Herbal medicines

Herbal medicines are those with active ingredients made from plant parts, such as leaves, roots or flowers. But being "natural" doesn't necessarily mean they're safe for you to take.

Just like conventional medicines, herbal medicines will have an effect on the body, and can be potentially harmful if not used correctly.

They should therefore be used with the same care and respect as conventional medicines.

If you're consulting your doctor or pharmacist about health matters, or are about to undergo surgery, always tell them about any herbal medicines you're taking.

Potential issues with herbal medicines

If you're taking, or plan to take, any herbal medicines, be aware of the following:

Certain groups of people should be particularly wary of taking herbal medicines.

Who should avoid herbal medicines?

Taking a herbal medicine may not be suitable for:

Speak to your doctor or pharmacist for advice before trying a herbal medicine if you fall into one of these groups.

Herbal medicines and surgery

It's important to tell your doctor if you take any herbal medicines before undergoing surgery.

This is because:

Your doctor may therefore advise you to stop taking any herbal medicines during the weeks leading up to your operation.

What to look for when buying a herbal medicine

If you want to try a herbal medicine, look out for a traditional herbal registration (THR) marking on the product packaging.

This means the medicine complies with quality standards relating to safety and manufacturing, and it provides information about how and when to use it.

But you should be aware that:

You can find THR-registered products in your local health shop, pharmacy or supermarket.

Risks of buying herbal medicines online or by mail order

The risks of obtaining fake, substandard, unlicensed or contaminated medicines are increased by buying medicines online or by mail order.

Unlicensed herbal medicines manufactured outside the UK may not be subject to regulation.

They may be copies of licensed medicines, but made in unlicensed factories with no quality control.

Some websites may appear to be legitimate, but are fronted by people pretending to be doctors or pharmacists. 

Herbal products sold online may also contain banned ingredients and toxic substances.

You can find a list of banned and restricted herbal ingredients on the GOV.UK website.

Herbal slimming products and products that claim to improve sexual performance, for example, are best avoided.

This is because they have been found to contain dangerous ingredients, including pharmaceutical ingredients, that aren't stated on the label.

Reporting side effects

You can report any side effect or adverse reaction to a herbal medicine using the Yellow Card Scheme run by the Medicines and Healthcare products Regulatory Agency (MHRA).

This can help the MHRA identify new side effects or risks associated with medicines, including herbal remedies.

You should report adverse reactions or side effects if:

It's important to include as much detail as possible, particularly any brand name or manufacturer's details relating to the herbal medicine.

In the past, Yellow Card reports have been used to identify interactions between St John's wort and other medicines, and to highlight the use of dangerous substances like mercury, lead and arsenic in unlicensed Ayurvedic and traditional Chinese medicines.

Page last reviewed: 18 October 2022
Next review due: 18 October 2025