Herbal Remedies and sleep


Why try herbs to help your sleep?
About 40% of people use alternative or complementary medicines at least occasionally. This can be for many reasons, including problems with sleep. Some people who are concerned about using sleeping pills will turn to herbal remedies to help them sleep (see our page on Sleeping Tablets). Melatonin is not a herbal remedy (for more information see Melatonin).
Has the effectiveness of herbs in treating sleep problems been adequately studied?
Studies of the effectiveness of herbs for sleep problems have not always been as thorough as they should have been. Sometimes it seems that the treatment works well, however with any new treatment it is important to check that this effect is not simply a placebo (or dummy) effect that could have occurred if a sugar pill had been taken. Many studies of herbal remedies have failed to properly compare outcomes with those from a placebo treatment.
For some herbal remedies disappointingly few studies have been done. One reason for this is that herbs cannot be patented, only an active chemical ingredient of the herb. Trials testing effectiveness are expensive and, without a patent, companies may not be able to recover their costs through guaranteed sales, even if the herb has potential.
However there have been studies of some of the herbs used for insomnia and anxiety. Here we focus on herbs where reasonable information exists from clinical research trials. We only examine herbs that have been studied as a single product, rather than blended with other substances.
What does the evidence say about herbs helping sleep?
In the table below, we look at the effectiveness of nine herbs in the treatment of insomnia. The order in which they are listed is based on the strength of the evidence that they are effective (strongest first). The first column shows whether the herb has been found to work in a trial in humans, comparing the herb to a placebo. This is the best type of study to see if it helps or not. The second column shows whether there are other (animal or laboratory) research findings that the herb helps insomnia, but this evidence is not as strong as evidence from a human trial. The third column shows the strength of results across all the trials for insomnia. There are three possible levels of evidence that can be found. If well-run studies have found consistently good results, the level is High. If the results are mixed but mainly good, the level is Medium. If there is a mix of both good and poor results, the level is Low.
If we look at the first column of the Table we can see that of the nine herbs listed, the first four have been shown to help with insomnia in some human clinical trials. These are Kava, Valerian, Passionflower and Hops. Three of these also have some support from animal or laboratory studies. The third column summarises the evidence and the findings suggests that, on the whole, the supporting evidence for treatment of insomnia with these herbs is Low. In many cases a conclusion has not been reached because insufficient quality research has been done to make a judgment about their role. The overall conclusion is that the evidence for any of these herbs helping with insomnia is fairly weak.

Herbal Medicine Some support via human clinical trials? Some support via animal or test tube studies? Evidence level for helping insomnia
Kava (Piper methysticum)  Yes Yes More research needed
Valerian (Valeriana spp.) Yes Yes Low
Passionflower (Passiflora spp) Yes No Low
Hops (Humulus lupulus) Yes Yes More research needed
Sour date (Zizyphus jujube) No Yes More research needed
Mimosa (Albizia julibrissin) No Yes Low
Lavender (Lavendula spp.) No  Yes  More research needed
California Poppy (Eschscholzia californica) No Yes More research needed
Chamomile (Matricaria recutita) No No More research needed

What about these herbs and anxiety?

We know that some people have difficulty sleeping due to anxiety (see Anxiety and Sleep). Clinical trials in humans has shown that three herbs perform reasonably well in reducing anxiety These are Kava, Passionflower and Chamomile. It was concluded that Kava had a High evidence level for its anxiety reducing effects, while Passionflower and Chamomile had Medium evidence levels.

What kind of things may affect the results of a study?
Not all researchers use the same methods to select people for their studies and they might not assess all types of insomnia. It is possible that herbal remedies may be more effective for some types of insomnia than others but more research is needed to confirm this. As well as this, we can’t be sure that all of the studies used the same strengths of extracts from the herb.

Can I expect herbal cures to work straight away?
Most studies look at the effect of the herbs over a number of weeks. Hence it is best to not expect results after one or two nights. Valerian, in particular, is known to take time to start to work. Thus, if it is going to help sleep at all, it tends to take two or three weeks before there is an improvement.

Are the herbal remedies safe to use?
There have been some worries about the safety of Kava. A 2002 review of its safety found that Kava extracts seem to be safe for most users. However this is only when taken in the short term and at doses that are not too high. Unfortunately, some Kava users have been found to suffer serious side effects, e.g. liver problems. More research needs to be done on this. Also, studies have found that it might not be safe to take Kava together with benzodiazepines (the type of drug in many sleeping tablets).

Main Reference Source:
J. Sarris, A. Panossian, I. Schweitzer, C. Stough, A. Scholey (2011) Herbal medicine for depression, anxiety and insomnia: A review of psychopharmacology and clinical evidence. European Neuropsychopharmacology, Volume 21, Issue 12, December 2011, Pages 841–860.

Additional Reference Sources:
D. Wheatley (2005) Medicinal plants for insomnia: a review of their pharmacology, efficacy and tolerability. J Psychopharmacol, Volume 19, Pages 414-421.
C. Stevinson, A. Huntley, Ernst E. (2002) A Systematic Review of the Safety of Kava Extract in the Treatment of Anxiety. Drug Safety, Volume 25, Number 4, Pages 251-261.

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Where can I find out more?