Buying Good Quality Herbal Products

Having a THR (Traditional Herbal Registration) logo on your herbal tablets ensures good quality. Back in the 1990s there was continuing evidence of low grade, and, sometimes, dangerous unlicensed herbal products on sale in the UK. These lacked any product information – not even an indication for what condition to use them for - so consumers were not made aware of potential interactions with other medicines, side effects or if it was safe for children or pregnant women. In 2004, the THR scheme was introduced throughout the EU and, although complying with its stringent requirements has been a steep learning curve and a costly exercise for manufacturers, we now have reassurance that products on sale with a THR logo are of good quality.

The THR scheme has been a great success and will continue to be in place whatever Brexit throws at us! Standards for safety, quality and reliable patient information are key requirements, and agreed medicinal claims are allowed on the label of the final product. However, indications for use are only allowed to include minor, self-limiting conditions, which are appropriate for self-care. Of course, professional prescribing by herbal practitioners of these same herbs may go well beyond these indications.

Although granting a THR is dependent on a history of use of a herb and not on research evidence of its efficacy, that does not mean that there is no scientific evidence for its health benefits. While there will be at least some evidence from laboratory studies for all herbs with a THR, for many of the key herbs there is also clinical trial data, which I am trying to highlight in these Friday blogs. If you are thinking of buying a herbal product over-the-counter, make sure it has a THR logo! (You can find more information about THR herbals via the BHMA's website.)


Ann Walker PhD, FCPP, MNIMH, RNutr
Course Director DHM
Herbal Practitioner

Vitex for PMS/PMT

Article and Photo © Ann Walker

The berry of Vitex agnus-castus - or agnus-castus, as it is commonly known - is a key herb used in western herbal medicine, largely for women’s health. Its main applications are to support hormonal balance and normalise aberrations of the menstrual cycle, including alleviating symptoms of pre-menstrual syndrome/tension (PMS/PMT).

A team from the Netherlands combined (or ‘pooled’) results from 14 randomised clinical trials looking at the effects of Vitex for PMS (PMID: 28237870). They found a very large positive effect of the herb on PMS symptoms compared with placebo. However, they were very cautious in the interpretation of these findings, as the studies which were pooled together varied in design, dosage, quality of the preparations used and the methods of measuring PMS. The researchers concluded that while the pooled results showed a strong positive therapeutic effect of Vitex for treating PMS, there was still need for high-quality trials on Vitex for PMS patients using standardized extracts of the herb versus placebo or versus modern drugs like anti-depressants or oral contraceptives.

From being involved in studies of PMS myself (PMID: 9861593), I know that even taking a placebo, can result in up to 30% reduction in symptoms. So, trying to find an effect of an intervention like Vitex is not easy as it has to be more than the placebo effect. The large response to Vitex reported against placebo here is, therefore, impressive. Although not providing the ultimate proof of efficacy, these results, nevertheless, are still supporting data for the traditional view of Vitex as a useful herb to achieve hormonal balance in women and the herb is remains freely available for purchase in retail outlets.

PMID = PubMed identifier

Ann Walker PhD, FCPP, MNIMH, RNutr
Course Director DHM
Herbal Practitioner

Herbs for Anxiety

Article Ann Walker; Photo © Debs Cook

Many modern drugs, prescribed by doctors for anxiety, work by raising the level of a neurotransmitter in the brain called GABA (gamma-aminobutyric acid). GABA is the chief neurotransmitter that reduces brain-cell over-activity. By increasing the amount of GABA, drugs can typically have relaxing, anti-anxiety and anti-convulsive effects and can be very effective. However, long-term use of modern medications can have unwelcome side effects such as slower mental function and withdrawal symptoms.

A research group from Australia were interested in finding whether plant extracts with a history of safe use as medicines, might act in a similar way to these drugs (PMID: 29168225). They scoured the literature to find herbs that had been shown (a) to raise GABA levels in test-tube studies, (b) to reduce anxiety in lab animals and (c) to reduce anxiety in human studies. Ten herbs met these three criteria: Kava, Valerian, Gotu Kola, Hops, Chamomile, Ginkgo Biloba, Passionflower, Ashwagandha, Skullcap and Lemon Balm.

I know from clinical practice that herbal medicines can play an enormous part in supporting mental health and alleviating conditions such as anxiety. After starting my herbal practice, it was the strong positive influence that some herbs can have on mental function that was the thing that astonished me most in dealing with patients – something not highlighted in my training. All the herbs mentioned in this current review are well known to western herbal practitioners and nearly all would feature frequently in their herbal prescriptions. It’s great to see research revealing actual mechanisms of action to support the traditional use of these herbs!

PMID = PubMed identifier

Ann Walker PhD, FCPP, MNIMH, RNutr
Course Director DHM
Herbal Practitioner

Herbal Mix Alleviates PCOS Symptoms

Article & Photo © Ann Walker

Characterised by menstrual irregularities and often accompanied by the development of secondary sexual male characteristics, PCOS (polycystic ovarian syndrome) is a complex female condition, which is sometimes called a pre-diabetic state. Changes in diet and lifestyle aimed at weight loss should always first-line treatment for PCOS sufferers and can work well if strictly followed. However, to be successful, many women seek further support, particularly from herbal medicine.

In Australia, Professor Alan Bensoussan’s pioneering research team conducted a randomized controlled trial on 122 over-weight women with PCOS (PMID: 29178904). They divided them into two groups – one group was given lifestyle advice plus daily doses of herbal medicine and the other given lifestyle advice alone. The herbal medicine comprised Cinnamon, Liquorice, St John’s Wort, Peony Rroot and Puncture Vine.

After three months, menstrual regularity was greatly improved in the group taking the herbal medicine, compared with the control group. Furthermore, secondary outcomes of body weight, blood insulin, luteinising hormone (a hormone from the pituitary which helps to regulate the menstrual cycle), blood pressure, quality of life (reduction in depression, anxiety and stress) and pregnancy rates (among a sub-group wishing to become pregnant) were all significantly better or improved for those taking the herbs.

Prescribing mixtures of herbs, with several physiological actions, as used here are, is common practice among herbal practitioners. This approach is especially useful for conditions like PCOS with multiple presentation. In this study, liquorice and peony root were used to reduce the influence of testosterone, cinnamon to improve insulin sensitivity, St John’s wort to aid the resolve to lose weight, and puncture vine to aid hormonal balance.

PMID = PubMed identifier

Ann Walker PhD, FCPP, MNIMH, RNutr
Course Director DHM
Herbal Practitioner