The Short Answer
A proprietary blend is a legal mechanism that allows supplement manufacturers to list a group of ingredients with only the total combined weight, without disclosing how much of each individual ingredient is included. The FDA permits this under the Dietary Supplement Health and Education Act of 1994 (DSHEA), and it is one of the most consumer-hostile practices in the supplement industry. The label might say "Cognitive Support Blend 1,200 mg" and list eight ingredients, but you have no way of knowing whether the most expensive ingredient is dosed at 500 mg or 5 mg. In our scoring system, proprietary blends result in automatic downgrades on the transparency score.
How Proprietary Blends Actually Work
Under FDA labeling rules, supplement manufacturers must list all ingredients in descending order of predominance by weight within a proprietary blend. This means the first ingredient listed is present in the largest amount, and the last ingredient is present in the smallest amount. The total weight of the blend must be disclosed.
That sounds like enough information to make inferences. It is not, and here is why.
Consider a hypothetical "Testosterone Support Blend 1,500 mg" containing ashwagandha root extract, fenugreek extract, zinc, tribulus terrestris, boron, and bioperine. The clinically studied dose of ashwagandha (KSM-66) is 600 mg/day. The clinically studied dose of fenugreek extract is 500 mg/day. Just those two ingredients at clinical doses would take up 1,100 mg of the 1,500 mg blend, leaving 400 mg for the remaining four ingredients.
But the manufacturer is not required to dose either ingredient at clinical levels. Ashwagandha could be 700 mg (adequate) or 200 mg (useless). You cannot tell. The descending order rule tells you ashwagandha weighs more than fenugreek, but "more" could mean 400 mg vs 390 mg. The math does not constrain the possibilities enough to be useful.
Why Manufacturers Use Them
The industry offers two justifications for proprietary blends. One is legitimate but rarely applicable. The other is the real reason.
The stated reason: protecting trade secrets
The claim is that revealing exact ingredient amounts would allow competitors to copy a unique formulation. In pharmaceutical manufacturing, this argument has merit - specific ratios of active and inactive ingredients can represent genuine intellectual property developed through expensive R&D.
In the supplement industry, this argument is almost always hollow. The vast majority of supplement formulations use well-known ingredients at well-known doses derived from published clinical research. There is no secret to protect. The optimal dose of ashwagandha KSM-66 is published in peer-reviewed journals. A competitor does not need your label to know it is 600 mg/day. The "trade secret" defense is invoked to prevent consumers from seeing what they are getting, not to prevent competitors from copying innovation.
There are rare exceptions. Some nootropic stacks and pre-workout formulations involve genuinely novel ingredient ratios that have been developed through iterative testing. But even these products could disclose individual doses without competitive risk, since the competitive moat comes from branding, distribution, and customer loyalty - not from an ingredient ratio that any contract manufacturer could replicate.
The actual reason: cost reduction
This is the part the industry does not say out loud. Proprietary blends allow manufacturers to list expensive, marketable ingredients on the label while dosing them at a fraction of the clinically effective amount. The marketing department gets to put "ashwagandha, lion's mane, rhodiola" on the front of the bottle. The manufacturing department gets to use 50 mg of each instead of 600 mg, 500 mg, and 300 mg respectively. The consumer pays a premium price for a pixie-dust formula.
This practice is called "fairy dusting" or "pixie dusting" in the industry. Include a token amount of a trendy ingredient to put it on the label, then fill the remainder of the blend with a cheap bulk ingredient like maltodextrin or rice flour. Without individual dose disclosure, the consumer has no way to verify whether the product delivers what it implies.
The Math That Exposes the Problem
Here is a real-world scenario (composite example, not a specific brand). A "Premium Joint Support Blend" weighing 2,000 mg lists the following ingredients in order:
- Glucosamine sulfate
- Chondroitin sulfate
- MSM
- Turmeric extract (95% curcuminoids)
- Boswellia serrata extract
- Hyaluronic acid
- BioPerine (black pepper extract)
The clinically effective daily doses from published research:
- Glucosamine sulfate: 1,500 mg
- Chondroitin sulfate: 800-1,200 mg
- MSM: 1,500-3,000 mg
- Turmeric extract: 500-1,000 mg
- Boswellia serrata: 300-500 mg
- Hyaluronic acid: 80-200 mg
- BioPerine: 5-10 mg
Clinical doses for just the first three ingredients total 3,800-5,700 mg minimum. The entire blend is 2,000 mg. It is mathematically impossible for this product to contain clinical doses of even the top three ingredients, let alone all seven. The label looks impressive. The product cannot deliver what the label implies.
This is not a marginal issue. It is systematic, and it exists specifically because the blend structure prevents consumers from seeing the math.
How This Affects Our Scoring
On our scoring methodology, proprietary blends directly impact the transparency score:
- Products with full ingredient disclosure and no proprietary blends are eligible for an A in transparency
- Products using proprietary blends where key ingredients can be inferred as adequately dosed (based on blend weight and ingredient count) may receive a C
- Products using proprietary blends that mathematically cannot contain clinical doses of featured ingredients receive a D or F in transparency
Since transparency is 25% of the overall score, a proprietary blend automatically caps a product's ceiling. A product that might otherwise score an A on evidence, quality, and value will top out at a B or B+ overall if it hides behind a blend. This is intentional. If you will not tell the consumer what is in the product, the product does not earn full marks.
Brands That Get It Right
The good news: the market is shifting. Consumer awareness of proprietary blend issues has grown significantly, and many of the highest-rated brands on our site have moved to full disclosure as a competitive advantage.
- Transparent Labs made full disclosure their founding principle. Every ingredient with the exact milligram amount on the label. No exceptions.
- Legion Athletics publishes the specific clinical studies that inform each product's dosing and discloses all ingredient amounts.
- Thorne uses full disclosure across their product line. As a practitioner-grade brand, ingredient transparency is expected by their core customer base.
- Pure Encapsulations discloses all ingredient amounts. Their hypoallergenic positioning requires ingredient specificity.
- Momentous discloses all ingredient amounts alongside their NSF Certified for Sport testing.
The trend is clear: brands competing on quality and trust are abandoning proprietary blends because transparency is a selling point. The brands still using them are, increasingly, the ones that have something to hide.
How to Protect Yourself
- Check for the words "Proprietary Blend" on the Supplement Facts panel. If you see them, every ingredient listed under that header has an undisclosed individual dose.
- Do the math. Add up the clinical doses of the ingredients listed. If the sum exceeds the total blend weight, the product is underdosed on at least some ingredients. If the sum significantly exceeds the blend weight, the product is likely underdosed on most or all of them.
- Look up the clinical dose. For any ingredient you care about, search for the clinically studied dose. Our supplement scorecards list the clinical dose for every ingredient we cover. If the product does not disclose the amount, you cannot verify it meets the threshold.
- Prefer products with full disclosure. There is no shortage of supplements that tell you exactly what you are getting. There is no reason to buy one that does not.
- Ignore "clinical dose" marketing claims on blend products. Some companies claim their blend delivers "clinical doses" while still hiding individual amounts. Without verification, this claim is unverifiable and should be treated skeptically.
The Regulatory Gap
The FDA could close this gap by requiring individual ingredient disclosure on all supplement labels. The technology and precedent exist - prescription drugs must disclose exact amounts of all active ingredients. The Dietary Supplement Health and Education Act of 1994 created the loophole, and despite repeated calls for reform from consumer advocacy groups, the proprietary blend exemption remains in place.
Until the regulatory environment changes, the market is the enforcement mechanism. Brands that embrace transparency are rewarded with trust and repeat customers. Brands that hide behind blends increasingly lose market share to competitors willing to show their work. Our scoring system is designed to accelerate this trend.
FAQ
Are all proprietary blends bad?
Not all, but the majority are. A product with a two-ingredient blend (say, magnesium glycinate and magnesium taurate totaling 400 mg) is much less concerning than a seven-ingredient nootropic blend totaling 1,000 mg. The fewer ingredients in the blend and the higher the total weight relative to clinical doses, the less room there is for pixie dusting. But even in the best case, full disclosure is always preferable.
Why do some popular brands still use proprietary blends?
Brand inertia and margin protection. Reformulating to clinical doses would increase manufacturing costs. For products with large existing customer bases (particularly in the pre-workout and testosterone booster categories), the marketing machine drives sales regardless of formulation quality. As long as consumers keep buying, there is no financial incentive to change.
Does "clinically dosed" on the label mean anything?
Not unless the individual ingredient amounts are disclosed. Any company can put "clinically dosed" on a proprietary blend product. Without seeing the actual numbers, you cannot verify the claim. Treat it as marketing copy until proven otherwise with visible dosing data.
Do proprietary blends affect safety?
Potentially. If you do not know how much of each ingredient you are taking, you cannot assess drug interactions or cumulative exposure from multiple supplements. This is particularly relevant for ingredients with meaningful upper limits or drug interactions (such as St. John's Wort, which can interfere with birth control and antidepressants). Knowing the dose is not just about efficacy - it is about informed consent.
These statements have not been evaluated by the FDA. Dietary supplements are not intended to diagnose, treat, cure, or prevent any disease.