Trust tool
Proprietary blend decoder
A proprietary blend lists several ingredients under one combined weight without saying how much of each is inside, which lets a product name a fashionable ingredient while including only a token, ineffective amount. This tool explains the trick and flags when a blend is simply too small to contain an effective dose of its headline ingredient. Information only, not medical advice.
How the flag works
The logic is deliberately simple and conservative. If the entire blend weighs less than the effective dose of just one ingredient inside it, that ingredient cannot be present at an effective amount, because the rest of the blend must take some of the weight. So a 500 mg blend that names an ingredient needing 600 mg is flagged as very likely under-dosed. If the blend is larger than the effective dose, the tool cannot confirm the amount is right, because the dose is still hidden, so it tells you the number is undisclosed and to prefer a product that lists it.
Information only, not medical advice. This tool is educational and is not a substitute for a registered clinician. It does not diagnose anything and does not recommend that you take any supplement. Always read product labels and speak to your GP or pharmacist before starting, stopping or combining supplements.
Read more
Find effective doses on the ingredient evidence scorecard, price a product properly with the cost per effective dose calculators, and check you are not overpaying with are you overpaying for vitamins. More on the tools hub.
Frequently asked questions
What is a proprietary blend?
It is a group of ingredients listed under one combined weight, for example a "750 mg calm complex", without saying how much of each ingredient is inside. Ingredients are listed in descending order by weight, but the actual amount of each is hidden. That means a product can put a tiny, ineffective amount of the headline ingredient behind a larger filler and still name it on the label.
Why is hiding the doses a problem?
Because for most ingredients the evidence and any authorised health claim apply at a specific dose. If you cannot see how much of the active is in the blend, you cannot tell whether the product reaches that dose or just sprinkles a token amount, sometimes called fairy dusting. A clear label that states each ingredient amount lets you check; a blend total does not.
How does this tool flag the risk?
You enter the blend total and the dose the headline ingredient needs to be effective (you can find that on our ingredient evidence scorecard or a product that lists it). If the whole blend is smaller than the effective dose of just the headline ingredient, the product cannot possibly contain an effective amount once the other ingredients take their share, so we flag it as very likely under-dosed.
Are all blends bad?
Not automatically, but transparency is the tell. Reputable brands increasingly list every ingredient amount, even within a complex. A refusal to disclose doses is a reason for caution, not proof of a bad product. When in doubt, prefer a product that shows the numbers, and ask your pharmacist if you are unsure.
Editor, Her Vitals
Oliver leads Her Vitals's editorial coverage of women's life-stage health and supplements. He curates and reviews existing branded products across trying to conceive, pregnancy, postnatal, perimenopause, menopause and the senior years, weighing what the evidence supports against guidance from bodies such as EFSA, the NHS and NICE, and is clear that the content is information rather than medical advice.
Last reviewed: 13 June 2026