An interesting article published in The Conversation and written by Francisco Suárez, professor of physiology at FCS, describes how nature is the largest source of drugs on the planet. 

The dissemination work delves into the possibility of finding toxic substances, poisons and drugs in nature, which have the potential for pharmacological use. substances like Dimethyltryptamine (DMT), synthesized by our neurons but also by different plant species or even by some toads, can have a detrimental effect on health but also, with the correct dose and treatment, they give us their therapeutic effect. 

As the author expresses, "the world of drugs may seem eccentric, but it contains thousands of keys that will help us to know ourselves better, and, surely, many therapeutic weapons."