The boundaries between medicines and other products are becoming increasingly blurred, presenting new challenges to regulators.

When we think of medicines, products such as paracetamol, antibiotics or anti-cancer drugs probably spring to mind. But medicines encompass many different things, such as vaccines and barium meals, and increasing numbers of borderline products also claim health benefits.

The regulatory bodies charged with overseeing and granting licences to new medicines must assess many different products:

• Under the Medicines Act, a medicine is defined as "any substance or combination of substances which may be administered to human beings or animals with a view to making a diagnosis or to restoring, correcting or modifying physiological functions in human beings or animals".
• Appliances, instruments and devices are classed not as medicines but as medical devices. They also come under the Act. The range of products is very wide, from syringes and dressings to surgical instruments, hospital beds and walking frames – even condoms and contact lenses.

The term 'medicine' encompasses many different types of therapeutic products.

Borderline products

The boundaries between medicines and other products are becoming increasingly blurred, especially because the legislation covers marketing claims made for products such as 'fighting' or 'protecting against' a disease.

Products such as disinfectants or cosmetics are not normally regarded as medicines and so do not require a license in the UK. Similarly, food supplements containing additives such as vitamins or minerals generally come under food safety and labelling legislation.

But if any of these contains a pharmacologically active substance or makes medicinal claims (for example, claiming to lower cholesterol or calm anxiety), it may require a licence before it can be released onto the market.

Herbal medicines

Herbal remedies are classified as medicines. As public interest in complementary medicine has led to increased demand and an influx of new remedies from many countries and medical traditions, their regulation has come increasingly under the spotlight in Europe. A few traditional medicines, such as the herb kava-kava used in medicines and food supplements to combat anxiety, have been banned following Yellow Card alerts on serious adverse reactions.

Herbal medicines present a problem for licensing as the system is designed to assess chemical entities not whole plants (such as garlic or St John's Wort). A EU Directive (Directive on Traditional Herbal Medicinal Products 2002) waived the requirement for traditional herbal medicines to undergo double blind clinical trials, if they can be shown to have been in safe continuous use for 30 years in the EU.