Synthetic mescaline. Normally biosynthesized from peyote and some other cacti, mescaline was the first<unk>  compound to be extracted and isolated.<unk> s are a class of hallucinogenic drugs whose primary effect is to trigger non-ordinary states of consciousness (known as<unk>  experiences or "trips"). This causes specific psychological, visual, and auditory changes, and often a substantially altered state of consciousness. The "classical"<unk> s, the<unk> s with the largest scientific and cultural influence, are mescaline, LSD, psilocybin, and DMT. Most<unk> s fall into one of the three families of chemical compounds: tryptamines, phenethylamines, or lysergamides and many tend to act via serotonin 2A receptor agonism. When compounds bind to serotonin 5-HT2A receptors, they modulate the activity of key circuits in the brain involved with sensory perception and cognition, however, the exact nature of how<unk> s induce changes in perception and cognition via the 5-HT2A receptor is still unknown, although the fact that<unk> s reduce default mode network activity and increased connectivity between regions in the brain as a result is likely one of the most relevant pharmacological mechanisms underpinning the<unk>  experience, particularly ego death. The<unk>  experience is often compared to non-ordinary forms of consciousness such as those experienced in meditation, mystical experiences, and near-death experiences, which also appear to be partially underpinned by altered default mode network activity. The phenomenon of ego death is often described as a key feature of the<unk>  experience. Many<unk> s are illegal worldwide under the UN conventions, with occasional exceptions for religious use or research contexts. Despite these controls, recreational use of<unk> s is common. Legal barriers have made the scientific study of<unk> s more difficult. Research has been conducted, however, and studies show that<unk> s are physiologically safe and rarely lead to addiction. Studies conducted using psilocybin in a psychotherapeutic setting reveal that<unk> s may assist with treating depression, alcohol addiction, and nicotine addiction. Although further research is needed, existing results suggest that<unk> s could be effective treatments for certain forms of psychopathology.
Psychedelic drug
Psychoactive drug
Synthetic cannabinoids
Heroic medicine
Alcohol 
Substituted amphetamine
Antimanic drugs
Corrosive substance