Reviewed August 2026 by the Corydalis Labs Technical Team. How we research and review.
The problem this solves
13-OH is a derivative of a cheaper, more widely available compound. In a market where buyers cannot easily tell the difference, that creates an obvious temptation — and material sold under one name that turns out to be another is a documented problem in adjacent categories.
The defence is not a supplier's assurance. It is a method that produces a result a third party can reproduce.
The method
We use reverse-phase high-performance liquid chromatography with UV detection. Under our conditions, tetrahydropalmatine and 13-OH resolve as two clearly separated peaks:
- Tetrahydropalmatine — retention time 15.0 minutes
- 13-OH — retention time 18.8 minutes
A 3.8 minute separation on this scale is unambiguous. A sample that is actually THP cannot present as the derivative, and a sample containing both shows two peaks rather than one.
What you receive
Certificate of analysis
Identity and assay for your specific lot, lot-coded to match your container. Material typically runs 93–98% active.
Chromatogram on request
The actual trace for your lot, so your technical team can see the separation rather than read a number.
Method parameters
Our conditions, shared on request, so your own lab can set up quickly instead of developing a method.
Verifying independently
We would rather you did than took our word for it. A supplier that discourages third-party testing is telling you something about itself.
- Send material to any competent analytical lab. The separation works under standard reverse-phase conditions; this is not exotic analysis.
- Ask us for our parameters so your lab is not starting from scratch. We will send them.
- Compare across lots. Consistency lot to lot is what actually matters in production, and it is visible in the certificates.
What a good certificate should tell you
Identity of the compound, assay as a percentage, the lot code, and the date. If a certificate names a compound without stating how identity was established, it is telling you less than it appears to. Ask what method produced the result.
Common questions
Yes. Email sales@corydalislabs.com and we will send a representative certificate for current material, along with our method parameters if your lab wants them.
93–98% active. The exact figure for your lot appears on its certificate.
The lot code on the certificate matches the code on your container. If they do not match, tell us immediately. If you want to close the loop entirely, send a retain sample to an independent lab and compare.
Identity and assay are standard on every lot; contaminant panels are available. Tell us what your specification requires and we will confirm what we can provide.