Strychnos nux-vomica. Other than mescaline, peyote contains dozens of alkaloids such as pellotine and hordenine. Most of them are in trace ammounts. Unfortunately, most of these alkaloids have never been studied in depth, so we really don't know what they do. It's possible that some of them could be poisonous at high enough doses, but they are not harmful in the amounts present in peyote.|
There are no known deaths related to the ingestion of Peyote, and despite rumors to the contrary, there is no strychnine in Peyote. As far as why it makes you feel sick and throw up, mescaline itself does this. Even pure mescaline makes most people vomit. Not only is peyote somewhat irritating to the stomach, but mescaline interacts with serotonin receptors. The vomit reflex is partially controlled by serotonin, so it is not surprising that mescaline and related drugs can make people feel ill.