Senna pods usually contain more sennosides than leaves, and both vary with growing conditions and grade. For medicinal use, the minimum content is set by the pharmacopoeia your market follows, such as the European or US pharmacopoeia.
For other uses, such as herbal teas, there is no universal figure. Agree a range with your supplier based on tests, and check whether your market limits the content.
How sennoside content is expressed
Sennosides A and B are the main compounds of interest. Pharmacopoeias usually express the result as total hydroxyanthracene glycosides, calculated as one named sennoside, by a set method. Other labs report sennosides A and B by HPLC. The two approaches can give different numbers for the same lot.
Always state the method and how the result is expressed. Otherwise two certificates cannot be compared.
What affects the level
- Plant part: pods and leaves differ, and grades of each differ.
- Harvest timing: leaves picked at different stages vary.
- Drying: slow or damp drying can lower content and cause mould.
- Storage: content falls over time, especially in warm, damp stores.
- Stems and foreign matter: they dilute the product.
- Adulteration with other Cassia species or leaves.
Use and regulation set the target
Your regulator, not the supplier, decides what is allowed. Check before you place an order.
- Medicines: follow the current monograph for leaf or pod and the method it specifies. Check the latest edition, as monographs are revised.
- Extract production: the extract maker will set its own raw material minimum.
- Herbal teas: check whether senna is permitted in teas in your market and whether content or warnings are regulated.
- Food supplements: the EU has restricted certain hydroxyanthracene derivatives in food. Confirm the current rules before use.
What to write in the spec
See botanical identity testing and heavy metal limits for herbs for the safety side.
- Botanical name, plant part, grade and form.
- Minimum sennoside content, method and basis, matched to your use.
- Moisture, foreign organic matter and stem limits.
- Microbiology, heavy metals and pesticide residues for your market.
- Identity test, for example HPTLC against reference material.
Leaves versus pods
Leaves and pods are traded and priced separately. Pods are often sold to extract makers and pharmaceutical buyers because of their higher content. Leaves are used in teas, powders and extraction. Some buyers specify graded whole leaves, others accept broken leaf for milling.
Do not mix leaves and pods in one lot unless you have agreed a ratio. A blended lot gives an average result that is hard to check and easy to dispute.
Approve each grade on a tested sample, and retest the pre-shipment sample. Content can fall in long storage, so ask when the lot was harvested.
How we help
We have senna leaves and pods tested at NABL-accredited labs by the method your market requires, and check that the lot shipped matches the lot tested. Begin with a free sourcing review.