Ehrlich Reagent Color Chart and How to Read It
Ehrlich reagent turns purple for indoles like LSD, DMT and psilocybin. The color chart, why no reaction on blotter is a red flag, and what it misses.
August 11, 2026 · Jordan Mercer
Contents
Ehrlich’s reagent answers one question: is there an indole in this sample? Indoles turn Ehrlich purple. LSD, DMT, and psilocybin are all indoles, so all three go purple, and Ehrlich cannot tell you which one you have. The reading that actually protects you is the opposite one. NBOMe compounds, the substitutes sold as acid that put people in emergency rooms, are not indoles and produce no purple at all.
The color chart
Ehrlich’s is p-dimethylaminobenzaldehyde in acid, and the only thing it colors is the indole ring. That makes for a short chart, which is a feature: there are very few ways to get a false positive.
| Substance | Ehrlich color |
|---|---|
| LSD | Purple (builds over minutes, may shade toward pink) |
| Other lysergamides (1P-LSD, ALD-52) | Purple, visually identical to LSD |
| DMT | Purple |
| Psilocybin mushroom material | Purple, but often muddy brown or barely visible |
| NBOMe (25I, 25B, 25C) | No reaction |
| DOx and other phenethylamines | No reaction |
| Blank blotter paper, inert filler | No reaction |
| Pyridoxine (vitamin B6) | Pink |
The reagent’s active ingredient condenses with the electron-rich indole ring to make a colored product. LSD, DMT, psilocin, and psilocybin all carry that ring, so they all read the same. The 25x-NBOMe series and the DOx compounds are phenethylamines with no indole ring, so there is nothing for the reagent to grab and the droplet stays the color it started.
That chemistry is also why Ehrlich is a class test and not an identity test. Every lysergamide analog on the market gives you the same purple as LSD-25, and no purple anywhere on the chart carries dose information.
Give it twenty minutes before you call it
This is the slowest reagent in a standard kit. DanceSafe’s current instructions say Ehrlich’s may take up to 20 minutes to react and that the result stays accurate for around an hour. Color often starts building within the first few minutes, but faint or absent at five minutes is not a final answer.
Reading it too early is the single most common Ehrlich mistake. Marquis gets read in 45 seconds and people carry that habit over. Gel tabs make it worse, since they are much denser than paper and react slower and fainter.
Running the test
- Cut a small corner of the tab, or put one drop of liquid on a white ceramic plate. You do not need to sacrifice the whole thing.
- Hold the bottle an inch or two above the sample and release one drop. Never touch the dropper tip to the sample, which contaminates the entire bottle.
- Check at one, two, five, and twenty minutes.
- Read under white light, against the printed chart in the kit.
- Compare against a blank, meaning a drop of reagent alone on the same plate, so you can see whether anything actually changed.
The other misread worth naming: blotter dye. Purple and blue tab art bleeds into the droplet and looks convincing. DanceSafe’s guidance is to look for a clear purple that tints the whole droplet gradually, not color leaching out along the paper fibers.
The non-reaction is why you own this reagent
Most reagent guides train you to look for the positive color. Ehrlich works the other way around. Purple tells you an indole is present and gives you no red flag, but it does not confirm LSD.
A non-reaction on blotter is specific and it is actionable. 25I-NBOMe and its relatives do not turn Ehrlich purple, and they cause seizures, severe hyperthermia, agitation, and deaths at doses that fit easily on a paper square. If your tab does not go purple, it is not acid. Do not take it. We wrote up that risk in more detail in should you test LSD.
What it cannot tell you
Dose. This matters more for LSD than for nearly anything else, because the active dose is measured in micrograms. A purple reaction looks identical on a 60 microgram tab and a 300 microgram tab. There is no at-home way to read blotter strength from a color, and what the seller claims is not evidence. Dose conservatively, and read how long an LSD trip lasts before you commit.
Purity and mixtures. Darker colors overshadow lighter ones, and a small quantity of a second drug may produce no visible change at all.
Mushrooms, in practice. You can grind dried material and drop reagent on it, but the reaction is often muddy brown or invisible because the plant matter is dense. A weak result on mushrooms is evidence of nothing. For what actually matters with mushroom safety, see the psilocybin guide.
What to run alongside it
Ehrlich on its own is not enough for a confident read on blotter.
- Hofmann reagent is the useful second test on lysergamides. It runs yellow and settles into a deep blue for lysergamides, while NBOMe reads yellow-orange instead. Two reagents pointing the same direction is a far stronger result than one.
- Marquis, if you have it, as an extra data point. Our Marquis reagent color guide covers how to read it.
- A fentanyl test strip for anything that is not blotter, especially powders. Reagents cannot see fentanyl at all. On a strip, one line is positive for fentanyl and two lines is negative, which is the reverse of what most people expect. Fentanyl strips belong in every kit.
For everything else about acid, including interactions and set and setting, see the LSD harm reduction guide. For choosing between reagent sets, our test kit comparison.
Purple for indoles, nothing for NBOMe, twenty minutes before you decide. Use Ehrlich as the rule-out test it is, back it with a second reagent, and have an Ehrlich LSD kit in a drawer before the night you need it.
Sources: DanceSafe reagent testing instructions, v17 | DanceSafe reagent reaction updates