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What a standardisation is a percentage of
A standardisation percentage is the most reassuring number on a botanical label and the easiest one to misread. It tells you how concentrated an extract is. It does not tell you how much of it you are taking, and those are different questions with different answers.
A standardisation is a percentage of a weight. “95% curcuminoids” says that 95 per cent of the turmeric extract is the measured compound — and nothing at all about how much extract is in the capsule. Multiply it by a gram and you have 950 mg. Multiply it by the 1.9 mg ceiling this label permits and you have about 1.8 mg. Same percentage, different products.
The one standardisation on this bottle
The panel reads Turmeric (Curcuma longa) Rhizome Extract 95% Curcuminoids. Four pieces of information in one row: the common name, the species, the plant part, and the standardisation. It is the only standardisation anywhere on this label, and printing it is genuinely good practice — most labels in this trade print none at all.
It is worth pausing on that before the criticism, because the criticism is arithmetic rather than character. A manufacturer who prints 95% curcuminoids is telling you something specific and falsifiable about the raw material. A manufacturer who prints turmeric extract is telling you almost nothing, and could be using anything from a mild concentrate to something barely distinguishable from powdered spice.
The trouble is that the row sits inside a 575 mg proprietary blend which carries no individual amounts. So the label discloses the concentration of an ingredient whose weight it withholds — and a concentration without a weight cannot be turned into a dose by anybody.
What a standardisation actually says
A botanical extract is a mixture. You take plant material, pull compounds out of it with a solvent, remove the solvent and are left with a powder containing a great many things, one or two of which are what anybody has studied. Standardising means adjusting that process, or the finished powder, so that a stated fraction of it is the compound of interest.
So 95% curcuminoids is a statement about composition: in every hundred milligrams of this extract, ninety-five milligrams are curcuminoids. That is a high figure — turmeric rhizome as a culinary powder carries a low single-digit percentage — and it is the kind of figure that distinguishes a pharmaceutical-grade concentrate from a ground spice.
What it is not is a quantity. It is a ratio, and a ratio needs a second number before it means anything in a capsule. The second number is the weight of extract in the serving, and on a proprietary blend that is exactly the number that is missing.
The distinction in one line
Concentration tells you what the material is. Weight tells you what the dose is. A label can print either without the other, and only one of them is required.
The number a percentage needs
Percentages are persuasive because they look like measurements. They are not; they are instructions for a multiplication that the reader has to finish, and a label that supplies the percentage without the multiplicand has supplied half a fact.
This is not unique to botanicals. A Daily Value percentage has the same structure and gets away with it because the missing number is published: the FDA sets the Daily Value for magnesium at 420 mg, so 19% on this panel resolves to 80 mg and can be checked. Nothing equivalent exists for curcuminoids. There is no reference weight to divide into, so 95% resolves to nothing at all without the label’s help.
Which means the standardisation on this bottle is doing something slightly strange: it is the most technical-looking number on the panel, and it is the one that carries the least information about what you swallow.
One percentage, three weights
The same figure, applied to three different extract weights. Every row is honestly labelled 95% curcuminoids.
| Extract in the serving | Curcuminoids delivered | What it resembles |
|---|---|---|
| 1,000 mg | 950 mg | The upper end of the oral doses in the trials NCCIH summarises. |
| 500 mg | 475 mg | A typical trial dose. |
| 100 mg | 95 mg | Below the studied range, but still a measurable quantity. |
| 1.9 mg — the ceiling this label permits | about 1.8 mg | About five hundred times less than the lower trial dose above. |
Three of those four products could print exactly the same standardisation on the front of the box. The percentage does not distinguish them, and it was never designed to. Only the weight does, and on a proprietary blend the weight is the thing withheld.
The turmeric row, worked out
So what is the weight here? The label does not print it — but it prints enough for the weight to be bounded. Turmeric extract is fifth of six in the blend, and the magnesium row implies that about 567 of the blend’s 575 mg is magnesium glycinate, leaving roughly 8 mg for five ingredients. Applying the descending-order rule to that remainder caps the turmeric extract at about 1.9 mg. That derivation is the subject of its own post.
Now finish the multiplication the label started. Ninety-five per cent of 1.9 mg is about 1.8 mg of curcuminoids — a ceiling, not an amount, and the true figure could be lower.
The amber bar is a ceiling, not an amount. Turmeric extract is fifth of six in the blend, so once the magnesium glycinate is accounted for it cannot exceed about 1.9 mg, which at the printed 95% curcuminoids is about 1.8 mg of curcuminoids. The two reference bars are the range of oral doses in the curcumin trials NCCIH summarises. NCCIH’s own verdict on that whole literature is that “we don’t know enough to definitively conclude if turmeric or curcumin is beneficial for any health purposes” — so the comparison is not between a working dose and a small one. It is between a small one and a set of trials that did not settle the question.
What the research body says at any dose
It would be easy to end there, and it would be too neat. The comparison on that chart is not between a working dose and a small one, because there is no established working dose to compare against.
“We don't know enough to definitively conclude if turmeric or curcumin is beneficial for any health purposes.”
National Center for Complementary and Integrative Health — Turmeric: Usefulness and Safety
That is NCCIH’s summary of the whole oral turmeric and curcumin literature, at every dose anybody has used. So the honest reading of the chart is narrower and stranger than “too small to work”: it is a very small ceiling set beside a body of trials, run at hundreds of times the amount, that did not settle the question.
NCCIH adds two practical notes that bear on the same row. “Oral curcumin products vary in how much curcumin they actually contain” — which is precisely the problem a standardisation figure is meant to solve, and credit is due for printing one. And curcumin is poorly absorbed without something like piperine, which this formula does not include.
Standardisation is not extract ratio
One more confusion worth clearing, because the two numbers look alike and mean different things.
- A standardisation — 95% curcuminoids — describes the finished extract. It says what fraction of the powder in the capsule is the measured compound. It is the more useful of the two.
- An extract ratio — 10:1 — describes the manufacturing. It says ten parts of raw plant material went in for every one part of extract that came out. It tells you about concentration relative to the starting material and nothing about what is in the result.
Neither substitutes for the other, and neither substitutes for a weight. This label prints no extract ratio for either botanical, and no standardisation at all for the butcher’s broom — which, with no monograph at the bodies this desk reads and a ceiling of about 3.7 mg, leaves a row consisting of a name, a plant part and an upper bound.
Reading any standardisation
Read the percentage, and note what it is a percentage of
95% curcuminoids is a fraction of the extract, not of the capsule and not of the blend. Labels are rarely explicit about which, so assume the extract and check.
Find the weight of the extract
If it is printed, the job is a multiplication. If it sits inside a proprietary blend, it is not printed — go to the next step.
Bound the weight instead
Blend total divided by position gives a ceiling. If a nutrient with a Daily Value is declared from inside the blend, the ceiling gets much tighter.
Multiply out, and label the answer honestly
Percentage times ceiling gives a ceiling on the measured compound, never an amount. Here: 95% of at most 1.9 mg is at most about 1.8 mg.
Only now look up the studied range
In that order. Reading the label first anchors you to whatever it printed, and 95 per cent sounds generous until the weight it multiplies is on the page beside it.
The habit transfers to every botanical row on every panel. A standardisation is a genuine disclosure and deserves credit wherever it appears — but it is the second half of a sentence whose first half is a weight, and a reader who stops at the percentage has read the part the label wanted read.
On this product the finished sentence is: at most about 1.8 mg of curcuminoids, from an extract correctly identified by species, plant part and standardisation, inside a blend that is about 99% something else. Every clause of that came off the bottle.
Read the magnesium row before you decide
Thirty capsules, one a day. One amount is printed on this label — 80 mg of magnesium — and it is the amount that tells you what is left of the 575 mg blend for the other five ingredients. The live price and the 60-day return terms are both on the seller’s checkout screen.
60-day window · Questions first? The FAQ page answers most of them.