Reviewed August 2026 by the Corydalis Labs Technical Team. How we research and review.
The short version
Federal schedules
13-OH, tetrahydropalmatine, and Corydalis rhizome extract do not appear in the schedules at 21 C.F.R. Part 1308, nor on the DEA List I/II chemical lists, as of August 2026.
State kratom acts
These statutes define their scope around Mitragyna speciosa and its alkaloids. A corydalis-only product is not within that definition. State detail.
Read this part too
"Not a controlled substance" is a specific statement about one body of law. It does not settle how a finished product may be formulated, labelled, or marketed — those questions live under food and supplement law and consumer-protection law, and they are where enforcement in this category actually tends to land. We cover that separately.
Why the derivative is not captured
This is the part worth understanding, because it is the reason the position is durable rather than lucky.
The Controlled Substances Act extends control from a scheduled substance to its salts, isomers, and salts of isomers, where those forms are possible within the chemical designation. That principle is why derivatives of scheduled compounds are generally captured without needing to be listed individually.
But the principle only operates downward from a listed parent. Tetrahydropalmatine is not scheduled. Corydalis extract is not scheduled. There is therefore no listed parent from which control could extend to 13-OH — no mechanism, not merely an absence of enforcement.
Contrast 7-OH, which is a derivative of mitragynine. When regulators moved on that chemistry, the derivatives moved with it. The same logic caught pseudoindoxyl and MGM-15 in July 2026. What happened to each.
The Analogue Act question
The other route by which an unscheduled substance can be treated as controlled is the analogue provision at 21 U.S.C. §802(32). It requires that a substance be substantially similar in chemical structure to a Schedule I or II substance, and have or be represented to have a substantially similar stimulant, depressant, or hallucinogenic effect, and be intended for human consumption.
Courts have applied this provision principally to close structural variants of well-established Schedule I and II families — synthetic cannabinoids, cathinones, fentanyl analogues, phenethylamines, tryptamines. 13-OH is an isoquinoline alkaloid from a poppy-family plant with centuries of traditional use; it is not a structural variant of those families.
The part you control
Analogue determinations are fact-specific and turn substantially on how a product is marketed, labelled, and represented. A compound with a clean structural position can still be dragged toward trouble by a brand that markets it as a substitute for a controlled substance. This is not a theoretical concern — it is the single most avoidable risk in this category. Market it properly.
The primary sources
We would rather you read the law than our characterisation of it. The relevant materials are public:
- 21 U.S.C. §801 et seq. — the Controlled Substances Act itself.
- 21 C.F.R. Part 1308 — the schedules, including the salts-and-isomers language at §1308.11 and following.
- 21 U.S.C. §802(32) — the controlled substance analogue definition, including the factors relevant to "intended for human consumption."
- DEA's consolidated lists of scheduling actions, controlled substances, and regulated chemicals — commonly called the Orange Book — which is the practical place to check whether a substance is listed.
- Your state's kratom statute, if it has one, for its scope definition. Our state page.
Our reading of these is summarised on the regulatory summary page, written so you can hand it to counsel as a starting point for their own review.
What could change this
We are not going to tell you this position is permanent, because nobody honestly can.
- DEA can schedule substances through rulemaking, including on a temporary expedited basis. A substance that is unscheduled today can become scheduled.
- States act independently and often faster than the federal government.
- Agencies can take positions on ingredient status under food and supplement law that are separate from controlled-substance scheduling.
- Marketing conduct can change the analysis, as above.
What we can tell you is that the structural position here differs from the compounds that have recently been scheduled in this category, and that we maintain a tracker so you find out about changes from us rather than from a customer.
Common questions
Not as of August 2026. It does not appear on the federal schedules at 21 C.F.R. Part 1308 or on the DEA List I/II chemical lists. Verify current status yourself before commercialising — status can change and this page is a summary, not legal advice.
We are not aware of state controlled-substance scheduling of corydalis alkaloids as of August 2026, and state kratom acts do not reach corydalis-only products by their terms. States legislate independently and quickly, so confirm current law in every market you sell into. Our state page is a starting point.
On the structural analysis, we do not see a pathway — it is not a close variant of the Schedule I and II families the provision has been applied to. But analogue determinations are fact-specific and depend heavily on marketing conduct, which is within your control. Marketing guidance.
Controlled-substance licensing does not arise for an unscheduled substance. Other requirements may well apply to you as a manufacturer or seller of consumable products — food establishment permits, facility registration, labelling rules — depending on your state and your role. That is a question for your counsel, not for an ingredient supplier.
No. We are a manufacturer, not a law firm, and nothing on this site is legal advice. What we can do is set out the regulatory landscape and point you to the primary sources so your counsel starts from something substantive. The summary is written for exactly that.