The Hidden Dangers of Proprietary Blends: What You Don’t Know Can Hurt You

Key Takeaways

Proprietary blends on supplement labels don’t disclose ingredient amounts, leaving consumers in the dark.
Some blends contain high doses of stimulants like caffeine without warning, increasing the risk of heart problems.
The FDA doesn’t approve supplements before they’re sold—issues are usually addressed only after someone gets hurt.
Several products marketed as “natural” have been found to contain banned or prescription-only drugs.
Consumers must read labels carefully, avoid vague blends, and choose third-party tested supplements to stay safe.

Health Supplements

In the booming $40+ billion supplement industry, promises of peak performance, rapid fat loss, and boundless energy dominate product labels. Yet beneath the glossy marketing lies a murky truth: many supplements are engineered not for transparency, but for concealment. Central to this problem is the use of proprietary blends—undisclosed combinations of ingredients presented as trade secrets.

On the surface, these blends may appear scientifically sophisticated or proprietary in a positive sense. In reality, they often serve as legal shields for underdosed ingredients, hidden stimulants, or even banned pharmaceutical drugs. Most consumers don’t realize just how little is known about what they’re taking, or how little is required by law.

This article will break down the mechanics of proprietary blends, how they’re used to manipulate perception, what the FDA has found in them, the health consequences of ingesting mystery ingredients, and finally, how to protect yourself in a dangerously under-regulated market.

Understanding Labeling Loopholes: What the Law Does—and Doesn’t—Require

According to the FDA (2021), all dietary supplements must include a Supplement Facts panel listing ingredients and their total quantity per serving. But there’s a key loophole: when ingredients are grouped under a “proprietary blend,” the manufacturer is only required to disclose the total weight of the blend, not the individual amounts of each ingredient.

For example:

Proprietary Performance Matrix – 800 mg
• Beta-alanine
• Yohimbe Bark
• Caffeine Anhydrous
• Green Tea Extract

This label gives no way of knowing if you’re getting 700 mg of caffeine or just 50 mg. Either would be legal as long as the total equals 800 mg.

The loophole, according to Saldanha et al. (2023), was originally intended to protect intellectual property. But in practice, it enables companies to hide ineffective doses, overuse of cheap fillers, or excessive stimulant content, while maintaining a “science-backed” appearance.

To make things more confusing for consumers, even legitimate-sounding labels can mislead. Awais (2025) notes that ingredients must be listed in descending order by weight, but this still tells you nothing about how much of each you’re actually getting. Some brands rely on this ambiguity to include buzzwords like “green tea extract” or “L-citrulline” in trace amounts just to catch attention—what industry experts call “label dressing.”

In short, reading a supplement label doesn’t always mean understanding it. Without disclosed dosages, you’re left guessing what’s effective, what’s filler, and what could be harmful.

Why Manufacturers Use Proprietary Blends (And How You’re Misled)

Brands use proprietary blends for four main reasons:

To Underdose Expensive Ingredients

Effective doses of ingredients like beta-alanine, citrulline malate, or L-carnitine are expensive. Instead of including the clinically recommended amount, companies use trace quantities, then hide the shortfall inside a blend.

As Gordon (2020) notes, this allows manufacturers to list “popular” ingredients that consumers recognize, while keeping costs down.

To Overdose or Conceal Stimulants

Caffeine is cheap, widely effective, and addictive. It gives users a short-term boost, masking underperformance elsewhere in the formula. Because blend labeling doesn’t require specifying how much caffeine is present, users may unknowingly ingest 300–400+ mg per serving, especially when stacking products.

The Institute of Medicine (2014) found that hidden high-dose caffeine is linked to arrhythmias, seizures, insomnia, anxiety, and emergency room visits, particularly when taken in combination with other stimulants or medications. Caffeine also affects drug metabolism and can interact dangerously with antidepressants, blood pressure medication, and diuretics.

To Slip in Banned or Prescription-Only Drugs

Some of the most alarming FDA investigations into supplements have found hidden pharmaceutical agents inside proprietary blends. Because the formulas don’t specify individual amounts—or in some cases don’t list the drug at all—users were unknowingly ingesting prescription-only or banned substances.

For example, the FDA (2021) found dozens of weight-loss products claiming to be “natural” that actually contained sibutramine, a banned drug associated with increased risk of heart attack and stroke. In 2024, several tejocote root supplements were found to contain yellow oleander, a cardiac toxin (FDA, 2024a).

FDA Warnings, Recalls, and Enforcement Failures

While the FDA does issue warnings and product recalls, its power is limited by the supplement industry’s legal status. Unlike pharmaceutical drugs, supplements do not require pre-market approval. Companies can bring new products to market without proving they’re safe or effective, and proprietary blends make it harder for regulators to test or evaluate them.

Notable Examples:

Tejocote Root Adulteration (2024)
Nine out of ten weight-loss products labeled as containing tejocote root were instead adulterated with yellow oleander, a poisonous plant known for causing arrhythmias. These products were sold online and marketed as herbal weight-loss aids (FDA, 2024a).
Sibutramine in “Natural” Weight-Loss Pills
As early as 2008 and continuing through the 2020s, the FDA has flagged products containing sibutramine—a drug withdrawn from the market for cardiovascular risks—hidden within proprietary blends (FDA, 2021).
Top Health Manufacturing Warning (2024)
In June 2024, the FDA issued a warning letter to Top Health Manufacturing for failing to disclose blend weights and mislabeling supplement facts. This is a violation of 21 CFR §101.36, the regulation intended to enforce transparent labeling (FDA, 2024b).

But these enforcement actions are often reactive. As Bernstein and Bolte (2022) explain, the FDA typically acts only after adverse events occur or testing reveals a problem, not before. This leaves a gap where companies can operate unchecked until someone is harmed.

The Hidden Dangers of Caffeine in Proprietary Blends

Caffeine’s presence in proprietary blends is especially problematic:

It boosts perceived product effectiveness, masking underdosed actives
It can be harmful at doses above 300–400 mg, particularly in those with hypertension or heart conditions
It’s often combined with other stimulants like synephrine or yohimbine, multiplying risk
It doesn’t need to be quantified on the label if part of a blend

The Institute of Medicine (2014) reported that high caffeine intake, especially from dietary supplements, has been linked to arrhythmias, seizures, and even death. Young adults, athletes, and people on medication are particularly at risk when consuming multiple products that include undisclosed caffeine.

When the Label Doesn’t Tell the Whole Story

I had a patient who came in with persistent heart palpitations. She was otherwise healthy—normal EKG, normal labs, no cardiovascular history. After ruling out common causes, nothing explained her symptoms. It wasn’t until a follow-up visit that she mentioned using a health supplement. The label listed an “Energy Matrix” proprietary blend with no clear breakdown of ingredients. I advised her to stop it immediately. Within two days, the palpitations resolved completely. Cases like this highlight the clinical uncertainty physicians face when dosing information is hidden or omitted.

The problem is magnified when users “stack” pre-workouts, fat burners, and energy drinks—potentially exceeding safe limits without realizing it.

Real-World Risks: What Could Go Wrong?

When using a proprietary blend supplement, consumers face multiple overlapping risks:

You can’t confirm if the product works: Without individual doses, you can’t assess clinical efficacy.
You risk stimulant overdose: Especially if you’re using multiple supplements.
You can’t identify drug interactions: Caffeine and yohimbine, for example, interact with SSRIs and beta-blockers.
You may ingest hidden drugs: As with sibutramine or cardiac toxins found in prior FDA testing.
You can’t hold manufacturers accountable: They can change formulas without notice and remain legally compliant if they follow blend weight disclosure.

What You Can Do Now: Protecting Yourself in a Flawed System

While you can’t control how companies label their products, you can take the following steps to minimize your risk:

Read Beyond the Label

Avoid products that list “proprietary blends” without stating individual ingredient dosages. Look for full disclosure formulas where each active is quantified.

Research Therapeutic Doses

Use reputable sources like the NIH’s supplement database or PubMed to confirm whether ingredients are present in effective amounts. For example, beta-alanine requires ~3 grams daily—many blends provide <500 mg.

Be Cautious with Stimulants

If the label mentions “energy matrix,” “thermogenic,” or “focus blend,” suspect caffeine or yohimbe. Assume high doses unless proven otherwise—especially if you’re combining multiple supplements.

Choose Third-Party Certified Products

Look for certifications from:

NSF Certified for Sport
Informed Choice
USP Verified

These seals indicate the product was independently tested for label accuracy and contaminants.

Report Adverse Effects to the FDA

If a supplement makes you sick, or you suspect it caused harm, report it immediately via:

👉 FDA MedWatch: https://www.accessdata.fda.gov/scripts/medwatch/index.cfm?action=reporting.home

Your report could trigger a recall or investigation.

FAQs About Proprietary Blends, Supplement Safety, and Labeling Laws

What exactly is a proprietary blend on a supplement label?
It’s a group of ingredients listed under one combined weight, without revealing the individual amounts of each component.

Why do supplement companies hide ingredient dosages?
They claim it protects trade secrets, but it often hides low doses of expensive ingredients or high doses of cheap stimulants.

Are proprietary blends legal in the U.S.?
Yes. The FDA allows them as long as the total weight is disclosed and ingredients are listed in order of predominance.

Is this allowed in other countries?
Many countries, like Canada and EU members, require more transparency and have stricter pre-market regulations than the U.S.

Can I tell if a supplement contains too much caffeine?
Not if it’s part of a proprietary blend. The exact caffeine dose often isn’t listed.

What ingredients should I be cautious about in proprietary blends?
Caffeine, yohimbine, synephrine, green tea extract, and any ingredient labeled as part of an “energy,” “focus,” or “performance” blend.

Can proprietary blends include banned substances?
Yes. The FDA has found multiple blends spiked with illegal drugs, steroids, or unapproved pharmaceutical agents.

How do I know if a supplement is third-party tested?
Look for seals like NSF Certified for Sport, USP Verified, or Informed Choice on the label.

Why doesn’t the FDA regulate supplements like medications?
Because of a 1994 law (DSHEA) that limits FDA authority. Supplements don’t need pre-market approval.

Can companies change supplement formulas without telling consumers?
Yes. They can alter ingredients and still legally market the product under the same name.

Do all supplements use proprietary blends?
No. Some reputable brands list every ingredient with exact dosages—those are the safer options.

Are there any benefits to proprietary blends for consumers?
Very few. While they may occasionally represent a well-designed formula, most are used for marketing or cost-cutting.

What health risks are linked to undisclosed ingredient amounts?
Overstimulation, insomnia, heart palpitations, high blood pressure, anxiety, and even hospitalization in extreme cases.

Can proprietary blends cause drug interactions?
Absolutely. Without dosage info, your doctor can’t check for safe use alongside prescriptions.

Are “natural” supplements automatically safer?
No. “Natural” is unregulated and doesn’t guarantee purity, safety, or effectiveness.

How do I report a supplement that made me sick?
Use the FDA’s MedWatch system: Report a problem

What if the product doesn’t list a proprietary blend but still looks suspicious?
Even without blends, vague marketing, unverified health claims, or missing third-party seals are red flags.

Can I trust supplements sold on Amazon or TikTok shops?
Not always. Some have been flagged for mislabeling or adulteration. Stick to verified sellers with transparent labels.

Is it legal to sell a supplement that contains a banned drug?
No, but many products have slipped through until the FDA catches them in post-market testing.

Can caffeine or stimulants build up in your system?
Yes. Especially when combined from multiple sources or used daily, they can lead to dependency or chronic side effects.

Why does the label say “energy matrix” or “focus blend” instead of caffeine?
That’s marketing language often used to disguise stimulant content and make the product seem more “natural” or innovative.

What is “label dressing”?
It’s when brands include trendy ingredients in tiny, ineffective amounts just to put them on the label.

Can supplements interfere with lab results or medical testing?
Yes. Some can alter liver enzymes, blood pressure, or heart rhythms, confusing clinical assessments.

How common is supplement fraud?
More common than most people think. FDA investigations routinely uncover mislabeling, contamination, and undeclared drugs.

Do athletes need to be extra cautious?
Yes. Proprietary blends can contain banned substances that may cause failed drug tests even if the ingredient isn’t listed clearly.

Why don’t more people know about these risks?
Supplement marketing is aggressive, and regulation is weak. Plus, many adverse effects go unreported or misattributed.

Can children or teens safely use supplements with proprietary blends?
Generally not recommended, especially those with stimulants or weight-loss claims.

Are weight-loss and pre-workout supplements riskier than others?
Often yes—they’re more likely to contain stimulants, underdosed ingredients, or even banned substances.

What are signs a supplement may be unsafe?
Wild health claims, lack of third-party testing, proprietary blends, overly vague ingredients, or imported without traceability.

Can I bring a supplement to my doctor to check if it’s safe?
Yes, but if it uses a proprietary blend, even your doctor can’t assess safety without knowing the exact dosages.

What’s the difference between “proprietary blend” and “patented formula”?
“Proprietary blend” refers to undisclosed ingredient amounts; “patented” just means it has legal protection—neither guarantees effectiveness or safety.

Are any supplement companies transparent and trustworthy?
Yes. Some disclose full dosages, share clinical research, and use third-party testing. But they’re the minority.

Do expired supplements pose a danger?
They may be less effective or, in some cases, unsafe if degradation leads to chemical changes. Always check expiration dates.

Can supplements with proprietary blends be used long-term?
It’s risky. Without knowing the doses, long-term use increases the chance of cumulative side effects or interactions.

Why doesn’t Congress pass stronger supplement safety laws?
Industry lobbying is strong. The 1990s Mel Gibson vitamin ad campaign helped frame regulation as a threat to personal freedom, shaping public opinion and policy.

What’s the best way to shop for safe supplements?
Choose brands with full transparency, published dosing, clinical backing, and third-party certification. Avoid hype-heavy marketing or hidden blends.

Which types of supplements are most likely to be spiked with hidden drugs?
Weight-loss, erectile dysfunction (ED), and muscle-building supplements are the top three categories repeatedly flagged by the FDA for containing undeclared pharmaceutical agents.

Why are ED supplements especially risky?
Many “herbal” ED products have been found to contain sildenafil or similar compounds—the active ingredient in Viagra—without listing them. These can dangerously lower blood pressure, especially when combined with nitrates.

Are weight-loss supplements safe if they say ‘all-natural’?
Not necessarily. Products marketed as “natural” fat burners have been found to contain sibutramine (a banned drug), diuretics, and even heart toxins like yellow oleander.

What about testosterone boosters or “hardcore” pre-workouts?
These often contain aggressive stimulant blends or undeclared prohormones, which can affect hormones, liver function, and heart rhythm.

Do detox teas or colon cleanses contain hidden drugs?
Some do. While not as common, certain “slimming teas” and “cleanse” products have been found adulterated with diuretics or laxatives not disclosed on the label.

How can I spot a high-risk product?
Red flags include: dramatic promises (“lose 10 lbs in a week”), lack of ingredient dosages, imported products with broken English labels, or phrases like “not approved for children” or “use with caution.”

Are male enhancement pills sold at gas stations or online marketplaces safe?
Rarely. These are some of the most commonly adulterated supplements, often spiked with unlisted ED drugs and lacking any form of safety testing.

Is it legal to sell supplements with undeclared prescription drugs?
No, but many products remain on the market until the FDA receives a report or investigates. Enforcement is often reactive, not proactive.

What should I avoid if I’m looking for a safe weight-loss product?
Avoid anything that includes proprietary blends with stimulant-heavy ingredients or vague terms like “thermogenic matrix.” Stick to fully disclosed, third-party tested products.

Final Thoughts

The current regulatory structure for dietary supplements in the U.S. was shaped by the Dietary Supplement Health and Education Act (DSHEA) of 1994. This law significantly limited the FDA’s ability to oversee supplements before they reach consumers. Unlike pharmaceutical drugs, supplements do not require pre-market approval. Manufacturers are not obligated to prove safety, efficacy, or even accurate labeling prior to distribution.

This legal environment has allowed proprietary blends to thrive as a labeling strategy. While intended to protect intellectual property, in practice, they are often used to obscure ingredient dosages, reduce manufacturing costs, or exaggerate the presence of clinically studied compounds.

There is public awareness of these gaps, amplified historically by campaigns like the widely circulated 1990s advertisement featuring Mel Gibson being arrested for possessing vitamins. The ad, which was part of an industry lobbying push, portrayed regulation as a threat to personal freedom. The result was the preservation of a regulatory framework that remains largely unchanged, despite advances in supplement science and documented cases of consumer harm.

Today, this landscape continues to favor industry flexibility over consumer safety. With increasing political momentum to reduce federal oversight—especially under a second Trump administration—agencies like the FDA and NIH may face additional resource constraints. This could further weaken enforcement, making it more difficult to monitor mislabeled, adulterated, or unsafe supplements (Frank & Glied, 2025).

To be clear, not all manufacturers engage in deceptive practices. There are reputable companies that invest in clinical research, disclose full ingredient profiles, and submit products for third-party testing. However, in a system where transparency is optional, those companies are the exception rather than the standard.

Until regulatory reform occurs, consumers must remain cautious, informed, and proactive. Without structural changes, the burden of supplement safety will continue to rest on individuals, not institutions.

References

Bernstein, I. B. G., & Bolte, K. L. (2022). Is my patient taking an unsafe dietary supplement? AMA Journal of Ethics, 24(5), E390–E395. https://doi.org/10.1001/amajethics.2022.390

Gordon, R. (2020, March 13). Proprietary blends: Supplements with hidden risks. MedShadow. https://medshadow.org/supplements-proprietary-blends-hidden-risks/

Institute of Medicine. (2014). Caffeine in food and dietary supplements: Examining safety: Workshop summary. National Academies Press. https://www.ncbi.nlm.nih.gov/books/NBK202224/

Jagim, A. R., Harty, P. S., & Camic, C. L. (2019). Common ingredient profiles of multi-ingredient pre-workout supplements. Nutrients, 11(2), 254. https://doi.org/10.3390/nu11020254

Awais, Z. U. R. (2025, June 13). How to read a supplement label: What really matters? Vitauthority. https://vitauthority.com/blogs/healthyeah/how-to-read-a-supplement-label-what-really-matters

Saldanha, L. G., Dwyer, J. T., Hardy, C. J., & MacKay, D. J. (2023). Perspectives on the use of proprietary blends in dietary supplements. The Journal of Nutrition, 153(5), 1305–1308. https://doi.org/10.1016/j.tjnut.2023.03.035

U.S. Food and Drug Administration. (2021, August 18). Questions and answers about FDA’s initiative against contaminated weight loss products. https://www.fda.gov/drugs/frequently-asked-questions-popular-topics/questions-and-answers-about-fdas-initiative-against-contaminated-weight-loss-products

U.S. Food and Drug Administration. (2024a, January). FDA issues warning about certain supplements substituted with toxic yellow oleander. https://www.fda.gov/food/alerts-advisories-safety-information/fda-issues-warning-about-certain-supplements-substituted-toxic-yellow-oleander-january-2024

U.S. Food and Drug Administration. (2024b, June 3). Top Health Manufacturing, LLC: MARCS‑CMS 671665 — Warning letter. https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/top-health-manufacturing-llc-671665-06032024

Frank, R. G., & Glied, S. (2025, May 14). The Trump administration’s NIH and FDA cuts will negatively impact patients. Brookings. https://www.brookings.edu/articles/the-trump-administrations-nih-and-fda-cuts-will-negatively-impact-patients/