What the Ehrlich reagent shows, and what it does not
This version has been translated from Polish and links to the relevant test kits have been added. In a life-threatening situation call 112. This article is informational and serves harm reduction. It does not encourage the use of psychoactive substances and does not replace medical advice.
The Ehrlich reagent detects an indole. Not LSD, not DMT, not psilocin specifically, but the indole ring those compounds share, which it reports by turning purple. Everything that confuses people about ehrlich follows from that one fact: a purple result is a statement about a chemical family, and melatonin from a pharmacy gives the same purple as a tab of acid. That is exactly what hofmann is for, and it is why the two are sold together: run the pair and a deep blue separates a lysergamide from every other indole in about a minute.
LSD and adulterants kit, 26.53 EUR · Ehrlich reagent, 7.30 EUR · Hofmann reagent, 7,30 EUR
Why a blank result matters more than a purple one
On blotter, ehrlich is used backwards. Blotter paper holds about 100 to 200 µg and almost nothing fits on it at a psychoactive dose except lysergamides and the NBOMe series, the DOx compounds and NBOH. The first are indoles, the second are not. So a purple result narrows the field usefully, and a blank result on something sold as acid is the warning, because it is consistent with the compounds that have killed people at those doses.
NBOMe and DOx on blotter · Ehrlich reagent, 7.30 EUR · Ehrlich instructions
Three blanks that are not danger
A prodrug blotter such as 1P-LSD, 1cP-LSD or 1V-LSD reacts slowly or not at all until the sample is activated with a drop of alkaline reagent. 1S-LSD does not react at any point, because both ehrlich and hofmann work through p-DMAB. And a very small sample, an eighth of a tab, can give a reaction so faint it reads as nothing. None of those means the paper is dangerous, and all of them look identical to a blank.
The LSD prodrugs compared · The activation method · LSD and adulterants kit, 26,53 EUR
One purple that was a lie
We queried a 1P-LSD sample at DrugsData whose ehrlich photo looked wrong, since 1P-LSD is not supposed to turn ehrlich purple. It had been deliberately spiked with tryptamine, which does, so that the blotter would read as LSD-25. That is the clearest demonstration we have that a single reagent is not an identification, and it is why we pair ehrlich with hofmann as a matter of course.
The full account · LSD and adulterants kit · Hofmann reagent
Questions?
Does ehrlich prove I have LSD?
No. It indicates an indole is present. Hofmann separates lysergamides from other indoles by turning deep blue rather than yellow-green.
Will melatonin turn ehrlich purple?
Yes. So will tryptamine, which is what made the adulteration case above work.
Does ehrlich detect NBOMe?
No, and that is how it is used. NBOMe is not an indole and produces no reaction.
My tab gave nothing at all.
Either not a lysergamide, or a prodrug needing activation, or 1S-LSD, or too small a sample. Do not assume the reassuring option.