2C-x is the general name for the family of synthetic phenethylamines originally studied by Alexander Shulgin. Shulgin first synthesized most of the 2C-x chemicals in the 1970s and later published his findings in his book PiHKAL. The 2C-x chemicals vary in effect from being totally inactive to fully psychedelic.
List of 2C-x compounds
Health effects, potential addiction and tolerance
The 2C-x chemicals, as with many other serotonergic psychedelics, should not be taken in combination with SSRIs (selective serotonin reuptake Inhibitor) or tricyclic antidepressants in general to avoid Serotonin Syndrome, a potentially life-threatening condition in which an abundance of serotonin is built up the body, causing many physical and cognitive health problems.
Although many psychoactive substances are reasonably safe to use on their own, they can quickly become dangerous or even life-threatening when taken with other substances. The following lists some known dangerous combinations, but cannot be guaranteed to include all of them. Independent research should always be conducted to ensure that a combination of two or more substances is safe to consume. Some interactions listed have been sourced from TripSit.
- 5-meo-xxt - The 5-MeO psychedelics can interact unpredictably to potentiate other psychedelics
- amphetamines - The anxiogenic and focusing effects of stimulants increase the chance of unpleasant thought loops. The combination is generally uneccessary because of the stimulating effects of psychedelics. Combination of the stimulating effects may be uncomfortable.
- cocaine - The anxiogenic and focusing effects of stimulants increase the chance of unpleasant thought loops. The combination is generally unnecessary because of the stimulating effects of psychedelics. Combination of the stimulating effects may be uncomfortable.
- maois - MAO-B inhibitors can increase the potency and duration of phenethylamines unpredictably"]
- tramadol - Tramadol is well known to lower seizure threshold and psychedelics raise the risk of seizures.
- Austria: The 2C-x family is illegal to possess, produce and sell under the SMG (Suchtmittelgesetz Österreich) or the NPSG (Neue-Psychoaktive-Substanzen-Gesetz Österreich).
- USA: In the US, most of the 2C-x chemicals are Schedule I under the American Food and Drug Administration Safety and Innovation Act of 2012 and the Federal Analogue Act.
- Australia: Australia has a blanket ban over all substituted phenethylamines including the entire 2C-X family.
- Switzerland: Most 2C-x drugs are illegal to possess, produce and sell.
- Canada: All 2C-x phenethylamines are schedule III in Canada. 
- United Kingdom: Most of the 2C-x chemical class are Class A drugs in the United Kingdom as a result of the phenethylamine catch-all clause.
- Germany: Most 2C-x compounds are controlled under BtMG Anlage I, making them illegal to manufacture, import, possess, sell, or transfer them without a license. Other 2C-x compounds are controlled by the NpSG, as they are derivatives of 2-Phenethylamine. Production, and sale is illegal. Possession and import, although illegal, is not penalized if intended for self-consumption.
- Dean, B. V., Stellpflug, S. J., Burnett, A. M., & Engebretsen, K. M. (2013). 2C or not 2C: Phenethylamine Designer Drug Review. Journal of Medical Toxicology, 9(2), 172-178. https://doi.org/10.1007/s13181-013-0295-x
- New Psychoactive Substances (National Drug and Alcohol Research Centre 2014) | https://comorbidity.edu.au/sites/default/files/cre/page/New%20Psychoactive%20Substances.pdf
- United Kingdom. (1977). Misuse of Drugs Act 1971 (S.I. 1977/1243). London: The Stationery Office Limited. Retrieved July 5, 2017, from http://www.legislation.gov.uk/uksi/1977/1243/made