If you learn one thing about reading supplement labels, make it this. A proprietary blend lets a manufacturer list impressive ingredients without telling you how much of each is present — and the arithmetic usually reveals more than the marketing does.
US supplement labelling rules require manufacturers to list ingredients in descending order by weight, and to give amounts. A proprietary blend is the permitted exception: group several ingredients together, list them in descending order, and give a single total weight for the group rather than individual amounts.
So a label reading "Proprietary Blend 200 mg: maca, grape seed, guarana, green tea, Gymnema…" tells you the whole group weighs 200 mg and that there is more maca than grape seed. It does not tell you whether the Gymnema is 80 mg or 0.4 mg.
The stated reason is trade secret protection — stopping competitors copying a formula. That is a real consideration, and for a genuinely novel formulation it has some force.
The practical reasons are usually different:
This is the useful skill, and it takes thirty seconds.
Step one: find the blend total. Step two: count the ingredients in it. Step three: divide.
That gives you the average per ingredient — not the actual amounts, but a ceiling on the typical one. Then compare against research dosages for the two or three ingredients you actually care about.
A 200 mg blend containing twenty-two ingredients averages roughly 9 mg each. Gymnema is studied at 200–800 mg. Green tea extract at 300–500 mg. L-glutamine at several grams. Even if one ingredient took the entire blend, most would sit at the bottom of their range — and every other ingredient would then be at zero.
The test does not prove any specific ingredient is underdosed. It establishes whether the formula could possibly deliver research-comparable amounts of more than one or two things. Frequently it cannot.
Because dietary supplements are regulated differently from medicines. Under the framework established by the 1994 Dietary Supplement Health and Education Act, supplements do not require pre-market approval for safety or efficacy, and proprietary blend labelling is expressly permitted.
The FDA's own consumer guidance is worth reading if you want to understand what is and is not checked before a supplement reaches you. The short version: less than most people assume.
Email customer support with three questions:
Some companies answer all three. Some answer the caffeine question only. Some decline entirely. All three responses are informative, and it costs you one email before spending anything.
A proprietary blend is not automatically a red flag — some are dominated by one well-dosed active with supporting ingredients around it, which is a reasonable design. But it removes your ability to verify, and it shifts the burden onto the manufacturer's word.
Where a formula does disclose a key ingredient separately — as with chromium in some blood sugar products — that is worth noticing. It usually means the amount is defensible. The ingredients hidden inside the blend are the ones where the numbers would not survive scrutiny.
Our full analysis covers the proprietary blend, the hidden caffeine and who should skip it.
Read Our Review Check PriceDisclaimer: general information, not medical advice. Do not change prescribed medication based on anything here. If you take glucose-lowering medication, speak to your doctor or pharmacist before starting any supplement. See our full disclaimer.