<unk>  (or STP, allegedly standing for Serenity, Tranquillity and Peace, but based on the name of STP (motor oil company) and thus named by Owsley Stanley) is a psychedelic hallucinogenic drug and a substituted amphetamine of the phenethylamine class of compounds, sometimes used as an entheogen.<unk>  was first synthesized by Alexander Shulgin. The full name of the chemical is 4-methyl-2,5-dimethoxyamphetamine.<unk>  has a stereocenter and R-(-)-DOM is the more active stereoisomer. In his book PIHKAL (Phenethylamines I Have Known and Loved), Shulgin lists the dosage range as 3 to 10 mg.<unk>  is generally taken orally. <unk>  is classified as a Schedule I substance in the United States, and is similarly controlled in other parts of the world. Internationally,<unk>  is a Schedule I drug under the Convention on Psychotropic Substances.
Not much information is known about the toxicity of<unk> .  According to Shulgin, the effects of<unk>  typically last 14 to<unk> 0 hours.  Clinical studies have indicated that repeated exposures to<unk>  can result in the rapid development of tolerance in as little as three days.
In mid-1967, tablets containing<unk> 0mg (later 10mg) of<unk>  were widely distributed in the Haight-Ashbury District of San Francisco under the name of STP.  This short-lived appearance of<unk>  on the black market proved disastrous for several reasons.  First, the tablets contained an excessively high dose of the chemical.  This, combined with<unk> ’s slow onset of action (which encouraged some users, familiar with drugs that have quicker onsets, such as LSD, to re-dose) and its remarkably long duration, caused many users to panic and sent some to the emergency room.  Second, treatment of such overdoses was complicated by the fact that no one at the time knew that the tablets called STP were, in fact,<unk> .
Another structural isomer of<unk>  is also known to be active. This compound has the methoxy groups at the<unk> ,6 positions instead, and is known as Ψ-DOM.
2,5-Dimethoxy-4-methylamphetamine
4-Chloro-2,5-dimethoxyamphetamine
3,4-Methylenedioxyamphetamine
Nicotinyl alcohol
Methamphetamine
Amphetamine
Benzidine
Benzocaine 