silocin (also known as 4-HO-DMT, 4-hydroxy DMT, psilocine, psilocyn, or psilotsin) is a substituted tryptamine alkaloid and a serotonergic psychedelic substance. It is present in most psychedelic mushrooms together with its phosphorylated counterpart psilocybin. Psilocin is a Schedule I drug under the Convention on Psychotropic Substances. The mind-altering effects of psilocin are highly variable, subjective and resemble those of LSD and DMT. Its physiological effects are similar to a sympathetic arousal state. Specific effects observed after ingestion can include but are not limited to tachycardia, dilated pupils, restlessness or arousal, euphoria, open and closed eye visuals (common at medium to high doses), synesthesia (e.g. hearing colours and seeing sounds), increased body temperature, headache, sweating and chills, and nausea. Psilocin acts as a 5-HT2A, 5-HT2C and 5-HT1A agonist or partial agonist. Receptors are claimed to significantly regulate visuals, decision making, mood, decreased blood pressure and heart rate. There is virtually no direct lethality associated with psilocin. There is virtually no withdrawal syndrome when chronic use of this drug is ceased. There is cross tolerance among psilocin, mescaline, LSD, and other 5-HT2A, 5-HT2C, and 5-HT1A agonists due to down-regulation of these receptors.