The descending-order trick
There is a way to read inside a proprietary blend without anyone telling you anything. It is one division, and it works on every US supplement label.
A US proprietary blend must list its ingredients in descending order of weight and publish the blend's total. From those two facts, the ingredient in position k cannot weigh more than the total divided by k.
That single division turns an undisclosed blend into a bounded one, and it is the only tool a buyer has against a label that will not publish amounts.
Why blends are hard to read
Before this post went live, Dr. James Bateman III, MD, MPH, a physician, checked it against the CogniMary label and the sources it cites. A proprietary blend is the most common way a supplement label avoids telling you what is in the bottle. It is entirely legal, it is used by companies of every size, and it leaves a buyer with a single number covering anything from three ingredients to twenty.
The usual advice at this point is to avoid blends. That is reasonable and not always practical: in some categories almost every product uses one. So it is worth knowing what can still be extracted from a label that has decided not to tell you.
The rule nobody quotes
21 CFR 101.36(c) is the regulation. It is usually quoted for what it permits — hiding the split — and almost never for what it requires.
It requires that the ingredients inside a blend be listed by name, indented beneath the blend line, in descending order of predominance by weight. Heaviest first. That ordering is not a convention or a courtesy; it is in the regulation.
Two facts, and that is all you need
The total weight of the blend, printed on the label.
The order of the ingredients, which the regulation guarantees.
The trick itself
Call the weights w₁ through wₙ, running heaviest to lightest, and call the total T.
Take any position k. Every one of the first k ingredients weighs at least as much as the kth, because the list is ordered. So the first k together weigh at least k × wk. And the first k together cannot weigh more than the whole blend.
Putting those together: k × wk ≤ T, and therefore wk ≤ T ÷ k.
The fifth ingredient in a blend cannot be more than a fifth of it. The tenth cannot be more than a tenth. No assumption, no estimate, no insider knowledge — just the label and the rule.
A worked example
The CogniMary label prints a 635 mg blend with eleven ingredients. Here is what the trick produces.
| Position | Ceiling | A researched dose at that position |
|---|---|---|
| 1 — cinnamon | 635.0 mg | 1,000 mg |
| 2 — ginkgo | 317.5 mg | 120–240 mg |
| 4 — bacopa | 158.8 mg | 300 mg |
| 6 — berberine | 105.8 mg | 1,500 mg |
| 8 — alpha lipoic acid | 79.4 mg | 600 mg |
| 11 — zeaxanthin | 57.7 mg | 2 mg |
Scroll this table sideways →
Ginkgo and zeaxanthin can be at their researched doses. The other four in that table cannot. The full chart runs all eleven.
What the trick cannot do
- It cannot tell you what is actually in the capsule. It is an upper bound.
- It cannot account for extract strength. A 50:1 extract at 60 mg is not the same as a powder at 60 mg, and most labels do not publish the ratio.
- It cannot rule out a combination effect. It can only tell you the product is not reproducing the individual trials.
- It gets weaker as the list gets shorter. On a three-ingredient blend the ceilings are generous and say little.
It is at its most powerful exactly where labels are at their least informative: long ingredient lists inside small totals, which is the house style of this entire category.
Using it in a shop
- Find the blend line and read the total.
- Count the names under it and note the position of the one you care about.
- Divide. That is the most it can be.
- Compare with the dose in the research. One search.
- If the ceiling is below the dose, the product cannot reproduce the study, whatever the front of the bottle says.
It takes under a minute once you have done it once, and it is the single most useful thing a supplement buyer can learn.
- U.S. Government Publishing Office21 CFR 101.36 — Nutrition labeling of dietary supplements — eCFR.gov · source
- Kongkeaw, Dilokthornsakul, Thanarangsarit et al. — 2014Meta-analysis of randomized controlled trials on cognitive effects of Bacopa monnieri extract — Journal of Ethnopharmacology · PMID 24252493 · source
- Snitz, O'Meara, Carlson et al. — 2009Ginkgo biloba for Preventing Cognitive Decline in Older Adults: A Randomized Trial — JAMA · PMID 20040554 · source
- Alzheimer's Drug Discovery FoundationBerberine — Cognitive Vitality For Researchers — alzdiscovery.org · source
- Chew, Clemons, Agrón et al. — 2015Effect of Omega-3 Fatty Acids, Lutein/Zeaxanthin, or Other Nutrient Supplementation on Cognitive Function: The AREDS2 Randomized Clinical Trial — JAMA · PMID 26305649 · source
Where the rule came from
The descending-order requirement is not an accident, and knowing why it exists makes it easier to trust.
Ingredient lists on food have been ordered by weight for decades, for the obvious reason: a consumer who cannot see amounts can at least see proportions. When the Dietary Supplement Health and Education Act created the Supplement Facts panel in the 1990s, the same logic was carried across.
The proprietary blend allowance was a concession to manufacturers who argued that full disclosure would let competitors copy a formula. The ordering requirement is what was kept from the consumer side of that bargain. It is the residue of a compromise, and it turns out to be worth more than either side probably expected.
It is worth noticing that no manufacturer is harmed by it. The order does not reveal a formula; it reveals a ranking. The ceiling technique is the buyer quietly extracting the last usable thing from a label designed not to be usable.
Three more things the order tells you
The ceiling is the headline use. There are three smaller ones worth knowing.
What the blend is mostly made of
The first ingredient is the heaviest. If it is the cheapest thing on the list — a common spice, a bulk powder — the blend total is flattering the formula.
Position one is the tell
Whether the marketing matches the formula
If the ingredient the advertising is built around sits ninth of eleven, the advertising is built around a trace. Compare the front of the bottle with the bottom of the list.
The oldest trick, visible
A floor as well as a ceiling
The last ingredient cannot be heavier than any other, so the blend total divided by the count is an upper bound on the lightest. On 635 mg over eleven names, nothing at the bottom exceeds 57.7 mg.
The other end
On CogniMary's label the first of those is the most interesting. Cinnamon — a kitchen spice with no cognition trial we could find — is the heaviest ingredient in a blend sold for memory and focus.
Doing it on a phone in a shop
The whole technique fits in one line of arithmetic, but the practical version has a couple of wrinkles worth knowing.
- Blends are sometimes stacked: a product can have two or three separate blends, each with its own total. Do each one separately.
- Ingredients listed outside the blend have real amounts. Read those first — they are the part of the label that is actually telling you something.
- Watch for an ingredient appearing both inside and outside a blend. It happens, and the quantified line is the only one you can trust.
- If a blend has three ingredients, the ceilings are generous and the technique says little. If it has fifteen, it says a great deal.
- A blend with no total at all is not compliant. That is worth walking away from.
None of this requires a calculator for most cases. Halves, thirds and quarters of a round number get you most of the way, and the cases that matter are usually the obvious ones.
What to do with the answer
Working out that an ingredient cannot reach its researched dose is only useful if it changes something.
- If the ingredient you wanted cannot reach its dose, buy that ingredient on its own. Most of the ones in this category are available singly, at published doses, cheaply.
- If several cannot, the formula is a list rather than a dose, and the ingredient count is doing the selling.
- If they all can, you have found an unusual product and the blend was probably unnecessary in the first place.
- If you still want it, that is a decision made with the arithmetic in front of you, which is the entire point of learning this.
The technique is not an argument against buying anything. It is an argument against buying something because of a number nobody published.
One sentence to remember
The whole technique
The kth ingredient in a proprietary blend cannot weigh more than the blend total divided by k.
Everything else on this page is elaboration.
If you take nothing else from this site, take that. It works on every US supplement label with a blend on it, it takes ten seconds, and it is the only tool a buyer has against a number that was published specifically so you could not check it.