Every third immune supplement on the shelf carries a proprietary blend somewhere on its panel. The phrase is legal, common, and not inherently dishonest. It is, however, a legal mechanism that makes two very different kinds of formulas look identical on paper. That is worth understanding before you buy.
What the Law Requires and Does Not
Under the Dietary Supplement Health and Education Act of 1994 (DSHEA), a manufacturer listing a proprietary blend must disclose every ingredient within it and the total weight of the blend per serving. What it need not disclose is the individual amount of each ingredient. The FDA's labeling rules require only that ingredients inside a proprietary blend appear in descending order of predominance by weight.
The original rationale was intellectual property protection. If a manufacturer has spent years optimizing synergistic ratios across a multi-herb formula, publishing those numbers makes the formula trivially copyable. That logic holds for some formulas. The difficulty is that the same loophole can mask under-dosed or low-cost formulations.
The Legitimate Case for a Proprietary Structure
A proprietary label is not automatically a quality failure. Three conditions make the argument for one most credible.
First, standardization language. When a formula specifies an herb as standardized to 4% echinacosides or providing a defined percentage of alkylamides, the manufacturer makes a compound-level quality commitment regardless of the total blend weight. Research has flagged a real limitation here: a 2016 PMC analysis found that marker compounds used for herbal standardization do not reliably predict bioactivity when the chosen marker is not the pharmacologically active component of the plant. But a standardization statement is at minimum a verifiable commitment the manufacturer can be held to.
Second, third-party certification. A USP Verified, NSF Certified for Sport, or Informed Sport mark means an independent body has confirmed that what the label claims is present, at the stated amount, and free of specified contaminants. Certification does not tell you whether the dose is efficacious. It does tell you the label is not fabricated.
Third, formulation-level evidence. Some combinations of immunomodulatory herbs affect immune cell populations in ways that single ingredients studied in isolation do not. A 2022 systematic review published in PMC found that several botanical ingredients show promising immunomodulatory activity in human and animal studies, while noting that inconsistent standardization across commercial products makes direct efficacy comparison unreliable. When a manufacturer can point to formulation-specific data - not just individual-ingredient trials - the proprietary argument strengthens considerably.
When the Label Becomes a Screen
The evidence is clearer in the other direction when none of those conditions are met. A 2019 analysis of multi-ingredient pre-workout supplements found that 44.3% of ingredients were disclosed only as part of a proprietary blend with undisclosed individual amounts, and that average doses of several key actives fell below the thresholds studied in clinical trials. The mechanism requires no active deception on paper: a 500 mg proprietary blend listing four herbs can legally contain 450 mg of the least-expensive ingredient and divide the remaining 50 mg across the other three.
A 2023 peer-reviewed analysis of proprietary blend use in dietary supplements concluded that the practice precludes the ability of consumers and clinicians to evaluate dosing adequacy and recommended that manufacturers voluntarily disclose per-ingredient amounts where IP protection is not a genuine concern. Most manufacturers have not followed this recommendation.
On adulteration more broadly, a 2023 PMC review found that contamination with both undisclosed and absent claimed ingredients remains a live concern across the supplement category. Proprietary labels complicate third-party auditing because there is no per-ingredient benchmark to verify against.
A Practical Reading Guide
The label can tell you more than it first appears to. Here is what to extract from it.
- Total blend weight per serving. This number must appear on the label. Compare it against doses studied in published trials. If four herbs share a 350 mg blend and the evidence base for each suggests individual doses well above that, the arithmetic alone is informative.
- Order of predominance. Ingredients list heaviest first. If the active you are most interested in appears third or fourth in a four-ingredient blend, its share of the total is, at best, the fourth-largest fraction.
- Standardization statements. Language such as standardized to X% or providing Y mg of [named compound] is a verifiable commitment. The absence of such language removes one layer of accountability.
- Certification marks. NSF, USP, or Informed Sport on the label indicates that an independent body has confirmed the label claim is accurate and the product is free of specified contaminants. This does not confirm that individual doses are efficacious, but it does establish a quality floor.
- Certificate of Analysis availability. Manufacturers confident in their quality typically publish per-batch COAs or provide them on request. If no COA is available, that is worth noting before you buy.
For a closer look at what herbal immune labels are legally required to show - and what the supplement facts panel does not require - see What Herbal Immune Blend Labels Actually Tell You in the Journal.
What This Means for Immune-Focused Formulas
The botanicals most commonly appearing in immune blends - echinacea, elderberry, astragalus, andrographis - each have different active compounds that have been studied. The 2022 systematic review referenced above notes that while several of these botanicals show meaningful immunomodulatory activity in controlled studies, inconsistent standardization across commercial products makes it hard to compare how well products work. The point is not that blended formulas cannot work. It is that without knowing individual doses, a consumer cannot compare a given formula against the doses studied in the published evidence.
Questions worth asking any brand with a proprietary immune blend: Is this product third-party certified? Are standardization details available for each herb? Is there a published COA for the current production lot? A manufacturer that is confident in its formula typically has answers ready.
If you are weighing dosing strategies once you have selected a formula you trust, Two Modes of Herbal Immune Dosing and When to Switch addresses the practical timing question - whether to dose preventively across a season or reactively at the first sign of symptoms. The sourcing decision and the dosing decision are separate; both matter.
Arbudari and the Proprietary Herbal Question
Ayurnomics's Arbudari is formulated as a proprietary herbal complex in the immunity category. The label does not list individual ingredient weights, as is standard practice under DSHEA for proprietary formulations. The product is manufactured under FDA Good Manufacturing Practice (GMP) regulations, which govern identity, purity, strength, and composition of finished dietary supplements. Dose: per manufacturer directions, as the label does not list individual herbal weights within the proprietary formula.
Applying the reading guide above to Arbudari - or to any proprietary immune formula - makes sense and is encouraged. Ask for the COA. Look for standardization statements in the product documentation. Confirm third-party certification status. A formula that passes those checks is more trustworthy than a fully disclosed ingredient panel from a manufacturer with no independent quality verification in place. A formula that does not pass those checks should be avoided, regardless of what the front panel says.
The parallel sourcing question - how origin and extraction method determine the potency of a single-active immune product - is explored in Black Seed Oil Thymoquinone Levels Depend on Origin, which applies the same supply-chain analysis to a single compound rather than a blend.
If you are on prescription medication, pregnant, or breastfeeding, speak with your clinician before adding any herbal formula to your routine. Several herbal-drug interactions are known and may not appear on the label.
Browse the Immunity and Wellness collection to compare available formulations, review certification details, and request documentation before committing to a formula.
Want more like this? Join the Inner Circle for one considered piece every Sunday.