How to make compliant health claims on supplements in the UK

Making health claims on supplements in the UK is not simply a matter of writing copy. There are three distinct regulatory layers that apply, each with different requirements and different consequences for getting it wrong. Most brands are only aware of one.

This guide explains what each layer requires, where the lines are, and what clinical evidence actually buys you in practical terms.

The three regulatory layers

Before getting into each layer, here is the short version:

• The GB authorised health claims register defines a specific list of approved nutrient-function claims. If your nutrient is on the list and present at the required level, you can make those exact claims without additional study evidence.
• The ASA and CAP Code govern advertising. Any health claim in a paid ad, on a website, or in marketing material must be substantiated before it appears.
• The MHRA draws the line between a food supplement and a medicinal product. Cross it and you need a product licence.

These three layers overlap, and compliance with one does not guarantee compliance with the others.

Layer 1: The GB authorised health claims register

Following Brexit, the UK retained EU Regulation 1924/2006 on nutrition and health claims. The GB register lists several hundred approved claims for specific nutrients, each with a defined wording, a minimum ingredient level, and conditions of use.

Examples of authorised claims:

• "Vitamin D contributes to the normal function of the immune system."
• "Magnesium contributes to normal energy-yielding metabolism."
• "Omega-3 fatty acids contribute to the maintenance of normal blood triglyceride levels."

If a claim is on the register and your product contains the relevant nutrient at the required level, you can make it. No clinical trial required.

The limitation: authorised claims describe what a single nutrient does in the body. They do not allow you to make claims about your specific formula, your product's efficacy compared to competitors, or outcomes beyond what the approved wording permits. If you want to say "our formula improved cognitive function in a 12-week study," you need clinical evidence specific to your product.

Layer 2: The ASA and the CAP Code

The Advertising Standards Authority (ASA) enforces the UK Code of Non-broadcast Advertising (CAP Code), which applies to ads, websites, social media, and marketing emails. The key rule for supplement brands is CAP Code section 15, which covers health and beauty claims.

The ASA's standard for health claims is straightforward: evidence must exist before the claim is made. The burden is on the advertiser, not on the regulator.

What counts as sufficient evidence depends on the claim:

• Authorised nutrient claims from the GB register are generally accepted by the ASA without additional evidence, provided they follow the approved wording exactly.
• General function claims about your product (e.g. "clinically shown to support joint mobility") require published, peer-reviewed evidence. For most such claims, the ASA expects a randomised controlled trial.
• Comparative claims (e.g. "more effective than leading competitors") require head-to-head evidence.

When the ASA upholds a complaint, the outcome is public. Upheld rulings are published on the ASA website and remain searchable. A single upheld ruling can create lasting reputational damage, complicate retail buyer meetings, and trigger further scrutiny from the MHRA.

Layer 3: The MHRA and the medicinal claims boundary

The MHRA regulates medicinal products. A product becomes medicinal either by its composition (contains a pharmacologically active substance at a relevant dose) or by its presentation: the way it is described implies it can treat, prevent, or cure a disease.

For supplement brands, the risk is almost always in presentation. Claims that cross the line include:

• "Reduces blood pressure"
• "Prevents colds and flu"
• "Alleviates symptoms of anxiety"
• "Clinically proven to treat joint pain"

These claims describe disease treatment or prevention. Making them on a supplement that does not hold a medicinal product licence is an offence under the Human Medicines Regulations 2012. The MHRA can require product withdrawal, seize stock, and refer cases for prosecution.

The distinction that matters: "contributes to normal immune function" (describing normal physiology) is a safe authorised claim. "Boosts immune response to prevent infection" (implying disease prevention) is medicinal territory.

What major retailers require

Boots and Holland & Barrett both operate commercial evidence requirements that go beyond regulatory minimums. Both have science or technical teams who review product submissions and can ask for substantiation for specific claims before ranging a product.

In practice, having published clinical evidence for your formula is the fastest way through a retail buyer meeting. Brands that arrive with a peer-reviewed study can make claims that competitors with generic ingredient-level evidence cannot. Our dedicated guide covers what Boots and Holland & Barrett specifically require.

How clinical evidence changes your options

Clinical evidence on your specific formula does three practical things:

1. It unlocks claims beyond the authorised register. With a published study, you can make claims about your product's performance that authorised wording alone does not cover.
2. It protects you if challenged. If the ASA investigates a claim, a published peer-reviewed study is the strongest possible defence. Brands with evidence are rarely the target of successful complaints.
3. It signals seriousness to retailers and partners. A study is a concrete signal that your formulation works and that you stand behind it. Retail buyers and investors respond to this differently than they do to claims backed only by ingredient-level data.

The claims that drive the most commercial value, such as "clinically shown to improve X in Y weeks," are only available to brands with published evidence specific to their formula. Authorised claims are available to every brand that includes the same nutrient. Your study is yours alone.

Practical compliance checklist

Before publishing any health claim, check the following:

• Is the claim on the GB authorised health claims register? If yes: use the approved wording exactly and confirm the nutrient is present at the required level.
• Does the claim refer to your specific formula or outcome? If yes: you need a published clinical study specific to your product.
• Does the claim describe the prevention, treatment, or cure of a disease? If yes: stop. This is medicinal territory without a licence.
• Is the evidence in place before the ad goes live? If no: the claim is not compliant, regardless of whether the evidence is planned.
• Is the evidence published in a peer-reviewed journal? Unpublished studies, internal data, and citations of third-party research on the same ingredient are generally not sufficient for formula-specific claims.

Frequently asked questions