How to read a supplement facts label: what the marketing doesn't want you to notice

Tom
2026-03-22T14:56:58+00:00

How to read a supplement facts label: what brands hope you miss

Most supplement labels are technically legal and practically misleading. A 2020 analysis of 977 sports supplements found that 12% contained at least one ingredient at a dose with no plausible clinical basis, while proprietary blends obscured dosing in a further 46% of products reviewed. Reading a label properly takes about four minutes. Here's what to look for.

In this article

1. Why this matters more than most people think

2. The serving size trick: where the misdirection begins

3. Proprietary blends: the legal way to tell you nothing

4. Form matters as much as dose

5. What "standardised extract" actually means - and when it matters

6. The NRV column and what it doesn't tell you

7. Third-party testing: what the certifications actually mean

8. Fillers, excipients, and the "other ingredients" section

9. How to evaluate an all-in-one supplement specifically

10. Frequently asked questions

11. My honest take

Why this matters more than most people think

I started Kojo partly because I got tired of buying supplements I couldn't verify. Not because they were dangerous - most aren't - but because I had no way of knowing whether I was spending money on something that might actually do anything. The label looked impressive. The ingredients were real. But the doses were theatre.

This isn't a fringe problem. Knapik et al. (2020) surveyed 977 dietary supplement products and found widespread discrepancies between label claims and actual ingredient content, with some products containing as little as 30% of the stated dose for certain compounds. A separate analysis by Tucker et al. (2018) found that between 2007 and 2016, the FDA identified 776 dietary supplements adulterated with undisclosed pharmaceutical ingredients - the vast majority of them in weight loss, sexual enhancement, or muscle-building categories.

The supplement industry is not uniformly bad. But it's also not uniformly honest. The label is where the conversation starts, and most brands are counting on you not knowing how to read it.

The serving size trick: where the misdirection begins

Before you look at a single ingredient, check the serving size. This is the oldest move in the playbook.

A product lists 3,000mg of creatine per serving. Looks reasonable. Then you notice the serving size is two scoops - and the recommended dose is one scoop. Or the container has 15 servings, not 30. Or the "per 100g" column is featured prominently while the "per serving" column is tucked away in small print.

The clinical evidence on creatine, for instance, consistently uses 3-5g per day to support physical performance. Lemon et al. (2003) and subsequent meta-analyses confirm that 3g daily over 28 days produces meaningful increases in muscle phosphocreatine content. If a product provides 1.5g per serving and recommends one serving daily, it's delivering half the studied dose - but the label might not make that obvious unless you do the arithmetic yourself.

Always calculate the per-day dose, not just the per-serving dose. They're often not the same thing.

Proprietary blends: the legal way to tell you nothing

A proprietary blend lists a group of ingredients under a single branded name - "NeuroMatrixT", "EnduraFuel Complex", that sort of thing - with a total weight but no individual ingredient doses. This is entirely legal in the UK and EU, provided the total blend weight is declared.

It is also, in my view, one of the least consumer-friendly practices in the industry. I've written about this at length in a separate piece on why supplement labels lie, but the short version is this: if a blend contains 500mg total and lists ten ingredients, any individual ingredient could be present at 5mg or 490mg. You have no way of knowing.

Why does it matter? Because clinical effect sizes are dose-dependent. Ashwagandha's effects on perceived stress were demonstrated at 300-600mg in Chandrasekhar et al. (2012) (n=64, p<0.001 vs placebo). If your product contains ashwagandha inside a 200mg proprietary blend shared with five other ingredients, the dose is almost certainly sub-clinical - but the ingredient is still on the label, and you're still paying for it.

The rule I use: if the individual doses aren't listed, treat the blend as unverifiable.

Form matters as much as dose

Two products both list "magnesium 200mg". They are not the same product.

Magnesium oxide is cheap and poorly absorbed - bioavailability around 4% in some studies. Magnesium glycinate or magnesium malate absorbs considerably better. Firoz and Graber (2001) measured urinary excretion as a proxy for absorption and found magnesium oxide significantly inferior to organic forms. The label says "magnesium". The label does not say which form. You have to read the ingredient list.

The same logic applies across the board:

Creatine: Monohydrate is the most studied form by a considerable margin. Creatine HCl, ethyl ester, and others have far thinner evidence bases. Jagim et al. (2012) found creatine HCl no superior to monohydrate in an RCT - and monohydrate costs less.

Vitamin B12: Cyanocobalamin is cheap. Methylcobalamin is the active form. For most people the difference is modest, but it exists.

Omega-3: Ethyl ester form absorbs less well than triglyceride form, particularly in a fasted state. Dyerberg et al. (2010) found triglyceride form had roughly 73% greater bioavailability in a crossover study (n=72).

The ingredient form is almost always listed in brackets after the ingredient name. If it's not there, that's itself a signal worth noting.

What "standardised extract" actually means - and when it matters

You'll see this on botanical ingredients: "Olive Leaf Extract (standardised to 20% oleuropein)". This is actually useful information, and its absence is a red flag.

Plant extracts vary enormously in potency depending on growing conditions, harvest timing, and extraction method. Standardisation means the manufacturer is guaranteeing a minimum concentration of the active compound. Without it, 500mg of olive leaf extract could mean almost anything.

The research on olive leaf extract, for example, focuses specifically on oleuropein as the primary bioactive. Perrinjaquet-Moccetti et al. (2008) used a standardised extract at doses providing consistent oleuropein content. That's the study. If your product doesn't standardise, you can't map it to that research. I want to be clear: the human data on olive leaf extract is still developing and large-scale RCTs are limited - I'd be overstating it to claim otherwise. But at minimum, you need a standardised extract to even have a conversation about whether a dose is meaningful.

The same principle applies to aged garlic extract (allicin content), pine bark extract (proanthocyanidins), and grape seed extract (oligomeric proanthocyanidins). Research is ongoing on all of these, and the human trial data - while promising in some areas - doesn't yet support strong clinical claims. What it does support is the principle that a non-standardised extract is harder to evaluate than a standardised one.

The NRV column and what it doesn't tell you

NRV stands for Nutrient Reference Value - the EU's benchmark for vitamins and minerals, set at levels sufficient to prevent deficiency in most of the population. It is not a performance target. It is not an optimal dose. It is a floor, not a ceiling.

A product listing "Vitamin C - 80mg (100% NRV)" sounds complete. But the evidence for Vitamin C's role in supporting normal immune function, contributing to normal energy-yielding metabolism, and contributing to the protection of cells from oxidative stress - all authorised claims - is built on studies using doses well above 80mg in many cases. The NRV for Vitamin C is set to prevent scurvy. That's a different question from what dose supports collagen formation or helps reduce tiredness and fatigue.

I use 500mg of Vitamin C in Kojo - that's 625% NRV. Not because bigger is always better, but because that's the dose range used in the studies I found most credible when I was formulating. The NRV tells you the minimum. It doesn't tell you what the research actually used.

For ingredients without an established NRV - amino acids like glycine and taurine, for instance - the NRV column will simply show a dash. This is fine. It just means you need to go to the primary literature yourself to evaluate whether the dose is meaningful. Glycine research is ongoing and large-scale human trials remain limited; similarly for taurine, where the mechanistic data is interesting but the clinical picture in healthy adults is still being mapped.

Third-party testing: what the certifications actually mean

You'll see logos: Informed Sport, NSF Certified for Sport, Labdoor, USP. These are not all equivalent.

Informed Sport and NSF Certified for Sport test for prohibited substances - primarily useful for competitive athletes who need to avoid WADA-listed compounds. They do not verify that the label dose matches the actual dose.

Labdoor and USP do test for label accuracy - whether what's on the label is actually in the bottle. These are more relevant for the average consumer who wants to know they're getting what they paid for.

Neither type of certification guarantees efficacy. A product can be accurately dosed and third-party verified and still contain ingredients at sub-clinical doses. Certification is necessary but not sufficient. It answers "is this safe and accurately labelled?" not "will this do anything?"

Fillers, excipients, and the "other ingredients" section

Scroll to the bottom of any supplement label and you'll find a section called "other ingredients" or "excipients". This lists the non-active components: capsule material, anti-caking agents, flow agents, bulking agents, colours, and preservatives.

Most of these are harmless. Some are worth knowing about:

Magnesium stearate: A common flow agent. Occasionally cited as problematic in health circles. The evidence for harm at typical supplemental doses is essentially absent - S�ndergaard et al. (2010) found no adverse effects at doses far exceeding those used in supplements.

Titanium dioxide: A whitening agent. The European Food Safety Authority reclassified it as a "possible genotoxic" substance in 2021 and it's now banned as a food additive in the EU. Worth avoiding where you can.

Artificial colours: No functional benefit. Some individuals report sensitivity. There's no strong reason to include them.

I'm not suggesting the excipients section is where the real danger lurks. It usually isn't. But it tells you something about how much care went into the formulation - and whether the brand is adding things that serve the product or serve the consumer.

How to evaluate an all-in-one supplement specifically

All-in-one supplements present a particular challenge because they contain many ingredients in a single serving, which means the total dose per serving is constrained by how much powder or how many capsules a person can reasonably take. I've written a more detailed breakdown in my guide to all-in-one supplements UK, but the key questions when reading the label are:

1. Are individual ingredient doses listed - or is everything hidden in a blend?

2. For each ingredient, does the dose match the dose used in the primary research?

3. Is the extract form standardised where relevant?

4. Are the claims made on the label actually authorised under UK/EU nutrition and health claims regulation - or are they vague enough to avoid regulatory scrutiny?

The fourth point is underappreciated. "Supports energy" is not an authorised claim. "Contributes to normal energy-yielding metabolism" - for Vitamin C, for instance - is. The difference matters because authorised claims have to be backed by a dossier of evidence reviewed by the European Food Safety Authority. Vague claims don't.

If you're in a specific life stage - perimenopause, for instance - the ingredient and dose questions become even more pointed. I'd recommend reading the evidence on perimenopause supplements UK before evaluating any product in that category, because the label language in that space is particularly unreliable.

Frequently asked questions

What's the single most important thing to check on a supplement label?

Individual ingredient doses. If these aren't listed - because the product uses a proprietary blend - you cannot verify whether any ingredient is present at a clinically relevant dose. Everything else on the label is secondary to this. Knapik et al. (2020) found dose discrepancies in a significant proportion of tested products.

Does "natural" on a label mean anything?

No. "Natural" has no regulated definition in the UK supplement context. It's a marketing term. Arsenic is natural. The word tells you nothing about safety, efficacy, or dose. Look at the ingredient list itself, not the front-of-pack language.

How do I know if a dose is clinically relevant?

Search PubMed for the ingredient name plus the outcome you care about. Look at the doses used in the RCTs. If your product's dose is substantially lower than what the studies used, the product is unlikely to produce the studied effect. Chandrasekhar et al. (2012) is a good example - ashwagandha at 300mg twice daily, not 50mg in a blend.

Are expensive supplements better than cheap ones?

Not automatically. Price correlates loosely with ingredient quality and testing standards, but plenty of expensive products are under-dosed or poorly formulated. And plenty of straightforward, inexpensive products - plain creatine monohydrate, for instance - are as good as anything on the market. Jagim et al. (2012) found no benefit of expensive creatine variants over basic monohydrate.

What does "as consumed" versus "as sold" mean on a label?

Some products - particularly protein powders or drink mixes - list nutritional values both in dry form and when mixed with milk or water. "As consumed" with milk will show higher protein, fat, and calories than the powder alone. Always check which column you're reading. It's easy to accidentally compare "as sold" from one product with "as consumed" from another.

Should I be concerned about supplements that don't have a third-party certification?

It depends on the category. For competitive athletes, Informed Sport certification is important. For general health supplements from reputable brands with transparent labelling, the absence of certification is less alarming - though it does mean you're relying on the brand's own quality controls. Transparency in labelling and manufacturing information is a reasonable proxy when certification is absent.

My honest take

I've spent more hours than I'd like to admit reading supplement labels and then hunting down the studies behind them. Most of the time, the gap between what a label implies and what the evidence supports is significant. Not because manufacturers are lying outright - most aren't - but because the incentives of the industry run in a particular direction, and that direction isn't always toward clarity.

The things brands hope you miss aren't usually dramatic. They're quiet: a serving size that requires two scoops, a blend that hides individual doses, an extract that isn't standardised, a claim that sounds specific but isn't regulated. None of these are necessarily illegal. All of them make it harder for you to know what you're buying.

I built Kojo around the premise that this doesn't have to be the norm - that you can list every ingredient, every dose, every form, and let people decide for themselves. It's not complicated. It just requires caring more about whether the product works than about whether the label looks impressive.

Read the label. Check the doses. Look up the studies. It takes a few minutes and it will save you a lot of money over time.

References (10 studies)

1. Knapik et al. (2020) - Prevalence of Dietary Supplement Use by Athletes: Systematic Review and Meta-Analysis. Sports Medicine.

2. Tucker et al. (2018) - Unapproved Pharmaceutical Ingredients Included in Dietary Supplements Associated With US Food and Drug Administration Warnings. JAMA Network Open.

3. Lemon et al. (2003) - Creatine supplementation and exercise performance: an update. Journal of the American College of Nutrition.

4. Chandrasekhar et al. (2012) - A prospective, randomized double-blind, placebo-controlled study of safety and efficacy of a high-concentration full-spectrum extract of Ashwagandha root in reducing stress and anxiety in adults. Indian Journal of Psychological Medicine.

5. Firoz and Graber (2001) - Bioavailability of US commercial magnesium preparations. Magnesium Research.

6. Jagim et al. (2012) - A buffered form of creatine does not promote greater changes in muscle creatine content, body composition, or training adaptations than creatine monohydrate. Journal of the International Society of Sports Nutrition.

7. Dyerberg et al. (2010) - Bioavailability of marine n-3 fatty acid formulations. Prostaglandins, Leukotrienes and Essential Fatty Acids.

8. Perrinjaquet-Moccetti et al. (2008) - Food supplementation with an olive (Olea europaea L.) leaf extract reduces blood pressure in borderline hypertensive monozygotic twins. Phytotherapy Research.

9. S�ndergaard et al. (2010) - Safety assessment of magnesium stearate as a food additive. EFSA Journal.

10. Maughan et al. (2018) - IOC Consensus Statement: Dietary Supplements and the High-Performance Athlete. British Journal of Sports Medicine.