Alkaloid glossary

13-OH Corydalis Yanhusuo

Also: 13-OH; "13"

The compound this site is about: a hydroxylated alkaloid derived from Corydalis yanhusuo rhizome, related to that plant’s principal alkaloid tetrahydropalmatine. Some suppliers write it "13-OH THP"; the botanical name is the more precise description. Used by formulators as a synergist at 25–40 mg per serving. It is an isoquinoline alkaloid, is not derived from kratom, and as of August 2026 does not appear on the United States federal controlled substance schedules. Full reference.

7-OH

Also: 7-hydroxymitragynine

An oxidation product of mitragynine found in trace amounts in the kratom leaf and produced at scale for concentrated products. DEA filed a notice of intent to temporarily place it in Schedule I in July 2026, and several states scheduled it earlier. Frequently confused with 13-OH because of the naming convention; the two are unrelated. Comparison.

Alkaloid

A naturally occurring nitrogen-containing organic compound produced by plants. Caffeine, nicotine, morphine, mitragynine, and tetrahydropalmatine are all alkaloids. The term describes a broad chemical category, not a level of potency or a legal status.

Assay

The measured amount of a specified compound in a material, usually as a percentage. Our 13-OH typically assays at 93–98% active. An assay figure means little without a stated method — ask what analysis produced it.

Certificate of analysis (COA)

A document reporting laboratory results for a specific production lot — typically identity, assay, and where required contaminant testing. A useful certificate names the lot, the date, the method, and the result. What ours include.

cGMP

Also: current good manufacturing practice

The manufacturing quality standard set out for dietary supplements at 21 CFR Part 111, covering process control, documentation, testing, and record-keeping. We manufacture under it in our own facility.

Chromatography

Also: HPLC, high-performance liquid chromatography

A laboratory technique that separates the components of a mixture so each can be identified and measured. It is how 13-OH is distinguished from its parent alkaloid — the two elute at 18.8 and 15.0 minutes respectively. Our method.

Controlled Substances Act (CSA)

Also: 21 U.S.C. §801 et seq.

The federal statute establishing the drug scheduling framework in the United States. Substances are controlled only when placed in a schedule by Congress or through DEA rulemaking. The schedules themselves are published at 21 C.F.R. Part 1308. How it applies here.

Controlled substance analogue

Also: the Analogue Act, 21 U.S.C. §802(32)

A provision allowing an unscheduled substance to be treated as Schedule I when it is substantially similar in chemical structure to a Schedule I or II substance and has or is represented to have a substantially similar effect, and is intended for human consumption. Determinations are fact-specific and turn heavily on how a product is marketed.

Corydaline

One of the alkaloids reported in Corydalis yanhusuo rhizome. Distinct from tetrahydropalmatine and from 13-OH.

Corydalis yanhusuo

Also: yan hu suo; Rhizoma Corydalis; C. turtschaninovii

A flowering plant in the poppy family whose dried rhizome has centuries of documented traditional use in eastern Asia. The botanical source of tetrahydropalmatine and therefore of 13-OH. The plant page.

DEA

Also: Drug Enforcement Administration

The federal agency that administers the controlled substance schedules and publishes scheduling actions. Its consolidated listing of controlled substances and regulated chemicals is commonly called the Orange Book.

DHCB

Also: dehydrocorybulbine

Another alkaloid reported in Corydalis rhizome. Some sources name it as the plant's primary active and others name tetrahydropalmatine; both are present, and the emphasis usually reflects what a given product is standardised to.

Indole alkaloid

A structural family of alkaloids built on an indole core. Mitragynine and 7-OH belong to it. Corydalis alkaloids do not — they are isoquinolines, a separate family.

Isoquinoline alkaloid

A structural family of alkaloids built on an isoquinoline core. Tetrahydropalmatine and 13-OH belong to it, as do many poppy-family alkaloids. Distinct from the indole alkaloids of the kratom leaf.

Kanna

Also: Sceletium tortuosum; mesembrine

A South African succulent used in botanical formulations, commonly combined with kava and 13-OH in kratom-free social products. Not derived from kratom and not within the scope of state kratom acts.

Kava

Also: Piper methysticum; kavalactones

A Pacific Island plant whose root is used in traditional and modern relaxation beverages. Its active constituents are kavalactones. Frequently the base of kratom-free formulations. Kratom-free builds.

Kratom

Also: Mitragyna speciosa

A tree in the coffee family native to Southeast Asia, whose leaf contains mitragynine and related indole alkaloids. State kratom acts define their scope around this plant and its alkaloids. Corydalis products fall outside those definitions. State detail.

Kratom Consumer Protection Act (KCPA)

The general name for state statutes regulating kratom products — typically imposing age restrictions, labelling requirements, and registration or permitting. Each state's version differs. All define their scope around Mitragyna speciosa.

List I / List II chemicals

Chemicals regulated by DEA because of their use in manufacturing controlled substances. They are subject to registration and record-keeping requirements but are not themselves controlled substances. Neither 13-OH nor corydalis extract appears on these lists.

MGM-15

Also: Oxonol

A semi-synthetic compound related to mitragynine chemistry, marketed for a period as a 7-OH alternative. Named in DEA notices of intent in July 2026. What happened.

MIT

Also: mitragynine

Shorthand for mitragynine, the principal alkaloid of the kratom leaf and the primary active in most products in this category.

MIT + 13

Industry shorthand for a mitragynine product with 13-OH blended in, typically at 25–40 mg per serving. The most common application of 13-OH. Full explanation.

Mitragynine pseudoindoxyl

Also: pseudo

A rearrangement product of mitragynine, marketed for a period as a 7-OH alternative. Named in DEA notices of intent in July 2026. What happened.

Notice of intent

A published notice that DEA intends to take a scheduling action, typically preceding a temporary scheduling order. It signals that a substance is on a path toward control rather than that control has already taken effect — but the market usually reacts immediately. Current notices.

Piperine

A black pepper constituent used as an absorption enhancer. It increases duration and perceived effect in a formulation and noticeably degrades taste — a real trade-off in flavoured liquid formats.

Protopine

An alkaloid reported in Corydalis rhizome and in other poppy-family plants. Distinct from tetrahydropalmatine.

Salts and isomers principle

The rule under which control of a scheduled substance extends to its salts, isomers, and salts of isomers where those forms are possible within the chemical designation. It operates only where a parent compound is itself scheduled — which is why an unscheduled parent means no derivative capture. How this applies.

Standardisation

Processing a botanical material so a specified constituent is present at a consistent, stated level. Without standardisation and testing, "extract" describes a process rather than a product. Our material is standardised on 13-OH and reported lot by lot.

Synergist

An ingredient whose value comes from what it contributes alongside other actives rather than on its own. 13-OH is a synergist: subtle in isolation at commercial inclusion rates, substantial in a blend. What it contributes.

THP

Also: tetrahydropalmatine; l-THP; rotundine

The principal alkaloid of Corydalis yanhusuo and the parent compound of 13-OH. An isoquinoline alkaloid, characterised in the literature for decades, discussed in terms of dopaminergic rather than opioid activity. Full page.

Temporary scheduling

A mechanism allowing DEA to place a substance in Schedule I on an expedited basis pending fuller review. Temporary orders have effect for a defined period and may be extended or made permanent.