Two quotes for “senna extract” can describe very different materials — different plant part, different sennoside grade, different assay method. This guide sets out the parameters a B2B buyer should fix on the specification before comparing price.
Senna is one of the most widely traded stimulant-laxative botanicals in the world, and almost all of it originates in India. Because the active fraction — the sennosides — can be declared against very different assay methods and grades, two quotes for “senna extract” can describe materially different materials. This guide sets out the parameters a B2B buyer should pin down on the specification before comparing price.
1. Fix the Botanical and Plant Part First
Commercial senna is Senna alexandrina Mill. (synonym Cassia angustifolia Vahl), the Tinnevelly or Indian senna grown mainly in Tamil Nadu, Gujarat and Rajasthan. Confirm both the species and whether the extract is made from leaf, pod (fruit), or a leaf/pod blend — the sennoside profile differs between them (see leaf vs pod extract). A specification that names only “senna” leaves room for lower-cost Cassia-species substitution.
2. Choose a Sennoside Grade — and the Method Behind It
Senna extract is standardised to a sennoside percentage. The number is only meaningful once you know how it was measured: a UV-spectrophotometric assay (calculated as sennoside B) and an HPLC assay of sennosides A&B do not read the same on the same material. Always require the method next to the figure (see UV vs HPLC).
| Grade | Typical sennoside content | Common use |
|---|---|---|
| Traditional / tea-cut | Native (leaf, not concentrated) | Herbal teas, infusions |
| Standard 20% | 20% (calc. as sennoside B, UV) | Supplements, capsules |
| Concentrated 40% | 40% (UV) | Tablets, dose-controlled |
| High-potency 60% | 60% (UV) | Pharma-grade laxatives |
| Sennosides A&B by HPLC | Defined A&B, HPLC | Pharmacopoeial / tight spec |
Buyer tip: a “60% senna” by UV is not automatically stronger than a “40%” by HPLC. Compare grades only when the assay method and the reference standard (sennoside B vs A&B) are the same.
3. Lock the Quality & Safety Panel
Beyond potency, the specification should carry the safety parameters that gate clearance and shelf life:
- Ethylene oxide (ETO) — non-ETO / non-irradiated, pre-tested on request; the key EU trigger (see regulatory guide).
- Heavy metals — Pb, As, Cd, Hg by ICP-MS.
- Pesticide residues — to destination MRLs.
- Microbiology — total plate count, yeast & mould, pathogens absent.
- Loss on drying / residual solvent — for water or hydro-alcoholic extraction.
4. Read the CoA Against the Spec
A batch Certificate of Analysis should reference a named specification (ours is SVB-SPEC-SN-01), report actual results with methods, and match the declared grade. Watch for a sennoside figure quoted without a method, a species named only as “Cassia”, or microbial/heavy-metal lines shown as “complies” without values.
To go deeper on origin and processing, read the senna sourcing guide; to specify the finished material, see the Senna Extract product page.
Specify Senna Extract With Confidence
Sennoside grade · UV or HPLC assay · leaf or pod · non-ETO · ICP-MS metals · batch CoA