Walk down the "brain health" aisle of any supplement retailer and you'll see the same pattern: five or six ingredients, one undisclosed combined dose, and a label that says "proprietary blend." That phrase is doing a lot of work — it means the brand doesn't have to tell you how much of each ingredient is actually in the capsule, which means you have no way of knowing whether any of them are dosed at a level that's ever shown an effect in a human trial. It isn't a labeling quirk or an accident of formatting; it's a specific legal allowance, and most "nootropic stacks" on the market are built to take full advantage of it. That's the standard every new Proco product has to clear — and the one we're actively bringing two existing products in the range up to as well (see the correction near the end of this article). This isn't a complaint about any one brand — proprietary blends are the default format across the entire "nootropic" category, from mass-market drugstore stacks to premium direct-to-consumer brands charging far more per bottle.
The standard
New products are selected by category fit: does the ingredient serve cognitive function, sleep, or nervous-system and stress support. Safety and legality gate every ingredient, and every dose is disclosed and stated on the label. An ingredient with thinner or mixed human trial data can still earn a place if it fits the category and is safe at the dose used — we say so plainly on its own product or content page rather than pretending the evidence is stronger than it is. What the rest of this article is about — undisclosed "proprietary blends" that hide the dose of every ingredient inside them — is a separate, disqualifying problem on its own.
The loophole that makes brain blends possible
The reason proprietary blends dominate the nootropic category isn't an accident of formulation — it's written directly into the labeling rules. Under FDA regulation 21 CFR 101.36(c), a supplement using a proprietary blend only has to disclose the total combined weight of the blend and list its ingredients in descending order by amount. It does not have to disclose how much of any single ingredient is actually in the capsule. That one provision is why a bottle can list ten "brain-boosting" ingredients next to a total blend weight of, say, 800mg — while the ingredient at the bottom of that list, often the one with the strongest and most expensive clinical backing, could be present at a dose measured in single-digit milligrams. Nothing on the label tells you which.
The same paper spells out the practical consequence for anyone trying to check a blend's claims against the science: because the individual amounts aren't public, "the amount of a dietary ingredient in a proprietary blend is not available for calculating exposures in assessments of intakes or for determining doses in clinical trials." The authors note that researchers are left improvising — running chemical assays on finished products, extrapolating from similar formulas that do disclose amounts, or simply asking manufacturers, who have no obligation to answer. If trained researchers with lab access can't reliably determine what's actually in a blend, a customer reading a label in a store certainly can't.
This is why an undisclosed "proprietary blend" is disqualifying for any new product we launch. It's not that every ingredient inside a given blend is necessarily useless — some may well be dosed adequately. The problem is that there's no way to tell which ones are and which aren't from the label, and the incentive runs the wrong way: a filler amount of an expensive, well-studied ingredient looks identical on a label to a full clinical dose, so a brand has no financial reason to spend more per bottle than the format legally requires it to prove.
Not in the range yet — and why
Lion's Mane fits our category (cognitive function) and is a reopened candidate for the range — see the Product Roadmap — so evidence depth alone doesn't rule it out on principle; it isn't in the range yet because we haven't sourced and evaluated a specific product against our safety and dose-disclosure standard, not because the door is closed. The rest of the list stands for reasons beyond category fit: sourcing and quality-control problems, populations the evidence doesn't generalise to, or — for adaptogen blends — the fact that "adaptogen" isn't a real, evaluable ingredient in the first place.
- NMN / NR — human RCT depth is still thin, and much of the existing human data comes from small, short-duration trials.
- Shilajit — mostly traditional-medicine use; limited, low-quality human evidence, and quality control between shilajit sources varies widely.
- Lion's Mane — fits our category and is a reopened candidate, but human trial data is still limited and results vary meaningfully by extract; not in the range yet pending a specific product evaluation, not ruled out on category grounds.
- Reishi, Chaga and other mushroom blends — immune and cognitive claims aren't established in human RCTs at the doses sold, and combining several mushroom species together makes it even harder to attribute any observed effect to a specific one.
- Adaptogen blends generally — "adaptogen" isn't a recognised clinical category. It's a marketing term for a group, and each ingredient inside one has to be evaluated on its own. The blend label itself is a red flag, independent of what's in it.
- CoQ10 — some evidence in specific populations (statin users, older adults), not the general population.
A blend label is a red flag on its own — independent of what's actually inside the capsule.
What does clear it
Magnesium (specifically glycinate — form matters, generic magnesium oxide doesn't perform the same in absorption studies) and omega-3/EPA+DHA both have deep, repeated, independent human RCT support, and each is sold as a single ingredient at a disclosed, specific dose — never folded into a stack where the amount can't be checked. Creatine met the same bar and was part of the range on the same basis, but has since been discontinued from the Proco range. The current active range — Cognitive Support, Sleep Support, Sleep Formula, Omega-3, and Magnesium Glycinate — holds every ingredient to that same disclosed-dose standard, whether sold on its own or as part of a formulated blend. Where the trial literature specifies an effective dose range, our label matches that range, not the smallest amount that lets us print a familiar ingredient name on the front of the bottle. L-theanine is a good example of an ingredient that fits our category and has solid human evidence behind it but doesn't yet meet our dose-disclosure standard — it's already in two products in the range, inside a blend, and getting it an individually disclosed dose is part of the same correction covered below.
The point of publishing this
We'd rather you could check our homework than just trust our marketing. Every ingredient decision follows the same rule as every dose on our labels: if it doesn't serve cognitive function, sleep, or nervous-system and stress support, or if we can't put a specific, stated dose on the label, we don't put our name on it. Human trial depth still matters and we say so plainly when it's thin, but it's no longer the sole gate on whether something belongs in the range. We'd rather tell you exactly what the evidence does and doesn't show for an ingredient than dress up a blend label to look like something it isn't.
That's the standard we hold every new product to — and the one we're actively bringing Sleep Support and Cognitive Support up to.
Sleep Support and Cognitive Support each include a multi-ingredient blend without full individual-dose disclosure on the label — the exact format this article argues against. We're moving both formulas toward full individual-ingredient dosing, the standard Sleep Formula already meets for every ingredient it contains. Two of the ingredients in those blends — GABA and 5-HTP — get a closer look in the linked articles below, including the dose-disclosure and safety-guidance work in progress for each.
This article is for informational purposes only and has not been evaluated by the FDA. It is not intended to diagnose, treat, cure, or prevent any disease. Speak with a healthcare provider before starting any new supplement, especially if you take medication or have an existing health condition.
References
- Code of Federal Regulations, Title 21, Section 101.36 — Nutrition labeling of dietary supplements (proprietary blend declaration requirements). U.S. Food and Drug Administration / eCFR. ecfr.gov
- Perspectives on the Use of Proprietary Blends in Dietary Supplements. The Journal of Nutrition, 2023. pmc.ncbi.nlm.nih.gov
Where each ingredient actually lands: Ashwagandha and Cortisol: Why Extract Matters More Than the Herb, Bacopa Monnieri: The Evidence Is Real, But It Takes Weeks — Not Days, 5-HTP: Real Evidence, Real Risk — Why We're Cautious, GABA and the Blood-Brain Barrier: What Oral Supplements Can (and Can't) Do, L-Theanine: Real Evidence Behind a Hyped Ingredient, Rhodiola Rosea: Why the Evidence Is More Mixed Than It Looks (And Why It's Not in Our Range Yet) and Curcumin and Piperine: Why the '2000% Absorption' Claim Doesn't Hold Up.
Related reading: Is "Highly Sensitive Person" a Real Thing?