What is Ketamine Precursor A?

It’s been noticeable that most (nine out of ten) ketamine samples analyzed by DrugsData since March 2019 have contained 1-[(2-Chlorophenyl)(methylimino)methyl]cyclopentanol (CAS #6740-87-0), or “Ketamine Precursor A”. Synonyms of this substance in the literature include “Ketamine Related Compound A” and “Ketamine Impurity A”.

Since 2019, only 37 ketamine samples have been analyzed by DrugsData that contain only ketamine (zero in 2022). An additional 297 sample contained Ketamine + Ketamine Precursor A, and 19% of these 297 samples also contained MSM.

Ketamine Precursor A has been notably present in black market ketamine, but should not be present in commercial, pharmaceutical ketamine inside the United States or Europe.

Ketamine Precursor A is not considered harmful, just a waste of mass and chemical. We do not know of any good research on its toxicity, but unfortunately, most drug research that shows “no effect” doesn’t get published. If it were super toxic, we’d probably know about it.

A subreddit has covered this topic: https://www.reddit.com/r/AskDrugNerds/comments/e6iz5r/any_info_on_ketamine_impurity_a_and_whether_or/

We don’t know anyone who has tried it on its own, but it’s unlikely to be active within 10x the dose of ketamine. Just a boring contaminant.

If you have any insights to contribute about Ketamine Precursor A, please let us know, info(at)drugsdata(dot)org.