| Ask Dr. Shulgin | | Information about psychedelics, entheogens, empathogens (MDMA, Ecstasy), from a pharmacologist and chemist. |
| Cluster Busters | | Information regarding the use of hallucinogenic substances for the treatment of cluster headaches and other vascular headaches. |
| Erowid Psychoactive Vaults | | Information on entheogens, psychedelics, and hallucinogens including traditional, spiritual, and responsible use, chemistry, effects, experiences, images, research, legislation, media coverage, bibliographies and links. |
| HPPDonline.com | | Information and message boards for people with Hallucinogen Persisting Perception Disorder (flashbacks). |
| Serendipity: Psychedelics | | Articles on psychedelic mushrooms and DMT (with field notes on DMT experiences); LSD and Ketamine trip reports; preservation of dried psilocybin mushrooms; links to other documents concerning psychedelics. |
| Status of Ololiuhqui in Mexico |
| The Psychedelic Library | | Menu of articles, research papers, books, and essays on LSD, peyote, psilocybin, and the use of psychedelic drugs in research, therapy, religion and personal growth. |
| Tryptamind | | Resource on psychoactive, psychedelic and hallucinogenic plants and the pharmacological effects of their active chemical constituents. | |
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