Herbal remedies can cause harm


Because they are made up of natural herbs, people think remedies made from plants, flowers, leaves, berries, bark etc. must be safe.  But before you take ANY herbal supplement, you MUST check with your medical team that this won’t have any adverse effects on you.

Herbal remedies can be dangerous;  our ancestors knew this, and sometimes used them as poisons.  Some can react – dangerously with drugs and chemo, and no-one should take anything unless they tell their medical team first.

Mint from Project Gutenberg EBook of Culinary ...

Every day I receive e-mails telling me that this herbal supplement is magic – guaranteed to make me live longer, free me from cancer, give me better skin – you know the score!

I love herbs – use them a lot in cooking, but I am very, very careful about any herbal remedies that I swallow. According to the Medicines and Health Care Directorate  (MHRA), these remedies can react in surprising and sometimes dangerous ways, and need to be taken very carefully, under the supervision of a qualified person.

But to ‘mix and match’ remedies can be dangerous, and thousands of people poison themselves each year;  children are especially vulnerable.

Shops and catalogues sell ‘natural foods’ and ‘natural remedies’ to make money.  Drug companies also sell their products to make money, and these are some of the most profitable companies in the world.

However, there is a difference.  Until recently Herbal remedies could be sold without any trials having taken place –  drugs cannot be prescribed unless there have been clinical trials in a controlled environment, rigorously supervised.  Yes, there can be horrendous problems with drugs, but if there is a problem this is flagged up immediately, as I found when I reported to one drug company that I had carpal tunnel syndrome after taking their product.

However, the EU has now taken a stance, much against the wishes of the herbal remedy producers.  To a  certain extent I have sympathy with them, as many have been supplying simple remedies for years, sometimes even centuries, that are relied on by millions.  From 2011, new regulations come in to force, and as with all EU laws, some of the small but good companies will be forced to close, unable to afford the draconian steps that will go towards compliance.

However, the good side is that there should be more transparency and better safety in place.  e.g. Ayurvedic medicine may contain lead, copper, iron, gold, silver, mercury, tin and zinc. Chinese herbal medicine uses Mercury compounds in prescriptions for tranquillizing and anti-convulsant treatment, hypnotic effects and ulcers.  We need to know before we buy.

People combining orthodox drugs with natural remedies could have some very nasty side effects. For instance, I am told  corticosteroids may be included in herbal products without being declared on the label or other product literature.  Even Green Tea, which contains vitamin K, can antagonise Warfarin and increase the risk of heart palpitations and thrombosis.

So before taking any supplement, take advice from

MHRA (THE MEDICINES AND HEALTHCARE PRODUCTS REGULATORY AGENCY), who have issued the following general safety advice to consumers using herbal medicines

  1. Remember that herbal remedies are medicines.
  2. As with any other medicine they should be used with care.
  3. Any medicine – herbal or otherwise – has the potential to have adverse effects.
  4. Before you take any herbal medicine you need to be sure it is the correct product for you.
  5. Remember that natural does not mean safe.
  6. Many plants can be poisonous to humans.
  7. Many pharmaceutical medicines have been developed from plants because of the powerful compounds they contain.
  8. Herbal remedies can interact with other medicines. This could result in the other medicines having reduced or enhanced effects, including side-effects.
  9. When consulting your doctor or pharmacist about your health always tell them about any herbal medicines you are taking.
  10. As with all medicines, keep herbal medicines out of the sight and reach of children.

Are any particular groups at risk?

In many cases the safe use of herbal medicines has not been established in:

  • pregnant women
  • breastfeeding mothers
  • children
  • elderly.

Therefore caution should be taken about use of herbal medicine in pregnancy, when breast feeding or in children/elderly.

If you are due to have a surgical operation always remember to tell your doctor about any herbal medicines you are taking. Some herbal medicines could alter the effects of anaesthetics or other medicines during surgery.

Anyone with a history of liver complaints or any other serious health condition is advised not to take any herbal medicine without speaking to their doctor first.

Which herbal medicines have been assessed by the Regulator?

Look for the PL or THR number on the product labels. Licensed herbal medicines have a Product Licence (PL) number. Under a new scheme products with a Traditional Herbal Registration (THR) number will come on to the UK market in the coming months. Both these kinds of medicines are regulated by the MHRA and meet assured standards. Other herbal medicines on the UK market have not been assessed by the MHRA.

How can I tell if an unlicensed medicine is made to acceptable standards?

Consumers should be aware that unlicensed herbal medicines on the UK market have not been assessed by the MHRA as to their safety, quality or patient information. The MHRA say there is evidence that standards vary considerably in the unlicensed sector. It is likely that some companies manufacture products to good standards. However, there is also evidence of poor or patchy standards in parts of the sector. Information about this is regularly published on the MHRA’s website. www.mhra.gsi.gov.uk

It is not generally possible for consumers to identify which unlicensed medicines are made to acceptable standards. However, there are a number of pointers, in particular from the product information, which may be indicative of poor or unreliable standards.

Advice for consumers when buying unlicensed herbal medicines

Treat with caution claims about safety that are not backed by credible evidence. Be wary of products making claims such as :

  • The herbal remedy is “100% safe”
  • Herbal remedies are “safe because they are natural”
  • This herbal medicine “has no side effects”
  • “Chinese medicines will not interfere with the effects of any western medicine”
  • You can avoid Chinese medicines interfering with other medicines if you take them an hour apart.

Be wary of any unlicensed medicine suggesting the consumer should stop taking, or change the dosage of, a prescribed medicine. The MHRA advise you not to follow such advice – you should always consult your doctor about making changes to your prescribed medication. Treat with caution any unlicensed herbal medicine that makes medicinal claims for the product (that is claims to prevent, treat or cure illnesses). These claims will not have been assessed by the MHRA and could be misleading

Be wary of any product if:

  • It is not labelled in English
  • It does not have information about safe usage
  • The herbal practitioner cannot or will not give a list of ingredients.

Apparently similar unlicensed herbal medicines may be accompanied by different patient information. Do not assume that the medicine with fewer warnings is necessarily safer to use.

Buying herbal medicines over the Internet

  • There is an international trade in poor quality unregulated herbal products. Unlicensed “herbal” products in the UK and elsewhere have been found containing banned pharmaceutical ingredients or heavy metals.
  • Products may contain harmful herbs that are not permitted in the UK. 
  • Be aware that unlicensed herbal medicines manufactured outside the UK may not be subject to any form of effective regulation.
  • If a product refers to licences granted in other countries there may be no guarantees that the product actually complies with requirements or that standards applied in other counties match those that a UK consumer would expect from regulated products.

What to do if you think you have had an adverse reaction to your herbal medicine?

All medicines, including herbal medicines, may cause side effects or unwanted reactions. If you think you have had a reaction to your herbal medicine, you should discontinue use and tell your doctor or pharmacist.

If you think you or someone else has had an unwanted or harmful reaction after taking a herbal medicine (commonly referred to as a suspected adverse drug reaction), the MHRA say they would like to know. This will help us give advice to other patients and healthcare professionals – and will help us make sure herbal medicines in the UK are safe. You can report a reaction yourself directly to us using a system called the Yellow Card Scheme. This can be done online or by filling out a paper yellow form which is available upon request by calling 020 7084 2000. Alternatively, you can ask your doctor or pharmacist to report the reaction us on your behalf.

Herbal Safety News – Current issues
Follow the hyperlink below to all the latest cases that we have received.


Traditional Herbal Registration Scheme.

Herbal Medicines – What we do

There is a steadily growing body of evidence to show that some unlicensed herbal remedies are not produced to high quality or safety standards, with for example, instances of banned, dangerous or mis-identified ingredients regularly being found and highlighted on the Agency’s Herbal Safety News pages. In October 2005, new regulations (the Traditional Herbal Registration Scheme) were put in place to enable the Agency to assess and authorise traditional herbal products for sale in the UK before they are placed on the market. Purchasing products registered under this scheme will mean that consumers will; have assurance as to the quality and safety of traditional herbal medicines, be able to make an informed choice about which products to use, as registered products will provide full and reliable information on the intended, safe use of the product. No medicine is risk-free. Underpinning all the Agency’s work is fact-based assessments of whether the benefits to patients and the public outweigh any potential risks associated with the use of the medicine.


For many years most herbal remedies on the UK market where sold as unlicensed medicines under section 12 of the Medicines Act 1968. This legislation provided very little in the way of safeguards and meant that the products could be sold with little regard to safety, quality or to the provision of useful patient information. Alongside the unlicensed sector sat several hundred licensed herbal medicines. On the market before the introduction of the medicines licensing system, these products were originally given a product licence of right which was subsequently reviewed and converted into a full product licence.

In recent years, we have seen a substantial growth in the popularity of over-the-counter (OTC) herbal medicinal products; due in part to the public’s belief that herbal and natural products are safer than what are seen as “synthetic” medicines.

Alongside the increased popularity and regular usage of herbal medicines has been an increase in understanding about the possibilities for side effects and interactions between herbal and other medicines; growing concern about the safety and quality of some unlicensed products and about the lack of reliable information; as well as concerns about the professionalism of some practitioners.

Headline catching incidents have highlighted adverse, sometimes life threatening, effects which have resulted from use of OTC herbal medicinal products tainted with anything from microbial contaminants, heavy metals, chemical toxins, or adulterated with pharmaceutical drugs.

In the 1990s a major incident in Belgium prompted increased international awareness of the safety issues surrounding the use of herbal medicines. In this case over a hundred women suffered kidney damage and many went on to develop cancer, following the supply of slimming aids containing the toxic herb Aristolochia.

Evidence, such as this, and the regular cases of products found to contain high levels of heavy metals, and other illegal non-herbal ingredients points to an international trade in low grade herbal medicines. Many such products are sold with illegal medicinal claims whereas the product has not been assessed by a regulatory authority and there is no evidence to show that the product is safe or even contains the stated ingredients.

With the historic lack of a systematic regulatory scheme, requiring specific quality standards it was left up to each manufacture to decide what standards, if any, to follow. Responsible manufacturers found they were being undercut by those operating to very low standards.

The MHRA recognises that many unlicensed herbal medicines on the UK market are manufactured to reasonable standards. But even where this is the case, concerns about the inconsistency in information provided for patients about the safe usage of the product remains a major concern. Herbal medicines, like any other medicines, can have adverse (side) effects and interact adversely with other prescription medicines; this needs to be made clear.

The main problem is that it is impossible for the public to identify which unlicensed herbal medicines are made to acceptable standards.

The EU Directive on traditional herbal medicinal products

The Traditional Herbal Medicinal Products Directive (THMPD) 2004/24/EC establishes a regulatory approval process for herbal medicines in the European Union (EU). It requires each EU Member State to set up a traditional herbal registration scheme, for manufactured traditional herbal medicines that are suitable for use without medical supervision.

The UK Traditional Herbal Medicines Registration Scheme came into force 30 October 2005.

Under these regulations, a company needs to demonstrate the safety of the herbal medicine by providing bibliographic evidence of a minimum of 30 years of traditional use for the product. At least 15 of the 30 years must have been within the EU. This replaces the requirement to demonstrate efficacy and serves as the basis for permitting minor therapeutic claims; regulators can however ask for more data where they have any specific safety concerns. Further, the herbal medicine must now be manufactured under GMP (Good Manufacturing Practice), pharmacovigilance requirements apply as do the normal rigorous quality standards for medicines with a Marketing Authorisation (MA). Patient information is as for any typical over the counter medicine; in addition there is a requirement for a statement on labels and in advertisements that the indication (medicinal claim) is based on traditional usage.

The MHRA will continue to take robust regulatory action against a minority of operators who ignore even the existing limited legislation for unlicensed herbal medicines and so jeopardise public health and the reputation of the sector. The recently established independent expert advisory committee, the Herbal Medicines Advisory Committee, will strengthen MHRA’s capacity to respond to the many challenges ahead.

Herbal products registered under the new scheme

Below is a link to the products which have been registered



Q: If a new herbal medicine was launched on the market today, would it have to be registered?

Yes, a manufactured over-the-counter herbal medicines would require a product licence – either in the form of a traditional herbal registration or a marketing authorisation.

Q: Do ALL herbal medicines have to register under the new registration scheme?

Yes. As a result of Directive 2004/24/EC, all over-the-counter herbal medicines in the UK, will require either a Traditional Herbal Medicines Registration (THR) or a full Marketing Authorisation (MA). Although products legally on the market prior to 30 April 2004, which complied fully with the requirements of Section 12(2) of the medicines Act 1968, will benefit from transitional protection and can be sold as unlicensed herbal remedies until 30 April 2011.

MHRA 020 7084 2000 (weekdays 0900 -1700);  020 7210 3000 (other times)
Fax: 020 7084 2353 info@mhra.gsi.gov.uk

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