Turn over almost any bottle of vitamins and you’ll find a health claim printed in confident type: “supports immunity,” “boosts energy,” “detoxifies the body.” Some of that wording is legally backed. Some of it isn’t allowed at all. The difference matters, because in the UK, health claims on supplement labels aren’t a matter of marketing taste — they’re governed by law, and there’s an official register that decides which wording a manufacturer is permitted to use.
The rule: only claims on the register are legal
Since the UK left the EU, health claims on food supplements sold in Great Britain (England, Scotland and Wales) have been controlled by a domestic version of the old EU rulebook — retained Regulation (EC) No 1924/2006 — enforced through the Great Britain Nutrition and Health Claims (GB NHC) Register. Every claim that appeared on the EU’s Community Register as of 1 January 2021 was carried over into this new GB list. Anything not on it, or added to the EU list afterwards, is not automatically legal here.
Northern Ireland is the exception. Because of the Northern Ireland Protocol, EU food law still applies there, so labels sold into Northern Ireland are checked against the separate EU Register instead. A claim approved in the EU after the 2021 cut-off can be used on a label in Belfast but not, without a fresh GB application, on the same product sold in Bristol. If you’re comparing labels across the UK and Ireland and the wording differs, this divergence is very likely why.
The principle behind the register is simple: a claim has to describe a specific, evidence-assessed relationship between a nutrient and a normal body function — not a vague promise of wellbeing. To add a brand-new claim to the GB list, a manufacturer has to submit an application with supporting evidence to the relevant GB authority, and the UK Nutrition and Health Claims Committee gives a scientific opinion on it. That’s a slow, evidence-led process — which is exactly why so much shelf-copy sidesteps it.
What legally authorised wording actually looks like
Authorised claims are narrow and specific. They describe what a nutrient contributes to, not what the product will do for you as a person. A label can’t say “cures” or “prevents” anything — that crosses into a medicinal claim, which is a different, much stricter category. Here’s a sample of wording that is genuinely on the register, versus the kind of phrase that routinely isn’t.
| Authorised on the GB Register | NOT an authorised claim |
|---|---|
| “Vitamin C helps reduce tiredness and fatigue” | “Boosts your energy” |
| “Vitamin D helps support the immune system” | “Boosts immunity” / “Vitamin C helps prevent colds” |
| “Calcium helps maintain normal muscle function” | “Detoxifies the body” |
| “Magnesium contributes to the reduction of tiredness and fatigue” | “Eliminates stress” / “helps with brain fog” |
| “Vitamin B6 supports normal psychological function” | “Nootropic” / “adaptogen” used as standalone descriptors |
Notice the pattern: authorised wording is modest and mechanistic — it says a nutrient “contributes to” or “helps maintain” a normal function. The unauthorised column tends to promise an outcome, a feeling, or a cure. Generalised claims like “good for you” or “healthy” count as health claims too, and they’re only permitted if they’re tied to a named ingredient that has its own authorised claim behind it — a loose “healthy” badge on its own isn’t enough.
Why so many labels use the banned language anyway
Words like “boost,” “detox,” “focus” and “superfood” show up constantly on shelves and in adverts, despite not being authorised claims in their own right. Partly that’s because enforcement is reactive rather than pre-approval — nobody checks a label before it goes to print, so an unauthorised phrase can sit on packaging for years before anyone challenges it. Partly it’s because the line is genuinely subtle: a supplement legitimately containing vitamin D can say it “helps support the immune system,” but the moment the copy shortens to “boosts immunity,” it has quietly slipped from an authorised nutrient function into an implied outcome the register never approved. The gap between those two phrases is exactly where a lot of supplement marketing lives.
Claims that suggest a product can treat, cure or prevent a medical condition sit in an entirely separate, stricter bracket again, and are essentially off-limits for a food supplement regardless of what’s in the register. “Helps prevent colds,” claims about clearing acne, or promises of a specific weight-loss figure all fall into this territory. When a label crosses from describing a nutrient’s normal function into promising a medical result, it has left food law behind altogether.
How to check a claim yourself
You don’t need to take a label’s word for it. A few practical habits do most of the work:
- Read for the mechanism, not the promise. “Contributes to normal energy-yielding metabolism” is a real, checkable claim. “Energising” is not.
- Match the claim to a named nutrient. Authorised claims are always attached to a specific vitamin, mineral or substance at a stated quantity — not to the product as a whole.
- Be sceptical of anything implying a cure. Words like “treats,” “cures” or “prevents” a named illness shouldn’t appear on a food supplement at all.
- Watch for buzzwords standing in for claims. “Detox,” “superfood,” “nootropic” and similar terms are marketing shorthand, not verified functions, unless the label also spells out the specific authorised wording behind them.
If a claim looks like it’s overstepping, the UK’s Advertising Standards Authority is the body that handles complaints about misleading health advertising, and unauthorised or medicinal-sounding claims are exactly the kind of thing it can act on.
The bottom line
The GB Register exists so that a health claim on a supplement label means something specific and checkable, rather than whatever a copywriter felt like promising. Reading labels with this distinction in mind — authorised nutrient function versus implied outcome — is one of the simplest ways to tell a properly regulated product from one leaning on suggestion. That’s the same instinct this site has always argued for: the right to make an informed choice starts with knowing what a label is actually allowed to say.