The active metabolite of tramadol goes into Schedule I on publication, and the statute says an order of this kind is not subject to judicial review
One hundred and forty-seven encounters, across 30 states, since the first one in 2011.
That is the whole of the seizure record the Drug Enforcement Administration cites for O-desmethyltramadol, the metabolite the liver makes from tramadol, in a temporary scheduling order filed on Tuesday morning that places the substance in Schedule I. The count comes from the National Forensic Laboratory Information System on a query dated 11 May 2026, and the agency says it is probably low, because not every forensic laboratory can test for the compound.
In 118 of those 147 cases, 80.2 percent, it was the only drug present.
Why the metabolite and not the parent drug
Tramadol is approved in the United States as a pill and nothing else, which means it has to be swallowed and passed through the liver before it does very much. The enzyme CYP2D6 strips a methyl group off it, and what comes out the other side is the compound that actually binds the mu-opioid receptor. The document gives the two binding affinities side by side: a Ki of roughly 3.4 nM for the metabolite against roughly 2400 nM for tramadol itself.
Take the metabolite directly and the liver step is skipped entirely.
The potency comparison is drawn from a randomised, double-blind trial in 103 healthy participants, which found 20 mg of the metabolite equal in analgesic effect to 50 mg of tramadol at steady state. The same section notes what pharmacogenetics has known for years, that people classed as CYP2D6 ultrarapid metabolisers carry about 40 percent more of the metabolite in serum than poor metabolisers, which is why prescribing guidelines tell clinicians to avoid tramadol at both ends of that range for opposite reasons.
The record on harm
The agency's public health case leans on a Swedish series. Ten forensic medical investigations between October 2009 and October 2010 found the metabolite and mitragynine, the kratom alkaloid, together in the blood of the deceased. In nine, the death was explained by intoxication with the metabolite. The ages ran from 22 to 35, blood concentrations from 0.4 to 4.3 micrograms per gram, and every one of them died before reaching a hospital. All the deaths were recorded as accidental.
Elsewhere in the seizure record the compound turns up mixed with heroin, fentanyl, acetyl fentanyl, para-fluorofentanyl, methamphetamine, cocaine, bromazolam and kratom, among others.
What the order is, and what it is not
This is not permanent scheduling. Section 811(h) lets the agency place a substance in Schedule I for two years without going through the eight-factor evaluation, on a finding that it is necessary to avoid an imminent hazard to public safety, and only Schedule I is available for that route. The order expires on 12 August 2028 unless extended by a further year while the permanent process runs.
The two processes differ in one respect the document states without comment. Permanent scheduling is formal rulemaking on the record after opportunity for a hearing, and the decision that ends it can be taken to a court of appeals under 21 U.S.C. 877. A temporary scheduling order cannot. Congress said so at 21 U.S.C. 811(h)(6).
The clock behind this one is long. The DEA notified Health and Human Services of its intent by letter dated 27 May 2025, and HHS replied on 11 June 2025 that the Food and Drug Administration had found no approved and no investigational applications for the substance, and that it had no objection. The notice of intent was published on 24 June 2026, thirteen months later.
