How to read an astragalus extract specification, line by line
What we settle before an astragalus specification sheet goes out. Almost every enquiry opens with one number, usually polysaccharides 50%, while the sheet has to answer a question the buyer has not asked: which astragaloside IV grade sits behind it. So we confirm the polysaccharide grade (20%, 40% or 50% by UV-VIS), whether the label claim rests on polysaccharides or astragaloside IV (0.3% or 0.5% by HPLC), and the mesh (80 as standard, 100 on request). We then attach the latest lot COA from our manufacturing partner, a GMP-audited factory we represent as authorised export sales: the sheet states limits, the COA states results.
An astragalus extract specification is longer than it looks. Most buyers read only the polysaccharide line, because that is the number printed on every finished-product label they have seen. This article reads the sheet in the order that matters; the commercial side is in our astragalus sourcing guide and the format decisions in our astragalus applications breakdown.
What the two assays actually measure
Polysaccharides 20%, 40% or 50% is a bulk measurement read on a UV-VIS spectrophotometer: the total polysaccharide fraction is quantified colorimetrically as a percentage of powder mass. It is a family figure, not a single molecule: two suppliers can both quote 50% and ship material that behaves differently in a capsule.
Astragaloside IV 0.3% or 0.5% is the opposite kind of measurement: one named compound quantified by HPLC as a distinct peak against a reference standard, which says something about the root that went into the extract rather than about total carbohydrate load. A polysaccharide figure can be reached by blending in maltodextrin or extracting a lower-grade root hard; the astragaloside IV line is much harder to move that way, which is why we quote both together.
Choosing between the grades
The standard production grade is published at three polysaccharide levels with two astragaloside IV options; the mapping below is a starting point, not a regulatory classification.
| Polysaccharides (UV-VIS) | Astragaloside IV (HPLC) | Where we usually see it |
|---|---|---|
| 20% | 0.3% | Tea and beverage concentrates, multi-botanical blends |
| 40% | 0.3% | Multi-ingredient capsules and functional powders |
| 50% | 0.5% | Single-ingredient capsules that print the polysaccharide figure |
If your label declares a polysaccharide percentage, buy the matching grade with margin, because the COA result will sit above or below the nominal figure and your label tolerance has to absorb that. If it declares astragaloside IV, 0.5% is the usual choice and polysaccharides becomes a secondary line. Mixing the two bases across a range is the most common source of label mismatch we see.
The physical lines: mesh, moisture and ash
Three physical lines decide whether the powder runs on your line:
- Particle size. 80 mesh standard, 100 mesh on request, both verified by sieve analysis. Dry blends flow at the standard mesh without a separate milling step; 100 mesh suits finer dispersion in beverage bases.
- Loss on drying. 5.0% or less, determined gravimetrically after oven drying. This is free moisture, and it governs shelf life in unopened packing; a lot at 3.8% has more headroom than one at 4.9%.
- Total ash. 5.0% or less, determined gravimetrically after muffling. Ash is the inorganic residue, and the limit keeps mineral load from masking a weak extract.
Appearance — light brown to yellow-brown fine powder, characteristic odour, slightly sweet taste — is checked against the retained sample, not the sheet. The carrier line matters too: our standard is a pure extract with no excipient, with maltodextrin on request. Carrier changes potency per gram, so it belongs in the quotation, not a footnote.
Packing, shelf life and what the batch COA adds
| Line | Standard |
|---|---|
| Packing | 25 kg fibre drum, double polyethylene liner |
| Sample packing | 1 kg and 5 kg foil bags |
| Shelf life | 24 months in unopened original packing |
| Storage | Cool, dry, away from direct sunlight |
| Lead time | About 2 days in stock; 3–5 working days for bulk after deposit |
The sheet states limits; the COA states results. On a typical 50% lot we see polysaccharides 50.4% by UV-VIS, astragaloside IV 0.52% by HPLC, loss on drying 3.8% and total ash 3.1%, both gravimetric, lead below 1 ppm, arsenic below 0.5 ppm, cadmium below 0.3 ppm and mercury below 0.05 ppm, total plate count below 1,000 cfu/g, and E. coli and Salmonella negative. Ask for the COA that would ship with your order, not a generic sample.
We consolidate in Xi'an and move to Shenzhen in about three days; air freight takes about six days to major U.S. and EU airports, sea freight 18–25 days. If your production date is fixed, read lead time and transit together.
How we read a competitor sheet
When a buyer sends another supplier's sheet, we read four things: the assay basis (are both lines present, on the same basis as ours), the grade pairing (50% with 0.3% astragaloside IV is not 50% with 0.5%), the physical limits, and the documentation — usually decisive, because a supplier who cannot send a lot COA before the order will not send a useful one after it.
The specification is a promise about a grade; the certificate of analysis is evidence about a lot. A purchase decision needs both.
We supply astragalus extract as a food ingredient. We make no therapeutic claims for it, and structure/function wording and label compliance rest with the buyer. What we can do is keep specification and lot documentation aligned, so the material you receive matches the sheet you approved.
Frequently asked questions
What is astragalus extract standardised to?
Polysaccharides at 20%, 40% or 50% by UV-VIS, and astragaloside IV at 0.3% or 0.5% by HPLC. The first is a bulk family measurement; the second is a single named compound. We quote both, because either alone can describe a material your process will not recognise.
Why does the specification carry two assay lines?
Polysaccharides describes the total carbohydrate fraction and can be influenced by carrier or extraction intensity; astragaloside IV is a specific HPLC marker and much harder to inflate. Read both together to tell a high-grade extract from a diluted one.
What packing and shelf life does astragalus extract come in?
A 25 kg fibre drum with double polyethylene liner, plus 1 kg and 5 kg foil bags for samples and pilot runs. Shelf life is 24 months unopened, stored cool, dry, away from sunlight. Every lot ships with a batch COA.
Related reading
- Where astragalus extract fits: four formula categories
- Astragalus extract: a sourcing guide for immune-support formulas
Related: Astragalus Polysaccharides (APS) — full specification, grades and documentation. Also under the same QC standard: Poria Cocos Extract and Milk Thistle Extract.