Find the total and count the names
Both are printed. The total is on the blend line and the names are underneath it. Write down how many there are.
Proprietary Blends: What You Can Still Work Out
One total, several names, no individual amounts — and one division that nobody tells you about.
Quick answer
A proprietary blend declares several dietary ingredients under a single total weight instead of individually. 21 CFR 101.36(c) permits this: the total weight of the blend must be declared and the ingredients in it must be listed in descending order of predominance by weight. No individual amounts are required. Because the list is ordered by weight, the ingredient in position n cannot exceed the blend total divided by n — so a blend still yields an upper bound for every ingredient in it, though never a lower one.
What a proprietary blend actually is
It is a line on a Supplement Facts panel that reads something like Proprietary Blend — 400 mg — †, followed by a list of ingredient names with no numbers beside any of them.
That is not a loophole somebody found. It is written into the regulation. 21 CFR 101.36(c) sets out how dietary ingredients that are not declared individually must be presented: the total weight of the blend is declared, and the ingredients inside it are listed in descending order of predominance by weight. Nothing further is required.
Ingredients without an established Daily Value carry a symbol — usually a dagger — pointing at the statement Daily Value not established. You will see that on almost every blend line in the aisle.
So when a company uses a blend, it is not hiding anything unlawfully. It is exercising an option the rules give it, and the question worth asking is what that option costs you.
Why companies use them, and why buyers dislike them
The argument for. A formula is intellectual property. Publishing every amount lets a competitor copy the ratios exactly, and the ratios are frequently the only thing distinguishing one product from another in a category where the ingredients are all in the public domain. That is a real commercial concern and it is why the option exists.
The argument against. A blend also conceals how little of an expensive ingredient a formula contains. If a blend totals 400 mg and holds eight ingredients, one of them can be 393 mg of something cheap and the other seven a milligram each, and the label will be entirely truthful.
Both of those are true at the same time, on every blend, and the label never tells you which one applies. That is the actual problem: not that blends are dishonest, but that an honest blend and a cynical one look identical on the bottle.
There is a second cost, and it falls on people trying to be careful. A pharmacist checking an interaction needs an amount. A person comparing two products needs an amount. Somebody who has read the literature on a specific ingredient and wants a studied dose needs an amount. A blend removes the information from exactly the readers most likely to use it.
The phrase to watch for
Proprietary blend, matrix, complex, formula, proprietary formulation. Any of them followed by a single weight and a list of names is the same thing under a different word.
The one calculation a blend cannot prevent
It takes one division and it works on every blend on every shelf.
Descending order of predominance by weight is a formatting requirement, and it is also a mathematical constraint. Most people read it as the former. It is worth reading as the latter.
Here is the argument in full. Suppose a blend totals T milligrams and the ingredient in position n weighs more than T divided by n. Because the list is in descending order, every ingredient above it weighs at least as much. So those first n ingredients together weigh more than n times T/n, which is more than T — more than the whole blend. That is impossible.
Therefore: the ingredient in position n is at most T divided by n.
That single line is the entire method. The first ingredient can be the whole blend. The second can be at most half of it. The fifth at most a fifth. The tenth at most a tenth.
Then, if an ingredient carries a standardisation percentage, apply it. An extract that is seventh of seven in a 151 mg blend is at most 21.6 mg, and if it is standardised to 1% of an active compound, that compound is at most 216 micrograms. A standardisation inside a blend is worth more than it looks, because it converts a ceiling on powder into a ceiling on something the research is written about.
Worked example
A 400 mg blend with six ingredients. Position 1: at most 400 mg. Position 2: at most 200. Position 3: at most 133.3. Position 4: at most 100. Position 5: at most 80. Position 6: at most 66.7. If the ingredient you care about is fifth and the research used 300 mg, you already know the answer without any further information.
Ceilings by position, for three common blend sizes
Total divided by position. Every figure is an upper bound, and none of them is a dose.
| Position in the list | In a 150 mg blend | In a 400 mg blend | In a 1,000 mg blend |
|---|---|---|---|
| 1st | ≤ 150 mg | ≤ 400 mg | ≤ 1,000 mg |
| 2nd | ≤ 75 mg | ≤ 200 mg | ≤ 500 mg |
| 3rd | ≤ 50 mg | ≤ 133 mg | ≤ 333 mg |
| 4th | ≤ 37.5 mg | ≤ 100 mg | ≤ 250 mg |
| 5th | ≤ 30 mg | ≤ 80 mg | ≤ 200 mg |
| 6th | ≤ 25 mg | ≤ 67 mg | ≤ 167 mg |
| 7th | ≤ 21.4 mg | ≤ 57 mg | ≤ 143 mg |
| 8th | ≤ 18.75 mg | ≤ 50 mg | ≤ 125 mg |
About the product behind this blog
NeuroMind Pro is a liver supplement in 60-capsule bottles with no Supplement Facts panel in anything supplied to us. Six ingredients are named and not one carries an amount. We publish the gap rather than filling it.
Order NowRead the label firstWhat the method cannot do, and why that matters
It produces no floor. There is no arrangement of the rules that puts a lower bound on any ingredient inside a blend. The fifth ingredient in a 400 mg blend is at most 80 mg, and it could be 0.1 mg, and the label would be equally accurate either way.
This is the part that gets lost when ceilings are quoted. A ceiling is the kindest possible reading of a label — the most generous number consistent with what is printed. When a review says an ingredient is at most 30 mg against a studied dose of 300, the honest gloss is that the gap is at least tenfold.
It cannot separate a good blend from a bad one. A company that puts studied doses of everything inside a blend produces exactly the same label as one that puts a dusting of everything but the cheapest ingredient. The method cannot distinguish them, and neither can you.
It cannot answer a safety question. A pharmacist can tell you whether 200 micrograms of an enzyme inhibitor is a concern alongside your prescription. Nobody can tell you whether somewhere between a trace and 216 micrograms is. Where a blend contains an ingredient with a documented interaction list, the ceiling is the beginning of a conversation rather than the end of one.
A three-step habit for any blend
Divide by the position
Find the ingredient you are buying the product for, count where it sits in the list, and divide the total by that number. That is the most it can be.
Compare it with one study
One source, opened and read. If the ceiling is far below what the study used, no amount of front-panel language changes the arithmetic.
And it is reasonable to simply ask
Every argument on this page is about what a label permits. None of it stops a company answering a direct question.
If you are taking a prescription medicine and a blend contains an ingredient with a documented interaction, asking the seller for that one amount is a reasonable request with a clinical reason behind it. Some companies answer. Some publish a full panel on request. Some decline, which is itself information.
There is exactly one way to settle a dispute about a ceiling: print the amount. Any company that believes a review has understated what is in its product can end the argument in a single line of type, and the ones that do end it immediately.
About this guide
It is a general explainer about a labelling rule, written for readers rather than lawyers, and it makes no claim about any particular product. It is not legal advice and it is not medical advice. The regulation quoted is linked in full in our source list, and the arithmetic on this page can be checked against it in about five minutes.
Proprietary Blends: What You Can Still Work Out: common questions
What is a proprietary blend?
A way of declaring several ingredients under one total weight instead of individually. 21 CFR 101.36(c) allows it: the blend's total must be printed and the ingredients must be listed in descending order of predominance by weight, and that is all the regulation requires. Here it means one number, 151 mg, covering seven ingredients.
Why would a company use one?
The usual reasons given are protecting a formula from being copied and preventing competitors from reverse-engineering the ratios. The practical effect for a buyer is that you cannot compare any ingredient against the research, and you cannot compare this product against another one. We have no way to know which motive applies here, so we describe the effect rather than the intent.
Where do the ceilings on this site come from?
From the descending-order rule, and nothing else. If ingredients are listed heaviest first, the ingredient in position n cannot be more than the total divided by n — otherwise the ones above it would have to be smaller, which would break the order. So in a 151 mg blend the second ingredient is at most 75.5 mg, the fifth at most 30.2 mg, the seventh at most 21.6 mg. It is arithmetic, not an estimate.
So the ceilings tell you the doses?
No, and this matters. A ceiling is an upper bound. The descending-order rule sets no lower bound whatsoever. The bacopa could be 30.2 mg or it could be 0.5 mg; both are consistent with everything the label prints. Every figure on this site marked with a ≤ sign is the most that can be there, not the amount that is.
Is the blend legal?
Yes. The panel declares the total weight, lists the ingredients in descending order of predominance and carries the dagger pointing at “Daily Value not established”. That is what 21 CFR 101.36(c) asks for. Our criticism is not that the label breaks a rule; it is that the rule permits a label to tell you almost nothing.
How much huperzine A is in it?
At most 216 micrograms. The huperzia serrata extract is seventh of seven, so it cannot exceed 21.6 mg, and it is standardised to 1% huperzine A. Studies have used 50 to 200 mcg twice daily. That ceiling sits inside the studied range, which makes it the one number on this label a buyer most needs and the label does not print.
How much bacopa is in it?
At most 30.2 mg, and possibly far less. It is fifth of seven in a 151 mg blend. The systematic review we read covered six randomised trials at 300 to 450 mg of extract a day over twelve weeks — so the lowest studied dose is roughly twice the weight of the entire blend.
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Order NowRead the label firstNo price was published to us. We print no figure we have not seen ourselves. · 60-day guarantee from purchase · Not for under 18, pregnancy or nursing