2,5-Dimethoxy-4-methylamphetamine

2,5-Dimethoxy-4-methylamphetamine (DOM or STP, allegedly standing for "Serenity, Tranquility and Peace", but based on the motor oil company STP as named by Owsley Stanley) is a psychedelic (hallucinogenic drug) and a substituted amphetamine. It was first synthesized by Alexander Shulgin, and later reported in his book PiHKAL (Phenethylamines i Have Known And Loved). DOM is classified as a Schedule I substance in the United States, and is similarly controlled in other parts of the world. Internationally, it is a Schedule I drug under the Convention on Psychotropic Substances. It is generally taken orally.

History
In mid-1967, tablets containing 20 mg (later 10 mg) of DOM were widely distributed in the Haight-Ashbury District of San Francisco under the name of STP. This short-lived appearance of DOM on the black market proved disastrous for several reasons. First, the tablets contained an excessively high dose of the chemical. This, combined with DOM’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, DOM.

Effects
Effects of this drug include substantial perceptual changes such as blurred vision, multiple images, vibration of objects, visual hallucinations, distorted shapes, enhancement of details, slowed passage of time, increased sexual drive and pleasure, and increased contrasts. It may also cause pupillary dilation and a rise in systolic blood pressure.

Pharmacology
DOM is a selective 5-HT2A, 5-HT2B, and 5-HT2C receptor partial agonist. Its psychedelic effects are mediated by its agonistic properties at the 5-HT2A receptor. Due to its selectivity, DOM is often used in scientific research when studying the 5-HT2 receptor subfamily. DOM is a chiral molecule, and R-(-)-DOM is the more active enantiomer, functioning as a potent agonist of the serotonin 5-HT family of receptors; mainly of the 5-HT2 subtype.

The 2,6-dimethoxy positional isomer of DOM, known as Ψ-DOM, is also mentioned in PiHKAL as being active, as is the alpha-ethyl homologue Ariadne. Analogues where the methoxy groups at the 2,5- positions of the aromatic ring have been altered have also been synthesised and tested as part of an effort to identify the binding mode of DOM at the 5-HT2A receptor. Both the 2- and 5- O-desmethyl derivatives 2-DM-DOM and 5-DM-DOM, and the 2- and 5- ethyl analogues 2-Et-DOM and 5-Et-DOM have been tested, but in all cases were significantly less potent than the corresponding methoxy compound, showing the importance of the oxygen lone pairs in 5-HT2A binding.
 * Analogues and derivatives



Toxicity
Very little is known about the toxicity of DOM. According to Shulgin, the effects of DOM typically last 14 to 20 hours, though other clinical trials indicate a duration of 7 to 8 hours.