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Proprietary Blends Explained: Why Amounts Matter
A proprietary blend lists a group of ingredients with one combined weight, and the FDA labeling rule lets the maker leave out the amount of each. Ingredients are listed by weight, so the first is the largest, but the split is unknown. That makes it impossible to match any single ingredient to a trial dose.
Written by the Prostadine label deskUpdated · 4 min read
The basics01
What a blend is
On a Supplement Facts panel, a blend is a named group of ingredients, often with a name such as complex or matrix, followed by a total weight and then the ingredients in descending order by weight. The individual amounts are not shown (21 CFR 101.36 (eCFR)).
Makers say a blend protects a formula from copying. Buyers experience it as a closed door. Both can be true, and the practical result is the same: you cannot see the dose.
The evidence02
What a blend does and does not tell you
| Item | What you can know |
|---|---|
| Total weight | Yes, the combined amount |
| Order of ingredients | Heaviest first |
| Each amount | No |
| Ceiling for any one ingredient | Total minus the others, so unknown but bounded (21 CFR 101.36 (eCFR)) |
| Match to a trial dose | Not possible unless the total is below the trial dose |
The numbers03
The ceiling is useful
A blend with a stated total gives you an upper limit. If a blend weighs 600 mg and has nine ingredients, no ingredient can exceed 600 mg, and the lower ones are likely far smaller than the first. If a trial used 320 mg of an extract and the whole blend is 300 mg, the product cannot match the trial.
This is simple arithmetic and a legitimate use of the label. It lets you ask, in a letter or a call, whether the product meets the dose the advert implies.
The catch04
Liquid and drop products
Drops and tinctures raise a twist: the label may give a serving size in millilitres but the weight of each ingredient in that serving may not be shown. The brand reviewed on this site gives a 2 mL daily serving in its materials and lists nine ingredients, but the images we hold show no Supplement Facts panel at all.
That is why this site refuses to quote any milligram figure for it. See our supplement facts page for what is and is not on view.
Safety05
Why it matters for safety
Amounts matter for risk as well as benefit. Iodine has an adult upper limit of 1,100 micrograms a day, and seaweeds vary from 16 to 2,984 micrograms per gram (NIH ODS, Iodine). A blend of several seaweeds plus iodine could add up quickly or barely register, and the label would not say which.
People with thyroid disease, or on thyroid medicine, need that number more than anyone.
What to do06
What to ask the maker
- What is the weight of each ingredient per serving?
- What extract ratio or standardisation is used?
- Can I see the certificate of analysis for my lot?
- Which human trial does the formula rely on, and at what dose?
- Who tests each batch, and for what?
A maker who is confident usually answers. A silence or a vague reply is an answer of its own.
On the label07
What a good label looks like
A transparent label lists each ingredient with its amount, the form used, such as an extract with a stated ratio, and the percentage of any marker compound. It names allergens and states a serving size and the number of servings. It allows you to compare it with a trial in a few minutes.
You can find the full rules in the FDA labeling regulation (21 CFR 101.36 (eCFR)), and a plain-language guide on our label guide.
In practice08
A fair verdict
Blends are legal. They are not wrong in themselves. They are a reason to lower your confidence in any claim about dose, and they raise the value of a certificate and a clear return policy.
FAQ09
Prostadine questions people ask
What does a proprietary blend line leave out?
A group of ingredients listed with a combined weight but without the amount of each.
Is a blend illegal?
No. The FDA labeling rule allows it, provided ingredients are listed in order of weight.
Can I work out the amount of each ingredient?
Only an upper limit, since none can exceed the total, and the first listed is the heaviest.
What if there is no Supplement Facts panel at all?
Ask the seller for it. Do not assume doses, and avoid relying on any claim that depends on them.
Who wrote this10
Written and reviewed by
Pages built from the bottle photos, the info page and linked NIH, FDA, NCI, FTC and peer-reviewed sources.
Last updated . Read our editorial standards and how we check reviews. This website is run by a licensed U.S. retail desk for Prostadine, not by the manufacturer. We earn money when you buy through our order links.
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