Overview: Guillermo Galdos reports on a psychedelic drug derived from toad venom, being sold in Mexico as a possible cure for mental illness and drug addiction. Galdos meets meets controversial doctor Gerry Sandoval, who demonstrates how he catches toads and extracts their venom as he claims the popularity of the natural drug has now made it more valuable than gold on the black market. Concerns are now mounting around the safety and sustainability of the unregulated drug, amid fears of negative long-term effects.