What is a proprietary blend, and why should you care?

Pick up any supplement bottle. Flip it over. Look at the Supplement Facts panel.

If you see individual ingredients with individual doses next to each of them, you're looking at a transparent label. You know exactly what you're getting and how much.

If you see a group name with a total weight, followed by a list of ingredients with no individual amounts, you're looking at a proprietary blend. And you have no idea how much of anything you're actually taking.

What a proprietary blend looks like

Here's an example. This isn't a real product, but it's based on labels we've seen dozens of times:

The vitamins at the top are individually dosed. You can check those against the research. But the "Performance Blend" is 800mg total across five ingredients. You don't know how much of each one you're getting.

Here's why that matters: a clinical dose of L-citrulline is 6,000-8,000mg. The entire blend is 800mg. Even if citrulline made up 100% of the blend (leaving zero milligrams for the other four ingredients), it would still be less than 14% of the dose used in studies.

What a transparent label looks like

Same category, different approach:

Every ingredient, every dose, individually listed. You can look up each one and check whether the amount matches what was used in clinical studies. No guessing.

Why brands use proprietary blends

The official reason is usually "to protect our formula from competitors." That sounds reasonable until you think about it for more than ten seconds. Creatine monohydrate is creatine monohydrate. Ashwagandha is ashwagandha. There's nothing proprietary about these ingredients. They're available from any raw materials supplier on earth.

The actual reason is cost. Here's how it works:

A brand wants to list ashwagandha on the label because it's a popular ingredient that helps sell the product. A clinical dose of KSM-66 ashwagandha is 600mg. But ashwagandha extract is expensive. Including it at 600mg per serving would significantly increase the cost of goods.

So instead, they include 50mg of ashwagandha (enough to legally list it), bury it in a proprietary blend, and let the consumer assume they're getting a full dose. The ingredient is on the label. The marketing can talk about ashwagandha. And nobody can prove it's underdosed because the individual amount isn't disclosed.

This is called "pixie dusting" or "fairy dusting" in the supplement industry. A trace amount of an expensive ingredient, included for marketing purposes rather than efficacy.

The descending order rule

FDA regulations require that ingredients within a proprietary blend be listed in descending order by weight. The first ingredient in the list is present in the largest amount. The last is present in the smallest.

This gives you some clues. If a blend lists "maltodextrin, creatine monohydrate, beta-alanine, caffeine" in that order, it tells you there's more maltodextrin (a cheap filler) than creatine. Not great.

But descending order only tells you the relative ranking, not the actual amounts. The first ingredient could be 790mg of the 800mg total, or it could be 200mg. You can't tell.

Are proprietary blends legal?

Yes. The FDA requires supplement labels to list all ingredients and the total weight of any proprietary blend, but it does not require disclosure of individual ingredient amounts within a blend. The regulation specifically allows this structure.

Legal doesn't mean good for you as a consumer. It just means the brand isn't breaking any rules by hiding the numbers.

How to read a supplement label

Here's what to check when you're evaluating a supplement:

1. Count the proprietary blends. Zero is best. If there are blends, how much of the total formula do they cover? A product with 30 individually dosed vitamins and one small blend is different from a product where 80% of the formula is hidden.

2. Check the maths. If a blend lists 12 ingredients with a total weight of 500mg, the average per ingredient is ~42mg. Most clinically studied compounds need 200mg or more to produce effects. The maths tells you most of them are underdosed.

3. Look up the clinical doses. For any ingredient you care about, search "[ingredient name] clinical dose" or "[ingredient name] study dose." Compare that to what's on the label. If the dose isn't listed (proprietary blend), that's your answer.

4. Check the forms. "Magnesium" can mean magnesium oxide (4% absorption) or magnesium bisglycinate (much higher absorption). "Vitamin B12" can mean cyanocobalamin (synthetic, needs conversion) or methylcobalamin (active form). The form matters as much as the dose.

5. Look for third-party testing. NSF Certified for Sport, Informed Sport, and USP are the gold standards. "Third-party tested" without naming the lab or certifier is a weaker claim. Published Certificates of Analysis are a good sign.

Real examples from our reviews

In our daily supplement comparison, we found proprietary blends across most of the market:

• AG1 individually doses its 34 vitamins and minerals, but hides ~42 superfood and phytonutrient ingredients behind proprietary blend totals.
• IM8 hides three key complexes: superfoods (4,100mg total), electrolytes (2,500mg total), and amino acids (1,580mg total). Their adaptogens and digestive enzymes complex is 200mg for the lot.
• Huel Daily Greens lists 91 ingredients in an 8.5g serving. The adaptogen complex is 171mg across 14 ingredients. A clinical dose of one of those ingredients (ashwagandha) is 225-500mg.
• Onnit Total Human has ten proprietary blends. Individual ingredient doses are hidden throughout.

The UK's Advertising Standards Authority banned Huel's marketing claims twice in two months (August and September 2024) for making health claims they couldn't substantiate. When you can't prove the doses are effective, the claims built on those doses fall apart.

In our creatine comparison, Nutricost refused to share their Certificates of Analysis publicly, calling it "proprietary information." Creatine is a single molecule. There's nothing proprietary about it.

Frequently asked questions