Guide
How to read a proprietary blend
The most useful thing this product teaches has nothing to do with this product. A proprietary blend hides every individual amount — and the same rules that permit it force a hard ceiling on every ingredient in it. Here is how to compute one, on any blend, in any shop.
The method in one line: divide the blend total by the ingredient’s position in the list. The FDA requires blend ingredients “in descending order of predominance by weight”, so if six items total 575 mg, the fourth cannot exceed 575 ÷ 4 = 143.8 mg. Where the blend also contains a nutrient with a Daily Value, a second and far sharper method applies.
The rule, in the FDA’s words
Nothing here is a trick or a loophole. The labelling rule itself supplies the arithmetic. Here is the paragraph, from the FDA’s Dietary Supplement Labeling Guide, reproduced without cuts.
FDA — Dietary Supplement Labeling Guide, Chapter IV
“You must identify proprietary blends by use of the term “Proprietary Blend” or an appropriately descriptive term or fanciful name. On the same line, you must list the total weight of all “other dietary ingredients” contained in the blend. Indented underneath the name of the blend, you must list the “other dietary ingredients” in the blend, either in a column or linear fashion, in descending order of predominance by weight. … Dietary ingredients having RDIs or DRVs must be listed separately and the individual weights declared.”
Four requirements sit in that paragraph. Name the blend. Print its total weight on the same line. List the constituents underneath in descending order of predominance by weight. And declare an individual weight for any ingredient that has an RDI or DRV — that is, a Daily Value — even when it sits inside the blend.
There is no requirement to print an individual weight for anything else. That is why a blend of six can carry one figure — and why complaining about the practice produces nothing, while reading it carefully produces numbers.
Why the order forces a ceiling
Descending order means the first-listed ingredient weighs at least as much as the second, the second at least as much as the third, and so on to the last. From that, plus the total, an upper bound follows for every position. The argument is short enough to check in your head.
The whole of the reasoning
Suppose the ingredient in position n weighed more than the total divided by n. Every ingredient above it weighs at least as much as it does, so those n ingredients together would weigh more than n times the total divided by n — that is, more than the whole blend. Impossible. Therefore the ingredient in position n cannot exceed the total divided by n.
That is the entire method. It needs no chemistry, no laboratory and nothing beyond the two things every compliant blend must print, and it works in a shop aisle or over the telephone.
It also has a useful shape. The bound on the first ingredient is the total itself, which tells you nothing; it tightens with every step down the list. In a blend, the interesting arithmetic is at the bottom.
The division, six times
Six divisions on the blend in front of us. The total is 575 mg and the positions run one to six, in the order the label prints them.
| Position | Ingredient, as printed | The division | Ceiling |
|---|---|---|---|
| 1 | Magnesium Glycinate | 575 ÷ 1 | 575 mg |
| 2 | Alpha Lipoic Acid | 575 ÷ 2 | 287.5 mg |
| 3 | Butcher’s Broom (Ruscus aculeatus) Root Extract | 575 ÷ 3 | 191.7 mg |
| 4 | L-Carnitine | 575 ÷ 4 | 143.8 mg |
| 5 | Turmeric (Curcuma longa) Rhizome Extract | 575 ÷ 5 | 115 mg |
| 6 | Coenzyme Q 10 (as Ubiquinone) | 575 ÷ 6 | 95.8 mg |
Six numbers, none printed on the bottle and all six forced by it. Two things are worth pausing on. The first row is no use — bounding the largest ingredient by the whole blend tells you nothing. And the six cannot all be attained at once: at their individual ceilings they would total 1,408 mg, nearly two and a half times the blend. Each bound is true separately; together they are far looser than reality.
That looseness is the honest weakness of the simple method. On most labels it is all you get. On this one it is not.
The sharper method: a nutrient inside the blend
Go back to the last clause of the FDA paragraph: “dietary ingredients having RDIs or DRVs must be listed separately and the individual weights declared”. A vitamin or a mineral inside a blend cannot hide in it. It has to appear on its own row, with its own weight.
That row is usually read as a courtesy to the shopper. It is worth far more than that whenever the nutrient is delivered as a compound rather than the bare element — a chelate, a salt, an oxide. The declared figure is the elemental weight; the ingredient in the blend is the whole compound, which weighs more. Divide one by the other and you have the compound’s weight, and therefore everything else’s.
The arithmetic is a schoolroom calculation done on a molecular formula. For magnesium glycinate, C₄H₈MgN₂O₄: 4×12.011 + 8×1.008 + 24.305 + 2×14.007 + 4×15.999 = 172.42, of which the magnesium atom is 24.305. That is 14.1% elemental magnesium by weight. Delivering the declared 80 mg therefore needs 80 ÷ 0.141 = about 567 mg of the compound.
The blend is 575 mg. About 8 mg remains for the other five combined, and applying the descending-order rule to that remainder collapses the ceilings from hundreds of milligrams to single digits.
The fraction is different for every compound, and it is always worth checking
The same sum on magnesium oxide, MgO, gives 24.305 ÷ (24.305 + 15.999) = about 60% elemental magnesium, so 80 mg of magnesium would need only about 133 mg of that compound. On trimagnesium dicitrate it is about 16%. The same declared 80 mg therefore implies a completely different remainder depending on which compound the label names — which is exactly why the form printed beside the nutrient is worth reading.
What the two methods give, side by side
| Ingredient | From the order alone | With the magnesium row | Factor |
|---|---|---|---|
| Alpha lipoic acid | 287.5 mg | at most 7.5 mg | about 38× tighter |
| Butcher’s broom root extract | 191.7 mg | at most 3.7 mg | about 52× |
| L-carnitine | 143.8 mg | at most 2.5 mg | about 58× |
| Turmeric rhizome extract | 115 mg | at most 1.9 mg | about 61× |
| Coenzyme Q10 | 95.8 mg | at most 1.5 mg | about 64× |
The last column is the value of one printed row. Without it, five ceilings sit in the range where a real dose could plausibly live and nothing can be concluded. With it, all five sit in a range where nothing published has ever been studied.
And there is an independent check. The descending-order rule puts magnesium glycinate first on this panel. If the arithmetic above were wrong — if the glycinate were a minor component — it would have to appear lower down the list. It does not. One chemical fact and one regulatory fact point the same way, which is the main reason to trust the result.
What a ceiling is not
This is where people who have just learned the method go wrong, and the error is made in both directions.
A ceiling is not an amount. “At most 1.9 mg” is a true statement about this label; “1.9 mg” is an invented one. The remainder could be alpha lipoic acid at 7 mg with the other four at a fraction of a milligram each, or five equal slices, and the printed label is identical.
A ceiling is not a typical value. There is no distribution here to be typical of. Nothing on the bottle distinguishes a coenzyme Q10 at 1.5 mg from one at a tenth of that.
And the asymmetry is total. The method gives an upper bound and never a lower one. You can show that an ingredient is not large; you can never show, from a blend alone, that it is not vanishing. That is what a proprietary blend costs a reader, and it is the reason this site prints ceilings and never converts one into a dose.
Doing it on any bottle
Find the blend line and read the total
It sits on the same line as the blend’s name and it has to be there. No total means the label is not compliant and the rest of this is moot.
Look for a separately declared nutrient
A row with a milligram figure and a Daily Value percentage. If it names a compound — and especially if it says the nutrient comes from the blend — you have the sharper method.
If you have one, do the elemental sum
Declared elemental weight divided by the compound’s elemental fraction gives the compound’s weight. Subtract from the blend total. What is left is what the rest of the blend has to share.
Count positions and divide
Total — or the remainder, if you got one — divided by position. That is the ceiling for that ingredient, in whatever units the total is printed in.
Set each ceiling against a published dose
The NIH Office of Dietary Supplements and NCCIH are where to look. If a ceiling already sits below the studied range, you have your answer without learning the amount.
Run it on this bottle: 575 mg across six ingredients, roughly 567 mg of it accounted for by the one row carrying a figure, leaving about 8 mg for five ingredients between them. Two printed numbers, one molecular weight and a division — more than the front of the box will ever tell you.
Checking a breakdown against the bounds
There is one more use for the ceilings, and it only arrives if a manufacturer ever publishes the figures. The bounds are how you audit them.
- Every declared figure must sit at or under its bound. A breakdown that puts the turmeric at 50 mg is not describing a blend whose magnesium row reads 80 mg elemental.
- The parts must sum to the printed total. Not approximately — a blend total is a declared weight.
- The order must match the panel. If the published figures put the fourth-listed ingredient above the second, one of the two documents is wrong.
- The nutrient row must reconcile. The compound’s weight, times its elemental fraction, has to return the declared elemental figure.
A breakdown failing any of those four tests is not a breakdown of the product in front of you. That is the practical reason to compute ceilings even when you expect to be given the real numbers later: they are the only independent check a reader has. The contact page sets out how to ask for them.
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.