UK MHRA Guidance: Borderline Products: How to Tell If Your Product Is a Medicine

In the ever-evolving world of pharmaceutical and medical product regulation, correctly classifying your product is crucial. Some products fall into a “grey area” where they could be regulated as a medicinal product, a medical device, or another type of product such as a cosmetic, food supplement, or biocide. To help manufacturers and other stakeholders make this determination, the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) publishes detailed guidance on how to decide whether a product should be regulated as a medicine.

The Borderline Products: How to Tell If Your Product Is a Medicine guidance was initially published on 6 January 2021 and was last updated on 12 January 2026, reflecting the MHRA’s current thinking on borderline medicinal products.

Introduction

Some products are straightforward to classify — for example, human insulin clearly falls under medicines, while a stethoscope is clearly a medical device. However, many products blur the line between categories.

What Is a Borderline Product?

A borderline product is any product whose regulatory status is unclear or uncertain because it may satisfy the definitions of more than one product category. For example, a herbal preparation presented with claims about treating disease might be a medicine even if it resembles a food supplement.

According to MHRA, the key types of products that may be considered borderline include:

• Cosmetics

• Food products/food supplements

• Herbal products

• Biocides

• Machinery or laboratory equipment

• Products potentially regulated as medical devices or medicines

Because the same product might appear similar to a medicine in one context and different in another, MHRA emphasises that classification depends on regulatory criteria, not market perception or international status. For example, just because a product is classed as a medicine in another country does not guarantee it will be treated as such in the UK.

Definition of a Medicinal Product

Under UK law, a product is considered a medicinal product if it meets one or both of the following criteria:

1. Substance Presentation: It is presented as having properties for preventing or treating disease in humans.

2. Mode of Action: It may be administered to people with the intention of restoring, correcting or modifying physiological function by exerting a pharmacological, immunological, or metabolic action, or used for medical diagnosis.

If a product’s intended purpose and mode of action fall within these definitions, it is likely to be classified as a medicine and subject to the Medicines Regulations (e.g., licensing, labelling, safety monitoring).

How the MHRA Decides If a Product Is a Medicine

The MHRA uses a structured approach to determine whether a borderline product should be regulated as a medicinal product. The key factors considered include:

1. Intended Purpose

This refers to what the manufacturer claims the product does — both explicitly (in labelling, packaging, promotional materials) and implicitly (by how the product is presented to users).

2. Mode of Action

MHRA assesses how the product achieves its effect, focusing on whether its primary mechanism is pharmacological, immunological, or metabolic. A product that primarily works through these mechanisms is more likely to be a medicine.

3. Presentation of the Product

How a product is labelled, marketed, or described significantly affects its classification. Even a product with no active pharmacological ingredient could be classified as a medicine if the manufacturer makes therapeutic claims.

4. Similar Products on the Market

Comparisons with products already regulated in the UK can guide classification, but these comparisons are not determinative — MHRA still makes independent judgments based on evidence.

What Happens After Classification?

Once MHRA determines that a product is a medicinal product:

• It must comply with UK Medicines Regulations.

• The manufacturer must obtain relevant licensing (Product Licence/MA) before marketing.

• Labelling, safety monitoring, and post-market obligations apply accordingly.

Conversely, products that do not fall under the definition of a medicine remain regulated under their appropriate frameworks (e.g., cosmetics law or medical device regulation).

How to Get Regulatory Advice

If a manufacturer is unsure whether their product is a medicine, the MHRA encourages them to seek guidance. This often involves:

• Providing product details

• Describing its intended purpose

• Explaining mode of action and presentation

MHRA can then offer a formal opinion on classification, which helps manufacturers decide the correct regulatory pathway.

Correct classification ensures compliance with appropriate regulatory frameworks and protects public health by placing products under proper safety oversight.For complete guidance on borderline product classification and regulatory requirements, please refer to the official MHRA guidance here:

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