A 10:1 ratio states how much plant went into an extract. It does not state how strong the extract is.
Extract ratios appear on specifications, in catalogues and on labels as two numbers and a colon: 4:1, 10:1, 20:1. They look like a measure of concentration, and they are often read as one. They are a statement about yield.
Here are six checks to make when a ratio is quoted to you, with the definitions regulators use and examples from our own catalogue and enquiry forms. Our earlier article covered the whole specification; this one stays with the ratio.
01 / THE DEFINITION
What do the two numbers count?
European medicines guidance defines the drug extract ratio (DER) as “the ratio between the quantity of herbal substance used in the manufacture of a herbal preparation and the quantity of herbal preparation obtained”: the number before the colon is the plant material, the number after it is the extract.1 A paper by authors from the United States Pharmacopeia gives the reading in plain terms: “a dry extract with an average native extract ratio of 10:1 means that approximately 10 g of dried raw material were required to produce 1 g of native/genuine extract”. It adds that the calculation should be made on the dried basis, whether the starting material was fresh or dried.3
Our catalogue uses the same form. Jasmine Extract is listed as a yellow-brown fine powder made from flower, with a catalogue specification of extract ratio 10:1.
Check: that the ratio is plant to extract, which plant part it starts from, and that it is calculated on dried material.
02 / THE YIELD
Why is a higher ratio not a stronger extract?
A ratio is the extraction yield turned upside down. If a tenth of the plant’s mass ends up in the extract, the ratio is 10:1; if a quarter does, it is 4:1. The same paper notes that for most dry botanical materials extracted with water or water-ethanol mixtures, the extractable matter is “usually between 10 and 25 percent”, which gives exactly those two ratios.3
So a ratio says as much about the plant as about the process. The paper’s own example compares two roots under one published standard: the first must contain at least 3.0% water-soluble extractives, which gives a theoretical native extract ratio of about 33:1; the second at least 27.0%, which gives about 4:1.3 Neither figure states the content of any compound. The authors call the belief that a higher ratio means a stronger, and therefore better, extract perhaps the most common misconception about these ratios.3
Check: what you need the ratio to tell you. If the answer is the level of a compound, ask for an assay as well.
03 / THE RANGE
Why is the ratio a range?
Plant material varies from lot to lot, and so does the yield. In the paper’s example, one 100 kg lot of starting material yields 14 kg of native extract and another yields 11 kg under the same conditions; the ratio is therefore 7–9:1. A single figure, it notes, generally stands as “a shorthand for the actual range”.3 European guidance asks for the ratio “given as the actual range”, and its own example of a valerian root dry extract is declared as 3–6:1.1
A range in a catalogue can mean something else: the span of grades that can be quoted. Black Maca Extract and Yellow Maca Extract are listed in our catalogue with reference extract ratios of 4:1–20:1. The ratio for an order is the one you specify in your enquiry.
Check: whether a range describes the batch-to-batch variation of one grade or the span of grades on offer, and which ratio your quotation refers to.
04 / NATIVE OR TOTAL
Does the ratio include the carrier?
European guidance distinguishes two ratios. The genuine, or native, DER relates the plant material to the extract without excipients; the total DER relates it to “the quantity of whole extract (with excipients) obtained”.2 The two can differ widely. In the paper’s example, 4 kg of starting material gives 1 kg of native extract, a ratio of 4:1; add 1 kg of carrier and the same material is 2 kg of finished powder at 2:1.3
Conventions differ, too. The European example declares the native ratio and states the excipients separately: 80% genuine extract, DER genuine 3–6:1, other excipients 20%.1 The paper quotes the American Herbal Products Association’s guidance for retail labelling, in which the second number represents “the amount of finished total extract”, carrier included.3 A ratio can only be compared with another ratio stated on the same basis.
Check: whether the ratio refers to the native extract or to the finished powder, and the percentage of native extract or of excipients.
05 / THE PROCESS
Which solvent, and was anything taken out?
Two extracts of the same plant at the same ratio can still differ in composition, because the solvent decides what is extracted. European guidance names “the production process, the extraction solvent, the genuine drug extract ratio” and the type of preparation together as the factors that essentially determine composition, and its declarations give the solvent next to the ratio: “Extraction solvent: Ethanol 70 % V/V”.1
A high ratio can also be the result of further processing. The paper describes one pharmacopoeial native extract with a ratio of about 8:1 and a purified extract made from it at about 25:1, “because about two thirds of the native extract is discarded during preparation”.3 The second is not three times the first; it is a different material. For suppliers and buyers, the authors conclude that it is necessary to disclose not only the ratio but “the complete botanical extract composition, including any excipients and their percentage in the extract, extraction solvents, and the amount of active or marker constituents”.3
Our enquiry forms leave room for this. The form for Valerian Root Extract asks for the valerenic acids target, the preferred extract ratio, and solvent or carrier requirements; the form for Oregano Leaf Extract asks for the preferred extract ratio and the preferred extract form or extraction method.
Check: the extraction solvent, and whether the material is a whole extract or a purified fraction of one.
06 / RATIO OR ASSAY
When do you need a ratio, an assay, or both?
European guidance sorts extracts into three types. Standardised extracts are “adjusted to a defined content of one or more constituents with known therapeutic activity”; quantified extracts are adjusted to active markers within a specified range; “other” extracts “are not adjusted to a particular content of constituents”.2 For that third type the declaration gives the ratio and the extraction solvent instead of a constituent content.1 The paper quotes the United States Pharmacopeia’s chapter on botanical extracts to the same effect: “Where active principles are unknown, the ratio of starting material to final product is stated.”3
In practice many specifications use both. Our product portfolio says so directly: specifications may use extract ratios or named active-compound levels. The enquiry form for Turmeric Extract asks for the total curcuminoids target, the preferred extract ratio, and dispersibility or carrier requirements.
Check: which your product needs: a ratio where the whole extract is what you are buying, an assay where a named compound matters, and both where your formula or label calls for both.
WHAT TO SEND
Ask for the ratio with its context
When a ratio is part of your specification, send:
- the ingredient, and the plant part if more than one is offered;
- the extract ratio you need, and whether you mean the native extract or the finished powder;
- any carrier, solubility or other technical requirements;
- the extraction solvent or method, if your product requires a particular one;
- a compound target and assay method, if you need one alongside the ratio;
- your estimated quantity and destination market;
- your name, company and contact details.
Customisation can include concentration, extract ratio, target active-compound levels, extraction options and carrier or solubility requirements. Specification ranges in our catalogue are references. Feasibility, availability and price are confirmed with your quotation. You can also request a sample for ingredient evaluation and tell us which technical documents you need, such as a specification sheet or Certificate of Analysis; our team confirms sample availability and the documentation available for the selected grade.
Product examples are taken from the YOHOLIFE® catalogue and enquiry forms; confirm the selected grade and its specification when enquiring. Sources 1 and 2 were written for medicines and are cited here for their definitions. The ratios and yields quoted from source 3 are that paper’s own examples, not specifications of our products.
