4-D (3,5-methoxy-4-trideuteromethoxyphenethylamine) is a lesser-known recreational psychedelic drug.

In his book PiHKAL, the dosage is listed as approximately 200–400 mg for the sulfate salt, and 178–356 mg for the hydrochloride salt.

It causes closed-eye visuals, mild open-eye visuals, color distortion, and mydriasis.

[1] Very little data exists about the pharmacological properties, metabolism, and toxicity of 4-D.

This psychoactive drug-related article is a stub.