Reviewed August 2026 by the Corydalis Labs Technical Team. How we research and review.
What this covers, and what it does not
Read this first
This page summarises how we understand 13-OH and Corydalis extract to sit under the federal Controlled Substances Act as of August 2026. It is not legal advice, it is not an opinion you may rely on, and Corydalis Labs is not a law firm. It is written to give your counsel a substantive starting point with the primary sources identified, so their review begins from something better than a marketing page.
It covers controlled-substance status only. It does not address food and supplement law, labelling requirements, state licensing, or advertising regulation — all of which may apply to a finished product and none of which are answered by "it is not a controlled substance."
1 · Scheduling status
Finding: not listed.
Neither 13-OH Corydalis Yanhusuo, nor its parent tetrahydropalmatine, nor Corydalis rhizome extract, nor their salts appear in the federal controlled substance schedules at 21 C.F.R. Part 1308, or on DEA's List I or List II chemical lists.
They are also not reached by the class-based schedule entries. Those entries cover defined structural families — tetrahydrocannabinols, tryptamines, phenethylamines, fentanyl-related substances, cathinones, anabolic steroids. None of them extends to isoquinoline alkaloids, which is the family tetrahydropalmatine and its derivatives belong to.
Source to review: 21 C.F.R. Part 1308; DEA's consolidated lists of scheduling actions, controlled substances and regulated chemicals.
2 · The salts-and-isomers principle
Finding: no derivative capture.
Schedule entries generally extend control to a substance's salts, isomers, and salts of isomers where such forms are possible within the chemical designation. This is the mechanism by which derivatives of scheduled compounds are controlled without being individually listed.
The mechanism operates only from a listed parent. Because tetrahydropalmatine is not scheduled, there is no listed parent from which control could extend to 13-OH. The absence is structural rather than an oversight or a matter of enforcement discretion.
This is the analytical difference from 7-hydroxymitragynine, which is a derivative of mitragynine — chemistry already the subject of regulatory attention — and which moved when that chemistry moved.
Source to review: the salts, isomers, and salts of isomers language in 21 C.F.R. §1308.11 and the parallel provisions in the following sections.
3 · The controlled substance analogue provision
Finding: no evident pathway on the structural analysis.
Under 21 U.S.C. §802(32), an unscheduled substance may be treated as Schedule I where it is (a) substantially similar in chemical structure to a Schedule I or II substance, (b) has, or is represented or intended to have, a substantially similar stimulant, depressant, or hallucinogenic effect, and (c) is intended for human consumption.
Courts have applied the provision principally to close structural variants of established Schedule I and II families. 13-OH is an isoquinoline alkaloid derived from a plant with a long history of traditional use; it is not a structural variant of the families to which the provision has been applied.
The important caveat: the statute directs attention to marketing, advertising, and labelling in assessing whether a substance is intended for human consumption, and the "represented to have" limb turns on what a seller says. Marketing conduct is therefore part of the analysis, and it is the part within your control. A structurally clean compound marketed as a substitute for a controlled substance is a materially different case from the same compound marketed as a formulation ingredient.
Source to review: 21 U.S.C. §802(32), including the factors at §802(32)(B).
4 · The plant extract
Finding: not listed.
Corydalis rhizome extract does not appear on the schedules or the chemical lists, and we have not identified an umbrella listing that would incidentally capture it. Its isolated alkaloid salts are not controlled by virtue of being salts, because the parent alkaloid is itself unlisted.
5 · What this does not tell you
Deliberately restating the boundary, because this is where companies get into trouble:
- State law is separate. States schedule substances independently and often move faster than the federal government. Our state page.
- Food and supplement law is separate. Whether an ingredient may lawfully be used in a consumable product, and under what conditions, is a different question from whether it is a controlled substance.
- Marketing law is separate — and is where enforcement in adjacent categories has most often landed. Marketing guidance.
- Status changes. Agencies act. We maintain a tracker and update this page when something moves.
What to take to your lawyer
A short list that will make their review faster and cheaper:
- The compound identity — 13-OH Corydalis Yanhusuo, an isoquinoline alkaloid derived from Corydalis yanhusuo.
- Your finished formula, including every other active. The analysis is about your product, not our ingredient.
- Your draft label and marketing copy. This is the part that most affects risk and the part lawyers most often are not shown.
- The markets you intend to sell into, so state law can be checked.
- Our certificate of analysis for the material, so identity is documented rather than assumed.