4C (4C-x), also known as 4-substituted 2,5-dimethoxy-α-ethylphenethylamines, is a general name for the family of psychedelic and related phenylisobutylamines (α-ethylphenethylamines) having methoxy groups at the 2 and 5 positions of the phenyl ring and a 4-position substituent. These compounds are analogues of the 2Cs and DOx drugs, but the α-alkyl chain has been further lengthed (0 carbons for 2C, 1 carbon for DOx, and 2 carbons for 4C).
The most notable and well-known of the 4C drugs is Ariadne (4C-D). This drug produces only threshold psychedelic effects and has been described as non-hallucinogenic or as having "the alert of a psychedelic, with none of the rest of the package". These unique properties have made Ariadne of interest for potential therapeutic applications. In contrast to Ariadne, other 4C drugs, such as 4C-B, have been reported to be more significantly psychedelic. The pharmacology of the 4C drugs has been studied and they are known to act as serotonin 5-HT2A receptor agonists, but with lower efficacy than other related psychedelics like the 2Cs and DOx drugs.Sabnis RW. Novel Phenylalkylamines as 5‑HT2A Agonists for Treating Psychiatric Disorders. ACS Med Chem Lett. 2025 May 14;16(6):948-949.
4C drugs have been developed and/or studied by Alexander Shulgin, Daniel Trachsel, and Michael Cunningham and colleagues.
List of 4C drugs
Structure Name(s) Chemical name CAS # Ariadne (4C-D) 1-(2,5-Dimethoxy-4-methylphenyl)butan-2-amine 52842-59-8 4C-B 1-(2,5-Dimethoxy-4-bromophenyl)butan-2-amine 69294-23-1 4C-C 1-(2,5-Dimethoxy-4-chlorophenyl)butan-2-amine 791010-74-7 4C-EShulgin AT. Treatment of senile geriatric patients to restore performance. Patent US 4034113 1-(2,5-Dimethoxy-4-ethylphenyl)butan-2-amine 72667-79-9 4C-I 1-(2,5-Dimethoxy-4-iodophenyl)butan-2-amine 758631-75-3 4C-N 1-(2,5-Dimethoxy-4-nitrophenyl)butan-2-amine 775234-58-7 4C-P (4C-Pr) 1-(2,5-Dimethoxy-4-(n-propyl)phenyl)butan-2-amine 72667-81-3 4C-T-2 1-[2,5-Dimethoxy-4-(ethylthio)phenyl]butan-2-amine 850007-13-5 4C-TFM 1-[2,5-Dimethoxy-4-(trifluoromethyl)phenyl]butan-2-amine ?
Various other 4C drugs have also been studied and described.
See also Substituted methoxyphenethylamine, 2C, DOx PiHKAL (Phenethylamines I Have Known and Loved) The Shulgin Index, Volume One: Psychedelic Phenethylamines and Related Compounds 5C-D
References
External links Isomer Design POD 70: Unraveling Ariadne's thread with Dr. Mike Cunningham - Hamilton Morris - The Hamilton Morris Podcast