Proprietary blends on supplement labels: myths and facts

Imagine a recipe that lists flour, butter, sugar, vanilla and salt, then gives you the total weight of the cake but not how much of each ingredient went in. You'd know what's in it. You wouldn't know if it's a cake or a bowl of butter.

That's roughly what a proprietary blend does on a Supplement Facts label. It lists a group of ingredients under one name with a single total weight. Here are the most common beliefs about blends, and what's actually true.

Myth: "Proprietary" means a special, better formula

Fact: It's a labeling format, not a quality rating. A blend lets a company disclose the combined weight of several ingredients instead of each amount. The ingredients are listed from most to least by weight, but that's all the label has to say. The word "proprietary" tells you nothing about how well the product is made or whether it works.

Myth: If an ingredient is on the list, you're getting a useful dose

Fact: Not necessarily, and one analysis shows how common hidden doses are. Researchers reviewed the labels of the top 100 multi-ingredient pre-workout supplements. The products averaged 18.4 ingredients each, and 44.3% of all ingredients sat inside proprietary blends with undisclosed amounts. For beta-alanine, one of the most common ingredients, the average amount per serving was below the dose considered effective (Jagim et al., 2019).

That study looked at sports products, but the math applies to any blend. When research uses a specific dose, you need the amount per serving to know whether a product comes close.

Myth: More ingredients means more benefit

Fact: In a blend with a fixed total weight, every added ingredient takes a share of the same space. A long list can look impressive while each item is present in small amounts.

Here's a simple way to estimate. Because blend ingredients are listed in descending order by weight, the ingredient in position number n can't weigh more than the total divided by n. In a 500 mg blend with 10 ingredients, the fifth ingredient is at most 100 mg, and the tenth is at most 50 mg. Often it's far less.

Myth: With probiotics, the total CFU is what counts

Fact: Which strains you get, and how much of each, matters at least as much. A systematic review of 228 trials found strong evidence that probiotic effects are both strain-specific and specific to the condition studied (McFarland et al., 2018).

Dose can matter within a single strain, too. In a trial of 100 adults with digestive symptoms, Bifidobacterium lactis HN019 shortened whole gut transit time from 49 to 21 hours at 17.2 billion CFU a day, and from 60 to 41 hours at 1.8 billion CFU, while the placebo group didn't change (Waller et al., 2011). A label reading "probiotic blend, 20 billion CFU" across six strains can't tell you whether any one of them is present at an amount that was studied.

Myth: Blends are just a way to protect a secret recipe, so they're harmless

Fact: Protecting a formula is the usual explanation, and sometimes it may be the real one. But the result for you is the same either way. You can't compare the doses with research, you can't compare two products fairly, and you can't tell how much of a stimulant or a gut-irritating ingredient you're taking.

Myth: Any product with a blend should be avoided

Fact: Not always. A blend of flavorings or a minor herbal extra isn't a problem in itself. What matters is whether the ingredients the product is built around, the ones on the front of the bottle, come with their own amounts. For a probiotic or a fiber supplement, that's especially true, because the dose of the main ingredient is the whole point of the product.

How to handle a blend on the shelf

You don't need special tools for this, just the label and the calculator on your phone.

1. Find the ingredients the product is marketed for. Check whether each has its own amount.
2. If they're inside a blend, note the total weight and their position in the list.
3. Use the "total divided by position" rule to estimate the maximum possible amount.
4. Email the company and ask for the individual amounts. If they won't share them, that's an answer too.

As an example of the alternative, Daily Biotic lists each of its three strains with its own amount: L. plantarum 299v at 10 billion CFU, B. lactis HN019 at 10 billion CFU and L. acidophilus NCFM at 5 billion CFU.

Sources

1. Jagim AR, Harty PS, Camic CL. Common ingredient profiles of multi-ingredient pre-workout supplements. Nutrients. 2019;11(2):254. PMID 30678328
2. McFarland LV, Evans CT, Goldstein EJC. Strain-specificity and disease-specificity of probiotic efficacy: a systematic review and meta-analysis. Front Med (Lausanne). 2018;5:124. PMID 29868585
3. Waller PA, Gopal PK, Leyer GJ, et al. Dose-response effect of Bifidobacterium lactis HN019 on whole gut transit time and functional gastrointestinal symptoms in adults. Scand J Gastroenterol. 2011;46(9):1057-64. PMID 21663486

This article is for general information and isn't medical advice. Talk to your healthcare provider before starting a supplement, especially if you're pregnant, immunocompromised or take prescription medication.