Five minutes with the Supplement Facts panel tells you more than any ad ever will.
Most people buying a supplement never actually read the label properly — they read the front of the bottle and the marketing copy. The Supplement Facts panel on the back is where the real information is, and it takes about five minutes to learn to read it properly, once you know exactly what the panel is legally required to show, and just as importantly, what it's allowed to leave out.
One thing up front, because it would be dishonest to write this article without it: Proco uses a proprietary blend in one of our own products. We're going to explain how to spot blends, why they limit what you can know, and then apply that same test to our own labels, publicly, including where we come out badly. Skip to "Now apply this to our labels" if that's what you're here for.
Step 1: Find the ingredient list — not the marketing claims
Flip the bottle over. You're looking for the "Supplement Facts" panel, which is required by the FDA to list every active ingredient and, in most cases, its exact amount. This is the only part of the label that's legally required to be accurate and specific — everything on the front is marketing.
The panel's format isn't a brand's choice — it's dictated by federal regulation. The same rule that requires the panel to exist, 21 CFR 101.36, also controls its layout, the order ingredients appear in, and when a percentage of Daily Value has to be shown next to an amount.1 That's useful to know because it means two products from completely different companies should be directly comparable, ingredient for ingredient, if both are following the same rule correctly — which is the exercise we've run publicly against Mind Lab Pro and Onnit Alpha Brain.
Step 2: Check for "proprietary blend"
If you see a bracketed group of ingredients followed by a single combined weight — "Proprietary Blend: 1,200mg" listing five or six ingredients underneath — that's a proprietary blend. It's legal: 21 CFR 101.36(c) explicitly permits it. A manufacturer using a proprietary blend must identify it as such, must state the blend's total weight (defined in the rule as "the total weight of all other dietary ingredients contained in the proprietary blend"), and must list every ingredient inside it in descending order of predominance by weight — but is not required to break out how much of that total weight belongs to any single ingredient.1
There's an important carve-out most explainers miss. The rule only lets a blend hide what it calls "other dietary ingredients" — herbs, amino acids, branded compounds. Vitamins and minerals with an established Daily Value are governed by paragraph (b)(2) and must still be declared individually with their own amounts, even when they sit in the same product as a blend.1 So if a label shows two vitamins with exact milligrams and then a 255mg blend containing eight other things, that isn't inconsistency or sloppiness — it's the regulation working exactly as written. It also tells you something: the ingredients the brand could hide, it did.
The problem is what that leaves hidden. Because ingredients are listed in descending order by weight, the first ingredient in the blend could be most of that total, and the ingredient you actually bought the product for could be a token amount at the bottom. There's no way to know from the label alone — the rule was written to protect a manufacturer's formula as a trade secret, not to help you dose accurately.
There is one piece of arithmetic a blend can't hide from you, and it's the most useful tool on this page: the total is a ceiling. If a blend is 255mg and contains eight ingredients, then no single ingredient can exceed 255mg, and the average is under 32mg. If the research on one of those ingredients used 200mg, you can conclude that either that one ingredient is nearly the entire blend and the other seven are trace, or nothing in there is at a studied dose. You can't tell which — but you can tell that a claim of "a clinically studied dose of all eight" is arithmetically impossible. Do that subtraction on every blend you're shown.
Step 3: Understand %DV — and when its absence is normal
Next to many ingredients you'll see a "% Daily Value" (%DV) column: a number showing what percentage of the government's established daily intake one serving provides. It's a simple ratio — the amount in the product divided by the Daily Value set for that nutrient. A supplement providing 30mcg of an ingredient with a 300mcg Daily Value shows 10% DV.2
What trips people up is that most specialty ingredients — herbal extracts, many amino acids, branded compounds — carry no %DV at all, and that's not a labeling shortcut or an oversight. The FDA has only established Daily Values (Reference Daily Intakes or Daily Reference Values) for a defined list of vitamins, minerals, and a handful of other nutrients. For everything outside that list, the regulation requires the label to place a symbol such as an asterisk in the %DV column, referring to a footnote reading "Daily Value not established."1 Proprietary blends get that same asterisk, for the same underlying reason: there's no government reference intake for a five-botanical blend, so no percentage can be calculated even in principle.
The practical upshot is worth internalizing: a missing %DV, by itself, is not a red flag — it's often just how the regulation works for that category of ingredient. A missing per-ingredient amount, buried inside a blend with nothing to check against any research at all, is the actual problem.
Step 4: Check the dose against the research
If a product isn't hiding behind a blend and gives you a specific per-ingredient dose, the next step is checking whether that dose is anywhere near what was actually used in the studies the brand is implicitly — or explicitly — referencing. A quick search of the ingredient name plus "dose study" usually surfaces the studied range. If a label lists an amount a fraction of what's typically studied, the ingredient is often there for the label, not the effect.
This is also where %DV can mislead you if you don't separate it from research dosing. A vitamin can sit at 100% DV and still be dosed well below what a specific clinical trial used to produce a specific outcome. %DV reflects a general nutritional-adequacy standard set for the whole population — it was never designed to tell you whether a dose matches what a study found necessary. Those are two different yardsticks, and a label can satisfy one while telling you nothing about the other.
A label can be fully compliant with FDA formatting rules and still tell you almost nothing about whether the dose actually works — compliance and effectiveness are answering two different questions.
Step 5: Watch for "complex" and "matrix" as blend synonyms
The regulation itself permits a blend to be identified by "other appropriately descriptive term or fanciful name" — which is why "complex," "matrix," "system," and "blend" are functionally interchangeable on a label.1 They're all ways of grouping ingredients under one combined weight instead of disclosing each one. If you see any of these terms attached to a specific weight covering multiple ingredients, treat it the same as a proprietary blend: the total is real, the individual split isn't disclosed, and the descending-order rule won't tell you how much of that order is a rounding error versus the bulk of the formula.
Step 6: Look at what's not there
Fillers, binders, and "other ingredients" are listed separately from the active panel and are usually inactive — cellulose, magnesium stearate, capsule shells — normal and not a red flag on their own. The capsule material is worth a glance if it matters to you, because gelatin and vegetable capsules both appear in the same product ranges; ours vary, and we've set out which is which in is Proco vegan and gluten-free. What's more worth noticing is when the active panel is short relative to the number of benefits claimed on the front of the bottle. A label promising energy, drive, recovery, and focus with three underdosed ingredients in a blend is making more promises than the ingredient panel can support. Beyond the panel, the next question is whether the contents match it at all, which is what a certificate of analysis and GMP certification speak to.
| What the panel shows | Compliant, fully-disclosed label | Red-flag label |
|---|---|---|
| Per-ingredient amount | Exact mg/mcg/IU listed for every active ingredient, on its own line | Ingredients buried inside a "blend," "complex," or "matrix" with only a combined total shown |
| % Daily Value | Shown where an RDI/DRV exists; asterisked "Daily Value not established" where it doesn't | Missing with no footnote, or the absence used implicitly to suggest potency instead of explained |
| Ingredient order | Descending order by weight, letting you judge rough proportion within any blend | Technically descending, but the combined weight still hides whether the ingredient you want is 5% or 50% of it |
| Blend total vs. ingredient count | No blend, so the question doesn't arise | Blend total divided by ingredient count lands far below any studied dose — yet the front claims all of them work |
| Claims vs. actives | Number of benefits claimed roughly matches the number and dosing of disclosed actives | Long list of benefits on the front, a handful of underdosed actives hidden in a blend on the back |
Now apply this to our labels
It would be easy to end the article here and let you assume Proco passes its own test everywhere. We don't, and running the checklist on ourselves is the only version of this article worth publishing.
Sleep Formula passes fully. Every active is declared individually with its own amount: valerian 150mg, chamomile 100mg, GABA 100mg, L-tryptophan 100mg, lemon balm 100mg, passion flower 100mg, melatonin 2mg. No blend, nothing to subtract, nothing to take on trust. You can check every one of those numbers against the research yourself — which is the whole point. The ingredient-by-ingredient version is in Inside Sleep Formula.
Cognitive Support does not pass. It has ten actives. Two — niacin (8mg NE) and vitamin B6 (5mg) — are declared individually, because as vitamins with established Daily Values the regulation requires it. The other eight — GABA, L-tyrosine, caffeine, bacopa, phosphatidylserine, alpha GPC, L-theanine and huperzine A — sit inside a 255mg proprietary blend, and the per-ingredient amounts are not disclosed. We have asked our manufacturer; those figures are not ours to publish. Apply the ceiling test from Step 2 to us and the arithmetic is unflattering: 255mg across eight ingredients averages under 32mg each, which is below the studied dose for several of them taken individually. So we will not tell you that any ingredient in that blend is at a clinically studied dose, because we can't know it and neither can you. It is also a gelatin capsule, not a vegetable one. If you want the per-ingredient discussion we can have, it's in Inside Cognitive Support, and the caffeine question specifically in how much caffeine is actually in Cognitive Support.
Sleep Support partly passes. Vitamin B6 (1.8mg), calcium (17mg), magnesium (13mg) and melatonin (10mg) are declared individually. A further 905mg sits in a 14-botanical blend with no per-ingredient breakdown — so the same ceiling arithmetic applies, across fourteen ingredients this time. It's a vegetable capsule. The honest version is in Inside Sleep Support: An Honest Breakdown.
Our two single-ingredient products pass by construction. Magnesium Glycinate declares 275mg elemental magnesium from 2,500mg magnesium glycinate across three capsules — note the source-ingredient-in-parentheses convention from 101.36(d), which is why you should always check whether a magnesium number is the elemental amount or the salt weight. Omega-3 declares 1,000mg fish oil providing 180mg EPA and 120mg DHA per softgel.
The five-minute checklist
Before buying: does the label give a specific dose for every ingredient, or is any of it hidden in a blend, complex, or matrix? If there's a blend, divide its total by the number of ingredients in it — does the average even reach a studied dose? Where a %DV is missing, is it explained by an asterisk and footnote, or just absent? Do the disclosed doses roughly match what you can find in the actual research for that ingredient? And does the number and dosing of active ingredients reasonably match the number of benefits being promised? If the answer to any of these is no, that's worth knowing before you buy — not after. Whether a blend is ever the right choice is a separate question, and we've argued both sides in single-ingredient supplements vs a blend.
References
- U.S. Food and Drug Administration / Electronic Code of Federal Regulations, "21 CFR 101.36 — Nutrition labeling of dietary supplements," particularly paragraphs (b)(2), (b)(3)(iv), (c) and (d). ecfr.gov.
- U.S. Food and Drug Administration, "Daily Value on the New Nutrition and Supplement Facts Labels," fda.gov.
Related reading: Why We Don't Sell "Brain Blends" (And What Actually Clears Our Bar) — which, read alongside the section above, is a narrower claim than its title suggests, and we'd rather you notice that than not.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Talk to your healthcare provider before starting any new supplement, especially if you take prescription medication or have a medical condition.