In short: These three grades are not interchangeable, because they are priced and verified on different bases. 5% and 7% withanolides are marker-standardised grades measured by HPLC or UV — you buy a guaranteed withanolide level. 10:1 is an extract ratio measured by TLC — you buy a botanical-to-extract relationship, not a guaranteed marker content. If your label, dosage form or market claim names a withanolide percentage, buy a standardised grade; a ratio extract will not support that claim.
The two different things you are actually buying
A specification answers one of two questions: how much active marker is present (standardised grade) or how concentrated the botanical is relative to raw herb (ratio extract). Confusing them is the most expensive mistake in ashwagandha sourcing, because the price drivers differ entirely.
| Specification type | Example | Method | What is guaranteed | What is NOT guaranteed |
|---|---|---|---|---|
| Marker-standardised | Withanolides ≥ 7% | HPLC or UV | A stated minimum withanolide content in the finished powder | Ratio to raw root; total soluble solids |
| Ratio extract | 10:1 | TLC (identity) | Approximate concentration relationship to raw herb | Any specific withanolide percentage |
| Raw milled root | Root powder | Identity only | Identity and cleanliness | Standardised marker content |
7% vs 5%: when the higher grade actually pays off
Higher standardisation reduces the amount of powder you must dose to reach a target withanolide intake. That matters when capsule size, taste or excipient load is a constraint — and it matters less when you have formulation headroom.
| Grade | Withanolide level | Powder required per 30 mg withanolides | Notes |
|---|---|---|---|
| Standardised 7% | 7.0% | ≈ 429 mg | Best fit for compact capsules |
| Standardised 5% | 5.0% | ≈ 600 mg | Common in larger capsule / sachet formats |
| Standardised 1.5% | 1.5% | ≈ 2,000 mg | Practical only in bulk powder formats |
| Ratio 10:1 | Not guaranteed | Cannot be calculated | Do not use where a withanolide claim is made |
The arithmetic is linear: dividing your target withanolide amount by the assay percentage gives the powder mass. Ask the supplier for the measured result, not just the specification limit — a 7% grade supplied at 7.05% behaves differently from one supplied at 7.6%.
Why UV and HPLC give different numbers on the same material
UV spectroscopy measures total absorbance at a given wavelength; HPLC separates and quantifies individual withanolides against a reference standard. On the same lot, a UV result typically reads higher than an HPLC result. Neither is “wrong” — but a purchase agreement naming HPLC is not satisfied by a UV certificate, and label claims must match the method used to substantiate them. Always state the method, the reference standard and the calculation basis in the specification.
Root vs root-and-leaf: a separate decision from assay
Plant part is an independent variable from withanolide percentage. Root material is the conventional choice for standardised grades; root-and-leaf material can reach a similar assay while changing the soluble-solids profile and the cost base. Decide plant part first, then choose the assay level — otherwise you will compare quotes that are not comparable.
What a complete 7% grade offer should include
- Specification: withanolides ≥ 7.0%, method stated (HPLC or UV), calculation basis stated
- Batch-level COA with measured result, batch number, manufacture and expiry dates
- Particle size and mesh pass rate (capsule filling and blend uniformity depend on it)
- Loss on drying and ash, plus heavy metals (Pb, As, Cd, Hg) and microbiological results with methods
- Residual solvent statement (water vs ethanol extraction changes the declaration)
- Allergen, non-GMO, irradiation and BSE/TSE statements if your market requires them
Specification block template
| Parameter | Example entry | Why the line is needed |
|---|---|---|
| Grade / standardisation basis | Withanolides 7% (or the 5% or 10:1 ratio grade you selected) | The grade decides what is being measured and what you may declare |
| Marker value | A minimum, not a range, unless a range is genuinely required | A minimum can be enforced; a range invites dispute at its lower bound |
| Analytical method | As required by your label or dossier — stated explicitly | Different methods return different figures on the same material |
| Botanical source and plant part | Withania somnifera, with the part used named | Trade names do not define the analytical basis |
| Physical form and solvent | Mesh pass rate plus extraction solvent with a residual-solvent declaration | Sets flow, blend behaviour and residue compliance together |
FAQ
Is 7% withanolides better than 5%?
It is more concentrated, not automatically better. Choose 7% when you need to fit a target withanolide dose into a small capsule or reduce powder load; choose 5% when you have formulation headroom and want a lower cost per kilogram.
What does 10:1 mean, and when should I choose it?
10:1 means roughly ten parts raw herb to one part extract, verified by identity testing (TLC) rather than a marker assay. Choose it for traditional or non-standardised positioning where no withanolide percentage is claimed.
Why is a UV result higher than an HPLC result on the same material?
UV measures total absorbance without separating individual withanolides, so interfering compounds can inflate the reading. HPLC quantifies specific withanolides against a reference standard. Agree the method before ordering.
How do I convert between a 5% and a 7% grade in my formulation?
Divide your target withanolide amount by the assay percentage. For 30 mg withanolides: 30 ÷ 0.07 ≈ 429 mg of 7% powder, or 30 ÷ 0.05 = 600 mg of 5% powder. Recalculate on the measured result, not the nominal specification.
Should withanolide content be measured on a dried basis?
It should be stated explicitly, because moisture shifts the arithmetic. Ask for the calculation basis in writing; comparing an as-is result against an anhydrous specification is a common source of dispute.
Does plant part (root vs root-and-leaf) affect the assay?
It affects the matrix, soluble solids and cost base more than the headline assay, since standardisation can bring either material to a stated percentage. Fix plant part before comparing prices.
What documentation should come with each batch?
A batch-level COA covering assay with method, physical and chemical data, heavy metals, microbiology and residual solvents — plus a statement of the calculation basis and named QC signatures.
Can I substitute a 10:1 extract for a 7% grade to reduce cost?
Only if you drop the withanolide claim. Substituting without changing the label creates a substantiation gap that regulators and retail customers can both challenge.
Compare standardised grades with batch-level COAs, or send us your target specification and destination market.
Representative specification routes
- Ashwagandha Extract Powder 7% Withanolides
- Ashwagandha Root Extract Powder 5% Withanolides
- Ashwagandha Root Extract Powder 10:1
Confirm the offered grade, analytical basis and current batch documentation before qualification.