Buying guides27 September 20261 min read
Which documents to request when buying bulk extracts in the EU
A practical checklist of the documents purchasing and quality teams should request before approving a bulk extract and each lot.
Ratio vs standardised extracts: how to compare specifications
A 10:1 extract and a 95% extract describe different things. How to read each specification, compare offers fairly and choose the right one for your formula.
Bulk Extracts team2 min read
When two suppliers quote "reishi extract", they may be offering very different materials. One lists 10:1, the other 30% polysaccharides. Both descriptions can be correct, but they answer different questions, and comparing them on price per kilo alone leads to poor buying decisions.
What a ratio (10:1) tells you
A ratio, also called the drug-extract ratio (DER), states how much dried plant material was used to make one part of extract. 10:1 means roughly 10 kg of raw material for 1 kg of extract.
It describes the process, not the content. Two 10:1 extracts can contain very different amounts of active compounds, depending on the plant part, the solvent and the raw material itself.
Before accepting a ratio specification, ask three questions:
- Is the ratio native, or does the powder include carriers such as maltodextrin?
- Which solvent was used: water, ethanol or a mixture?
- Which plant part was extracted: root, leaf, fruit or fruiting body?
What a standardised extract tells you
A standardised extract guarantees a minimum content of a defined marker compound, for example 80% silymarin or 95% curcuminoids. This makes the amount per serving predictable from lot to lot, which is why most capsule and tablet formulas specify standardised grades.
Why the analytical method matters
The same material can give different figures depending on the method. UV spectrophotometry measures a broad group of compounds, while HPLC quantifies specific ones. That is why milk thistle extract is commonly offered both as 80% silymarin by UV and around 30% by HPLC. These figures do not necessarily describe different qualities.
Specification | What it guarantees | Typical use |
|---|---|---|
Ratio (e.g. 10:1) | How concentrated the extract is relative to the raw material | Labels that declare the dried-material equivalent |
Standardised by HPLC | Minimum content of individual marker compounds | Formulas where the marker per serving must be consistent |
Standardised by UV | Minimum content of a group of compounds | Groups such as polysaccharides or polyphenols |
How to compare two offers
- Compare like with like: the same marker, measured with the same method.
- Ask for a recent certificate of analysis for the exact lot, not a generic specification.
- Check the carrier and solvent declarations.
- Compare the price per gram of marker, not only the price per kilo.
A quick calculation helps: if your formula needs 475 mg of curcuminoids per serving, that is 500 mg of a 95% turmeric extract. You can test combinations like this in our formula calculator.
The cheapest kilo is not always the cheapest serving.