What is Corydalis yanhusuo?
Corydalis yanhusuo is a small flowering plant in the poppy family (Papaveraceae) native to eastern China, where its tuber-like rhizome has been dried, sliced and used as a botanical ingredient for well over a thousand years. It is one of the most widely used roots in traditional Chinese herbal practice, typically referred to as yan hu suo. In the United States, corydalis extract has been sold as a dietary ingredient for decades and appears in hundreds of supplement formulas.
The rhizome is rich in isoquinoline alkaloids. The most famous is tetrahydropalmatine (THP), and the majority of research on corydalis focuses on it. But the plant contains dozens of related molecules, including protopine, corydaline, dehydrocorydaline and a family of hydroxylated compounds. 13-OH is one of those distinct hydroxylated alkaloids, and it is the compound Tempo’s corydalis extract is standardized for.
Two things matter up front. First, corydalis is not related to kratom. Kratom (Mitragyna speciosa) is a tree in the coffee family whose leaf alkaloids include mitragynine and 7-hydroxymitragynine. Corydalis is a different plant, a different family, and a different alkaloid chemistry. Second, corydalis and its extracts are not scheduled substances under federal law. The DEA’s August 2026 temporary scheduling order covers concentrated 7-hydroxymitragynine only. It says nothing about corydalis, because corydalis has nothing to do with 7-OH.
13-OH vs. THP: distinct molecules, separated by HPLC
Generic corydalis extracts on the market are usually labeled for total alkaloids or for THP percentage. That’s fine for a general botanical, but it tells you nothing about 13-OH content, which can vary widely from harvest to harvest and from extraction method to extraction method.
The extract used in Tempo comes from Corydalis Labs, which standardizes specifically for 13-OH. The key tool is high-performance liquid chromatography (HPLC). In an HPLC run, the extract is dissolved and pushed under pressure through a column packed with fine particles. Different molecules interact with the column differently and exit at different times, called retention times. Because 13-OH and THP have different structures (13-OH carries an additional hydroxyl group), they elute at clearly separate retention times and produce separate peaks on the chromatogram. The area under each peak, compared against a reference standard, gives a quantified concentration.
This is why we can say two things with confidence on every lot:
- 13-OH and THP are distinct molecules, not a labeling difference or a marketing name for the same thing.
- The 13-OH content per tablet is quantified and appears on the certificate of analysis alongside mitragynine and 7-OH.
A note on naming
You’ll see “13-OH” written a few ways online: 13-OH corydalis, 13-hydroxy corydalis, or simply 13-OH tablets. They refer to the same standardized ingredient. If a product says “corydalis” without stating a 13-OH amount, it is almost certainly a THP-standardized or total-alkaloid extract rather than the 13-OH ingredient used here.
Why 13-OH pairs with kratom extract
The traditional way to make a kratom extract product feel stronger is to raise the alkaloid number. That approach hit a wall in 2026: concentrated 7-OH products were temporarily scheduled, and high-mitragynine extracts bring what our testers consistently describe as sensory harshness: the scratchy, edgy, slightly nauseous quality that shows up when you push leaf extract too far.
Tempo takes a different route. Rather than maximizing mitragynine, its 250 mg kratom alkaloid blend pairs a moderate, standardized dose (20 mg mitragynine per tablet) with 30 mg of 13-OH corydalis extract. The positioning, which comes directly from Corydalis Labs’ formulation guidance, is that 13-OH lets a blend use less mitragynine while feeling fuller, with reduced sensory harshness. In practice, our early testers describe a Tempo tablet as more rounded and complete than a comparable amount of kratom extract on its own, and noticeably smoother on the way in.
Three practical consequences follow:
- Lower alkaloid load per serving. A half tablet is 125 mg of the blend, about 10 mg of mitragynine, which is on the modest end for an extract product. That makes the cross-score genuinely useful rather than decorative.
- Predictable feel. Because both ingredients are standardized and locked in a fixed ratio, Mixed Berry today feels like Mixed Berry next month. That consistency is the hardest thing to get from loose kratom powder.
- Compliance headroom. The formula doesn’t depend on 7-OH for its effect, so there’s no temptation to push naturally occurring 7-OH toward the federal limit. Every lot is verified under the 1.00 mg per unit threshold with margin to spare. See our 7-OH alternatives guide for the full regulatory picture.
How much 13-OH is in a Tempo tablet?
Corydalis Labs recommends 25–40 mg of 13-OH per serving when it is blended with other botanicals. Tempo uses 30 mg per tablet (of the 250 mg blend), so a full tablet sits inside that range and a half tablet delivers 15 mg. We settled on a mid-range amount deliberately: enough for the pairing to do its work, without letting corydalis dominate the profile. If you want to see exactly what a given lot contains, every COA lists the measured corydalis content next to mitragynine.
| Per serving | Kratom alkaloid blend | Mitragynine | 13-OH corydalis extract | 7-OH |
|---|---|---|---|---|
| Half tablet | 125 mg | 10 mg | 15 mg | < 0.50 mg (verified) |
| Full tablet | 250 mg | 20 mg | 30 mg | < 1.00 mg (verified) |
Sourcing: why Corydalis Labs
We chose Corydalis Labs as our supplier for three reasons. They standardize for 13-OH rather than THP, which is the whole point of the ingredient. They provide lot-level documentation, including identity testing on the raw Corydalis yanhusuo rhizome and HPLC quantification on the finished extract, so we can trace every tablet back to a specific botanical lot. And their formulation guidance (the 25–40 mg range, the pairing rationale) is grounded in their own work with the ingredient rather than borrowed from THP literature.
The extract then goes to our cGMP co-packer in Saint Petersburg, Florida, where it is blended with the kratom extract, compressed into cross-scored tablets, flavored, and sent out for independent testing. Read more about that pipeline on our quality and compliance page and the science behind Tempo.
Safety, interactions and who should not use it
Corydalis has a long history of use and a wide margin of typical use, but it is a pharmacologically active botanical and deserves the same respect as kratom. A few honest notes:
- Start with half a tablet. The pairing is designed to feel fuller than the mitragynine number suggests. Don’t judge it by your usual kratom serving.
- Drowsiness. Corydalis alkaloids can be calming. Do not drive or operate machinery after use, and be careful combining Tempo with anything else that makes you sleepy.
- Medications. If you take prescription medication, particularly anything affecting the central nervous system, blood pressure or liver enzymes, talk to your physician before using corydalis or kratom.
- Pregnancy and nursing. Do not use.
- Under 21. Tempo is strictly 21+.
- Habit-forming potential. Kratom products may be habit-forming. Use Tempo occasionally and intentionally, and space servings at least 6 hours apart.
Dialed makes no claims that corydalis or kratom treat, cure or prevent any condition. Everything on this page describes the ingredient, its sourcing and how people describe the experience, not a medical outcome.
Try 13-OH corydalis kratom tablets
Tempo is the simplest way to try a 13-OH corydalis kratom tablet: a fixed, verified ratio in a flavored, cross-scored tablet. Start with the 1ct sachet ($7.99) to pick a flavor, or go straight to the 4ct blister ($24.99) for the best per-tablet price. Both are in the shop, and if you want the deeper reading, the Dialed blog covers corydalis, kratom and the 7-OH transition in more detail.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Not for use by anyone under 21. Keep out of reach of children. Do not use if pregnant or nursing. Consult a physician before use if you have a medical condition or take medication. Do not operate a vehicle or heavy machinery after use. Kratom products may be habit-forming; use responsibly.