St John's Wort

Studies show it helps relieve mild depression, but can you be confident the brand you buy will work?
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  • Updated:13 May 2005

01 .Introduction


In brief

  • St John's wort (SJW) may be a useful part of a treatment strategy for mild depression.
  • However, not all SJW products are equal, and lack of transparency about their products on the part of companies that supply them makes it difficult to know which can be used with confidence.

Please note: this information was current as of May 2005 but is still a useful guide today.

There's good evidence that products containing preparations of the herb St John's wort (SJW) can be useful for the treatment of mild depression. Many studies looking at short-term use of SJW have found its better than a placebo and as effective as some antidepressants, with fewer side effects.

However, not all preparations containing SJW are created equal: the final product can vary according to the growing conditions for the herb, the plant parts used, time and method of harvest, extraction and other manufacturing processes, and storage.

The active ingredients in SJW aren't known exactly, nor is it known what levels of even the suspected actives are needed to be effective. This makes it difficult to create a standard for an effective preparation, although there are some guidelines for extraction processes and minimum levels of key components.

Complementary medicines in Australia haven't traditionally been subjected to the same level of pre-market evaluation for effectiveness as conventional pharmaceuticals, and post-market surveillance tends to occur on a random basis or when issues arise with particular products or manufacturers.

Yet consumers and health professionals interested in using SJW for mild depression need to be confident that products sold in Australian pharmacies, supermarkets and healthfood stores are equivalent to the effective products reported on in medical studies.

We took a look at SJW and the herbal medicines industry to determine what level of confidence we can place in its products. In particular, we were interested in the kinds of claims manufacturers are making, and the evidence they have to back up their claims. We also tested some products to try to check the levels of suspected active ingredients, although this wasn't quite as straightforward as we'd hoped - see Chemical conundrums, for more.

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Generally speaking, the stronger the claims that are made, the more rigorous the evidence has to be.

Labels on the SJW products we looked at don't mention the word depression, because making claims about treating or managing depression would be considered very strong and required to be backed up with the highest level of evidence.

This involves considerable trouble and expense, and perhaps from a company's point of view may not even seem necessary – after all, SJW's potential benefits for mild depression are widely known, so why not avoid the direct claim and with it all the bother?

Some products do list symptoms linked to depression for which the product may be a useful remedy, such as "low mood and despondency" and "feelings of sadness and/or tearfulness". By and large, though, you'll find the label claims typically relate to the relief of stress and anxiety. One of SJW's known effects is to reduce anxiety, which can be a symptom or precursor of depression as well as being a condition in its own right.

Any substantial claims should ideally be backed up with good-quality scientific evidence based on clinical trials showing the product's effectiveness. If the product in question hasn't itself been tested, the Therapeutic Goods Administration (TGA) says it's acceptable for the 'sponsor' (the product's manufacturer or distributor) to provide evidence based on trials of other products identical to, or not substantially different from, its product – as long as the sponsor can show this to be the case.

Where's the evidence?

A therapeutic product that's 'listed' by the TGA is allowed to be sold in Australia on the basis that it meets certain safety and quality criteria. As of April 1, 2004, the TGA has required sponsors of listed medicines, including herbal medicines, to hold evidence for claims and indications they make about their products. However, up to now they haven't had to actually produce it until or unless asked. So we figured all we had to do was ask sponsors to show us their evidence, and given that they'd be bound to have it readily to hand (in case the TGA comes knocking on the door), they'd simply have to pop something off to us in the mail.

We invited the sponsors of 27 SJW products to do this: we received evidence for 14; five companies refused to take part, claiming commercial confidentiality as a reason (and one was concerned CHOICE would give it a negative report regardless of what evidence it gave us!); and we didn't hear from the last eight at all, despite contacting them numerous times. See The evidence – who provided what, below, for the brands and sponsors we looked at.

Evaluating the evidence

We asked three people with expertise in the fields of herbal medicines, pharmacology and/or psychiatry to evaluate the quality of the evidence provided to determine whether it backed up the claims made.

As mentioned earlier, sponsors can provide evidence based on products similar to their own, as long as they can prove their similarity. But it can be difficult to prove that one manufacturer's Product A is essentially the same as another manufacturer's Product B that was used in published clinical trials. If they use the same extract (that is, the same SJW source material) at the same dose, equivalence can be shown. Otherwise, there's little option but to test Product A itself to ensure scientific rigour.

Comprehensive evidence was provided for CHEMISTS' OWN, FLORDIS Remotiv, GUARDIAN PHARMACIES, HERRON, HILTON HEALTHSTREAM and MEDIHERB products. Their sponsors provided evidence based on the final product or on the extract used in their product (see The evidence – who provided what, below).

The evidence provided by the rest of the companies that sent us any may adequately meet the TGA evidence requirements (there appears to be some latitude for interpretation). However, they didn't provide us with evidence that contained a clear link between their product and one shown to work in a clinical setting. This doesn't necessarily mean their products don't work just as well as those that gave us comprehensive evidence – just that the evidence given to us wasn't as strong.

As for the companies that didn't take part, they may well have evidence to back up their claims – they just didn't give it to us.

The evidence - who provided what

Comprehensive evidence was provided to back up claims for the following products:

  • Flordis Remotiv, where evidence was based on published papers of clinical trials of the product, which was shown to be effective for mild depression. There's enough information provided on the packaging for a consumer to do their own search for evidence in the medical literature.
  • Chemists' Own, Guardian PHARMACIES, Herron, Hilton Healthstream and Mediherb, where clinical trial evidence was based on products using the same dose of the particular SJW extract used in these products (although the extracts are confidential). Evidence also showed that the product was effective for mild depression.
  • The sponsor of THE HERBALIST (NATURAL HEALTH CONCEPTS) makes claims based on evidence of traditional use, and therefore isn't required to provide scientific evidence, though the evidence provided meets the TGA requirements for traditional use. It also provided details of the extract used, and it's one for which good scientific evidence exists.
  • Evidence for the following brands was considered 'incomplete': the evidence provided consisted of the name of the extract, but not evidence to back up claims made; or evidence that SJW works, but no clear link between that evidence and the particular product. In some cases this was for reasons of 'commercial confidentiality':
    AMCAL, CENOVIS, HERB VALLEY (sponsored by Essential Nutrients), Golden Glow, Nature's Own, NATURE'S WAY (Pharm-a-care), SYAZAK (Swisse Vitamins).
  • The following companies refused to take part in our evaluation of evidence, citing commercial-in-confidence or other reasons:
    Australian NaturalCare Products, Blackmores, Green Valley Nutrition (GNC), Herbs of Gold, Hilde Hemmes.
  • The following companies didn't respond to our request for evidence:
    Bioforce Australia (HYPERIFORCE), Blooms Health Products, Direct Nutritional Supplies (VIGA-VITA), Health World Limited, Healtheries of Australia, Nutrition Care Pharmaceuticals, TP Health (GREENRIDGE), Weleda Australia.

03.A place for St. John's Wort?


It's likely that a large number of the people being prescribed antidepressants could benefit from those SJW preparations that are backed up by good evidence for clinical effectiveness. Obviously if the TGA and manufacturers work together to ensure all products available on the shelves are good-quality, effective preparations, this will make things a lot easier for consumers and health professionals.

Benefits of SJW vs drugs include similar efficacy, lower cost (to the individual and the health system), fewer side effects and less risk of dependence. One of the main problems with conventional antidepressants for people with mild depression is that the side effects can reduce the likelihood of sticking with them.

However, simply swapping a conventional medicine for a herbal one doesn't resolve the 'pill for every ill' mentality, and doesn't provide a long-term solution, which is likely to involve making changes to thought patterns and life circumstances, and learning to deal with crises.

Ideally, perhaps, anyone suffering from mild depression would have access to whatever treatment was judged most appropriate, whether counselling, psychological therapies or medication (conventional or SJW) - alone or in combination. The reality, however, is that the provision of resources required for counselling and psychological therapies is inadequate, and for many people medication will be the primary treatment.

There are concerns about interactions of St John's wort with other medications, especially for people who self-medicate with SJW without their doctor's knowledge. But as long as you make your doctor aware of all medications (herbal and conventional) you're taking, most people can use it safely.

Chemical conundrums

Various chemicals in SJW have been found to show biological activity, and any or all of these may play a role in the antidepressant effect. The main chemicals include hypericin, pseudohypericin and other hypericins; hyperforin; and various flavonoids. SJW products have the amount of total hypericins listed on the label, and sometimes the amount of hyperforin.

The antidepressant effect was originally thought to be related to levels of hypericin, and more recently hyperforin, but a trial using a flavonoid-rich extract with no hypericin or hyperforin still found some antidepressant effect. This suggests that SJW's effectiveness is based on the product in its entirety, with compounds working together in a synergistic fashion.

For this reason, looking at the results of a chemical analysis to determine whether or not a product will work isn't as straightforward as for synthetic medicines like aspirin tablets, say, where a certain active ingredient can be identified and measured.

However, there's a need to ensure that the final preparation remains consistent over time, and companies standardise the extract (the SJW source material) against levels of hypericin to determine this consistency. While more isn't necessarily better in terms of effectiveness, unusually low levels indicate quality problems.

We thought it would be interesting to test some widely available SJW tablets to find out whether the products really contained the level of total hypericins stated on the label.

We used the most accurate test procedure available, called high-performance liquid chromatography (HPLC). However, it only gives the figures for hypericin and pseudohypericin. That means the figures we got weren't directly comparable with the labelled claims for total hypericins.

It's been reported that when added together, hypericin and pseudohypericin typically amount to around 60-80% of the known 'total hypericins'. The levels of hypericin and pseudohypericin per tablet that we found averaged 63% of claimed total hypercin. This is in line with what we'd expect, and none of the products tested had startlingly low levels of hypericin.

We also tried to test the tablets using the same method as manufacturers use to obtain figures for total hypericin (spectrophotometric analysis). However, the results were inconsistent, most likely because we were testing on the tablet form, which contains many ingredients, some of which may interfere with analysis. To do this sort of testing accurately would require the co-operation of the companies, so we'd know all the ingredients in the tablets (active and inactive).

So while the results using the HPLC method tend to confirm manufacturers' claims and quality assurance procedures, the fact that it doesn't match the methods they use when making their products doesn't make it at all easy to check their claims. Our experiences highlight the need for a testing procedure that allows for post-market surveillance of quality by independent bodies such as ourselves, to make sure we're getting what we think we're getting when we buy these products.

The lack of transparency we encountered would be unacceptable from manufacturers of conventional medicines. Even in this industry, though, there have been well publicised cases of pharmaceutical companies deliberately withholding research findings from public scrutiny - and, indeed, from licensing authorities - leading to actual or potential serious health problems for people taking the drugs. Fortunately, these cases appear to be uncommon, and when discovered can result in a financially devastating backlash.

Unlike many other complementary healthcare products, there's good evidence for the effectiveness of St John's wort as a treatment for mild depression. When we started this story we thought we'd be able to present you with a thorough assessment of the products on the market and make clear recommendations as to which ones are the best. Due to the constraints on testing the contents of SJW products and the lack of transparency about evidence for their products' efficacy shown by some manufacturers, all we can now say is that the evidence for the claims made by the six brands of SJW (see Evaluating the evidence) is convincing. What we can't tell you is whether any or all SJW products contain what the labels say they do.

If herbal medicines are going to be taken seriously in the general and medical communities, it would be in the interests of consumers as well as those sponsors that make or distribute genuinely effective products if the guidelines for evidence were clearer, tougher and more rigorously enforced. Then the public could be sure that the TGA is regulating effectively, and that the complementary medicine products they're buying are worth the money.

In the final stages of putting this article together, the government announced an overhaul of the regulatory regime for complementary medicines, to take effect at an unspecified time in the future, including a crackdown on the claims being made. Sponsors will then be required to provide the TGA with a summary of evidence, and the TGA will increase its monitoring of the evidence.

At present, though, as a consumer you'd be mistaken if you thought you could buy any formulation of SJW at random and be assured that it works, and that the company has clear evidence that it works. The regulatory system is failing to adequately protect consumers, and also failing to protect those members of the industry who are doing the right thing. In the case of SJW, where there's good evidence of its effectiveness as a treatment for mild depression, this is a real shame.

05.Depression in Australia


It's been said that in any one month 4% of Australians are suffering from depression, and one in five will suffer depression in their lifetime. It's estimated to cost the community $3 billion per year in direct and indirect costs.

Rates of reported depression are on the increase, partly because people are becoming increasingly aware of depression symptoms and coming forward for treatment rather than suffering alone, but also because we (the human race) seem to be getting more and more depressed.

Yet there's concern that despite a big increase in reported levels of depression, it's still underdiagnosed, and it's predicted that it will be the second-largest burden of disease in Australia by the year 2020. Already it's the second most common chronic problem for which people visit a GP, with GPs prescribing around 80-90% of all antidepressants.

What is 'mild' depression?

The official definition of mild depression is having suffered at least two weeks of abnormal sadness or low mood, and being less interested in doing things you previously enjoyed, as well as at least one of the following symptoms: loss of confidence, feelings of excessive guilt, thoughts of death, poor concentration, agitation or retardation (mental and physical slowness), sleep disturbances or change in appetite.

Unlike with more severe forms of depression, people with mild depression can still continue to function at work and home and take part in social activities, but not as well as usual and with less motivation.

Mild depression is usually under-reported because people don't think the symptoms are bad enough to get help, which is unfortunate because diagnosing and treating depression at this early stage can help prevent it becoming worse.

Are we overmedicating?

The use of antidepressants in Australia rose by about 17% per year over the 10 years to 2001, reflecting a worldwide trend. Dramatic increases in depressed patients are bound to put a strain on human medical resources, and prescribing drugs is a time- and cost-effective way of dealing with those who seek treatment. Aggressive marketing by the drug companies may also have increased prescription rates.

But it's not always a good solution. For a start, there's not a lot of evidence the drugs are effective for people with mild depression, although they can be for some. It also reinforces the 'pill for every ill' mentality. Some experts are concerned that prescribing drugs may simply mask psycho-social problems that could be dealt with more effectively by counselling or talking therapies, like cognitive behaviour therapy (CBT). Curing the symptoms won't necessarily cure the illness or provide a long-term solution.

Dependence and withdrawal symptoms are also not unknown, meaning some people are using drugs for long periods of time. And there are many concerns about long-term effects and side effects of newer antidepressants, and even doubts as to how well they work. It's increasingly being recommended that drugs aren't prescribed as a first-line treatment of mild depression.

The preferred treatment for people with mild depression is often counselling or psychological therapy, such as CBT, and many do receive this treatment. Some GPs have been undergoing special training for managing depression, including treatment using focused psychological therapies. Other non-drug management strategies – exercise and 'bibliotherapy' (relevant self-help books) – have also been found useful.

The internet can also be a useful source of treatment, and a study looking at two Australian National University sites – BluePages (designed to educate people about depression) and MoodGym (an interactive website offering information about CBT) – found that they were helpful at reducing symptoms of depression.

More information

The Royal Australian College of General Practitioners recommends the following websites about depression: (aimed particularly at youth)