After 20 years reviewing supplement formulations professionally, my eye goes to the same five places on every label. I don’t read them in full from top to bottom. I scan for the things that matter and form a judgment from those — because everything else on a supplement label is either secondary or irrelevant to whether the product is worth taking.
This article walks through each of the five checks in order. By the end, you’ll be able to evaluate any supplement label in under a minute. Not perfectly — that takes years. But well enough to avoid the most common and costly mistakes.
“Most of the decisions I make about a supplement happen in the first twenty seconds. The rest is detail. The five checks I’m about to describe are those twenty seconds.”
This is the single most important thing on any supplement label and the most commonly overlooked. The number of milligrams tells you the dose. The form tells you whether your body can actually use what you’re paying for.
Every mineral and many vitamins exist in multiple chemical forms with dramatically different bioavailability. Magnesium oxide and magnesium glycinate both say “magnesium” on the front label. One has roughly 4% bioavailability. The other, around 80%. That’s not a marginal difference — it’s the difference between a supplement that works and one that doesn’t.
The form appears in brackets after the ingredient name in the Supplement Facts panel. If there are no brackets — if it just says “Magnesium 200mg” without specifying the form — that’s a red flag. Quality manufacturers always disclose the form. It’s a competitive advantage when the form is good. When brands don’t disclose it, there’s usually a reason.
Every active ingredient should have its own dose listed in milligrams — clearly, individually, without ambiguity. This sounds obvious. In practice, a large proportion of supplements don’t do it.
Proprietary blends group multiple ingredients under a single total weight. You see the total — “Performance Blend 2,000mg” — but not what each ingredient inside that blend contributes. The manufacturer can put one ingredient at 1,900mg and another at 100mg, and you have no way of knowing. The label is not lying. It is designed to prevent you from finding out.
If I see a proprietary blend, I ask one question: is there a legitimate reason for this blend to exist that benefits the consumer rather than the manufacturer? In almost every case, the answer is no. I put it back.
Below the Supplement Facts table, most labels include an “Other Ingredients” section listing excipients — the non-active components added for manufacturing purposes. Fillers, flow agents, capsule materials, anti-caking agents. These aren’t the supplement itself, but they tell you about the manufacturing priorities of the brand.
A short, clean other ingredients section — rice flour, cellulose capsule, nothing else — is a quality signal. A long list of synthetic excipients doesn’t make a product dangerous, but it suggests a manufacturer who optimises for production efficiency rather than product quality.
Two specific things I watch for: magnesium stearate (a common flow agent that’s generally safe but overused) and titanium dioxide (a whitening agent banned in food in the EU since 2022 but still appearing in some supplements — a labelling and regulatory question worth noticing).
Many supplements contain an ingredient at a dose so low it couldn’t plausibly produce the effect claimed. This is a specific category of label manipulation that’s distinct from proprietary blends — here the dose is disclosed, it just isn’t enough to do anything.
This happens frequently with premium-sounding ingredients added to a formula to support marketing claims. A product marketed as “with ashwagandha” might contain 50mg of ashwagandha extract. Clinical studies on ashwagandha typically use 300–600mg. The ingredient is present. The dose is theatrical.
You don’t need to memorise effective doses for every ingredient — that’s what years of professional review develops. But for the supplements you take regularly, spending ten minutes checking what research uses versus what your product contains is always worthwhile. PubMed, Examine.com, and similar resources make this accessible.
The final check is the simplest and the most revealing: does what the back of the product says match what the front claims? This is where the advertising and the formulation are placed side by side, and inconsistencies become visible.
If the front says “powered by lion’s mane” — is lion’s mane on the back at a dose that could plausibly support cognitive function? If the front says “advanced magnesium formula” — does the back show a bioavailable form at a meaningful dose? If the front says “comprehensive vitamin support” — does the back show complete forms of the B vitamins rather than synthetic equivalents?
The front of a supplement package is advertising. It’s designed to create a feeling of quality and comprehensiveness. The back is information. When those two things tell the same story, you likely have a product that stands behind what it sells. When they diverge — as they frequently do — the back is always the truth.
Step 1 (10 sec): Flip to the back. Find the Supplement Facts panel. Ignore the front entirely.
Step 2 (15 sec): Check the form of every active ingredient. Brackets present? Good forms?
Step 3 (10 sec): Are all active ingredients listed with individual milligram doses? Or is there a proprietary blend hiding them?
Step 4 (10 sec): Scan the other ingredients. Long list of unrecognisables? Short and clean?
Step 5 (15 sec): Does the dose for each key ingredient match what you’d find in research? Does it back up what the front claims?
Want these five checks applied to your specific supplements?
The Label Review is exactly this — every ingredient in your stack assessed on these criteria, with a clear written report delivered within 72 hours. No call required. Starts at €49.
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