Ayahuasca, a traditional psychoactive psychedelic brew, helps to reduce the fear response, finds a new study in rats, working equally well on both new and old fear memories, via its effect on serotonin receptors.
Source: psypost.org
https://www.psypost.org/ayahuasca-accelerates-fear-extinction-via-its-effect-on-serotonin-receptors/