Guide
How to read a proprietary blend, worked on this label
A proprietary blend is one weight standing in for several ingredients, and it is legal. What it cannot withhold is the order: 21 CFR 101.36(c)(2) requires descending order of predominance by weight, so the ingredient at position n of an 430 mg blend cannot exceed 430 divided by n. On this panel no individual figure is printed inside the blend at all, so those plain divisions are the only bounds there are, they run from 430 mg at the top of the order to 47.8 mg at the foot, and every one of them is a maximum rather than a measurement.
By the Getrenew31 Editorial Desk · Last updated October 11, 2026
The method in four lines
Read time under a minute- A blend hides the weights, not the order. The law requires descending order of predominance by weight.
- So position n of an 430 mg blend is at most 430 divided by n. That runs from 430 mg at the top to 47.8 mg at the foot.
- This panel prints nothing inside the blend, so those plain divisions are the whole of what the label supports.
- A ceiling is never an amount, and the nine of them cannot be added together.
What a proprietary blend withholds, and what it cannot
A proprietary blend is one weight standing in for several ingredients. It is legal, it is common, and it is the largest thing a label can withhold while still being a complete label.
Printed on this panel
Proprietary Blend 430 mg, with nine names indented beneath it and a dagger against the total. Not one of the nine carries a figure.
What that line gives you is the sum. What it withholds is every individual weight. Nothing inside the 430 mg blend carries a figure, so the printed order is the only quantitative information there is.
What it cannot withhold is the order, and that one surviving fact is what the rest of this page is about. It works on any label that prints a blend.
The ordering rule, and the only bound it gives
One sentence of regulation turns a blend from a closed box into something a reader can do arithmetic on. Two more sentences say what the total means and why the division works.
21 CFR 101.36(c)(2), on how the ingredients in a blend must be listed
“shall be declared in descending order of predominance by weight, in a column or linear fashion” 21 CFR 101.36
The phrase that does the work is descending order of predominance by weight. Heaviest first, as a matter of regulation rather than house style. Without that one sentence nothing quantitative could be said about any name in a blend.
21 CFR 101.36(c)(3), on what the blend weight covers
“shall be the total weight of all other dietary ingredients contained in the proprietary blend” 21 CFR 101.36
So the printed total is the sum of every ingredient in the group: 430 mg here, covering nine. A reader who takes 430 mg as the amount of the first name has read a sum as a dose.
Why position nine is held to 47.8 mg
If the list runs heaviest first, the ingredient at position n cannot be heavier than the average of the n ingredients at or above it, because the n minus one above it are each at least as heavy. So its bound is 430 divided by n.
Read the first as a rule of thumb: if the list runs from heaviest to lightest and the whole blend weighs 430 mg, the ingredient in position n cannot weigh more than 430 divided by n. The reason is that the ingredients above it are each at least as heavy as it is, so n copies of its own weight would already exceed the total.
Its strength runs the wrong way round. At the top of the list it is almost useless: the first name is held to 430 mg, the blend total restated, which rules nothing out. It says most at the foot.
430 divided by the position, line by line
Here is the division done for every position on this label, with the division itself printed in the third column so the arithmetic can be checked rather than taken.
| Rank | Ingredient | The division | At most | Share of the blend |
|---|---|---|---|---|
| 01 | chicory root inulin | 430 ÷ 1 | 430 mg | 100% |
| 02 | babchi | 430 ÷ 2 | 215 mg | 50% |
| 03 | fennel seed | 430 ÷ 3 | 143.4 mg | 33% |
| 04 | fenugreek | 430 ÷ 4 | 107.5 mg | 25% |
| 05 | ginger root | 430 ÷ 5 | 86 mg | 20% |
| 06 | lemon balm leaf | 430 ÷ 6 | 71.7 mg | 17% |
| 07 | lion's mane | 430 ÷ 7 | 61.5 mg | 14% |
| 08 | slippery elm bark | 430 ÷ 8 | 53.8 mg | 13% |
| 09 | dandelion leaf | 430 ÷ 9 | 47.8 mg | 11% |
Two notes on the arithmetic. The rounding goes up, so position three is published as 143.4 mg rather than rounded down, because a bound rounded down would claim the label permits less than it does. The last column does not add to a hundred, and cannot: each figure is a separate worst case.
Every figure of that kind is a ceiling. It is the most the ingredient could possibly weigh, never the amount in the gummy, and the real weight could be very much smaller. The two the sales material leans on hardest make the point. Ginger root is at position 5 and lion's mane is at position 7, so they are held to 86 mg and 61.5 mg.
Renew31, from $49 a bottle. 30 gummies at 1 gummy a day, so a bottle is 30 days.
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- 30 gummies a bottle, 1 gummy a day
What would tighten a bound, and what does not
The bounds above are the naive ones. On another label they could be much tighter, and knowing what tightens them is the difference between using this method and reciting it.
- A printed amount inside the blend. One figure against one name caps everything below it at that figure and forces everything above it to be at least that heavy, which tightens every bound above the printed line too.
- A standardisation percentage. A marker compound given as a percentage of an extract turns a weight bound into a bound on a specific compound.
- A second declared total. Where a label splits a blend in two, each group bounds its own ingredients and the divisions get smaller.
None of those three is on this panel, so the table above is not a conservative reading of this label. It is the whole of what this label supports.
That cuts the other way too. A reader cannot conclude from these ceilings that any ingredient is present in a small amount. The first name could be nearly the whole blend or very little of it, and nothing printed decides which.
What a ceiling is worth once you compare it
A bound is only useful next to a figure somebody has published. On this label that comparison can be made once, and it is the sharpest thing the method produces here.
FDA’s 2018 review of non-digestible carbohydrates puts the studied intake for inulin-type fructans at “3 to 40 g/day” FDA a day. The first ingredient in this blend is chicory root inulin. The whole blend, all nine of it together, is 430 mg, which is 14 per cent of the lowest figure in that range: about 7th of it would fit into the smallest daily intake FDA reviewed. Inulin alone is some part of the blend and cannot be more than the whole of it.
Read that comparison carefully. The effect FDA recognised in that review is on bone mineral density and the absorption of calcium. It is not a gut finding, and no page on this site treats it as one. The finding FDA recorded there is this: “The strength of the evidence supports that inulin-type fructans extracted from chicory root or extracted inulin-type fructans from all sources, as well as synthetic inulin-type fructans, have a beneficial physiological effect on bone mineral density and absorption of calcium.” FDA
For the rest of the label there is nothing to compare a ceiling against. NCCIH publishes a finding for three of the declared things, fenugreek, ginger root and dandelion leaf, and no dose for any of them. And six of the ten are addressed by no federal source this desk opened at all. No published trial on the finished Renew31 formula was supplied with this stock and none appears in any source this desk opened. Every source cited here describes a single named ingredient, a category of products, or a labelling regulation.
The six this desk could find no federal source for
Bacillus coagulans, babchi, fennel seed, lemon balm leaf, lion's mane and slippery elm bark. Each was checked against the complete NCCIH index, the NIH ODS botanical list and FDA’s ingredient directory rather than searched for once and missed.
Four things this method cannot do
The method is worth having because its limits are as clear as its results. Here they are, so nobody has to find them out the hard way.
A ceiling is not an amount
It is the largest figure the arithmetic leaves open. The real weight can sit anywhere below it, and nothing printed on this panel narrows it further.
The ceilings cannot be added up
Each one assumes every ingredient above it is as light as the ordering rule allows. They are individually true and jointly impossible: bounds, not a breakdown.
Nothing here is standardised
No extract ratio, no marker compound and no standardisation percentage is printed for any of the nine botanicals. So a ceiling cannot be converted into an amount of any single active compound.
It says nothing about effect
The method bounds weights. Whether a bounded weight does anything is a separate question.
Run it on any panel that prints a blend. Find the total, count the positions, look for a figure inside the list, and divide. With nothing inside, as here, the plain divisions are where you stop. the ingredients page applies the same arithmetic one ingredient at a time.
Read the blend before the price
Three bottles is $69 each with free US shipping, which is 90 days of product against a 60-day window.
See the packs, from $49 a bottle
- 60-day money-back guarantee
- Free US shipping on 3 and 6 bottles
- 30 gummies a bottle, 1 gummy a day
Questions
Renew31: common questions
Is a proprietary blend legal?
Yes. 21 CFR 101.36(c) allows a group of dietary ingredients to be declared under one total weight with no individual amounts, provided they are listed in descending order of predominance by weight.
How do you work out a maximum for an ingredient in a blend?
Divide the blend total by the ingredient’s position in the printed list. If the order is descending, position n cannot exceed the total divided by n, because the ingredients above it are each at least as heavy. On a 430 mg blend that puts position four at 107.5 mg.
Does a ceiling tell me how much is in the product?
No. It is a maximum and never an amount. On this label no individual weight is printed anywhere inside the blend, so every one of the nine figures is a bound and the real weights are not published.
Can the nine ceilings be added together?
No, and adding them is the commonest mistake with this method. Each bound assumes everything above it is as light as the rule allows.
References
- Code of Federal Regulations, Title 21, Section 101.36. Nutrition labeling of dietary supplements. https://www.govinfo.gov/content/pkg/CFR-2024-title21-vol2/xml/CFR-2024-title21-vol2-sec101-36.xml
- U.S. Food and Drug Administration. Review of the Scientific Evidence on the Physiological Effects of Certain Non-Digestible Carbohydrates. June 2018. https://www.fda.gov/media/113659/download
Every source above was opened and read on October 11, 2026. None of them tested Renew31 itself. They describe single ingredients and the categories they sit in and the labelling regulations that govern this panel, which is a different thing from testing this finished formula.