4-D (psychedelic)

4-D, also known as 4-trideuteromethoxy-3,5-methoxyphenethylamine or as 4-trideuteromescaline, is a psychedelic drug of the scaline family related to mescaline. It is the isotopologue of mescaline in which the three hydrogen atoms at the 4 position have been replaced with the deuterium isotopes.

In his book PiHKAL (Phenethylamines I Have Known and Loved) and other publications, Alexander Shulgin lists 4-D's dose as 200 to 400 mg orally in the case of the sulfate salt or 178 to 356 mg orally in the case of the hydrochloride salt and its duration as 12 hours. The onset ranged from 20 minutes to about 1 hour. The drug produces hallucinogenic effects similarly to mescaline, with these effects of 4-D having been thoroughly described. It is thought to be very similar or indistinguishable in terms of properties, effects, and metabolism compared to mescaline.

The chemical synthesis of 4-D has been described. Other deuterated isotopologues of mescaline are also known, such as β-D (β,β-dideuteromescaline) and α-D (alpha-D; α,α-dideuteromescaline), among others. α-D may be resistant to the oxidative deamination that is known to occur with mescaline, which may result in it being more potent than mescaline. However, α-D is not known to have been studied.

4-D was described by Shulgin in his book PiHKAL in 1991. It does not seem to be a controlled substance in Canada as of 2025.

• Scaline

• α-D (α,α-dideuteromescaline)

• β-D (β,β-dideuteromescaline)

• d2-MDMA

• 4-D - Isomer Design

• 4-D - PiHKAL - Erowid

• 4-D - PiHKAL - Isomer Design