(S)-5-Chloro-α-(cyclopropylethynyl)-2-[[(4-methoxyphenyl)methyl]amino]-α-(trifluoromethyl)benzenemethanol-D4 is a labelled analogue of (S)-5-Chloro-α-(cyclopropylethynyl)-2-[[(4-methoxyphenyl)methyl]amino]-α-(trifluoromethyl)benzenemethanol (C366130).