Numerous RCTs have investigated the effects of valerian as a treatment for insomnia. Although not all results are positive, results from several well conducted placebo-controlled studies suggest that valerian decreases sleep latency and increases sleep quality in poor sleepers. Preliminary evidence suggests that ongoing use may be more effective than single dose use and effects on sleep progress over several weeks.
A number of different valerian products have been studied (e.g. Baldosedron, Baldrien-Dispert, Euvegal, Harmonicum Much, Seda-Kneipp, Sedonium, Valdispert, Valverde and Valerina Nutt). The LI 156 valerian extract is one of the most studied.
A systematic review by Stevinson and Ernst (2000) identified 19 studies involving valerian treatment that were published prior to May 1999. Of these, nine were chosen for inclusion because they were randomised, measured sleep parameters and tested single ingredient valerian products. Three studies considered the cumulative effects of long-term use of valerian whereas six investigated the effects of single-dose treatment. Two of the three studies investigating repeated administration of valerian found that effects were established by 2 weeks. The most rigorous placebo-controlled study showed that valerian LI 156 (600 mg) produced improvement on nearly all measures between weeks 2 and 4. The 4-week study involved 121 volunteers and assessed clinical effectiveness using four validated rating scales. At the end of the study, valerian was rated better than placebo on the Clinical Global Impression Scale, and at conclusion of the study (day 28) 66% of patients rated valerian effective, compared to 26% with placebo. Of the six studies investigating acute effects, valerian produced positive results in three whereas in the other three it was no better than placebo.
Interpretation of study results is difficult because of varying research methodologies. For example, some studies used surveys whereas others used EEG readings, some were conducted at home and others off site in hospitals or sleep laboratories, and pre-bedtime variables (e.g. caffeine consumption) were not fully controlled. Additionally, some studies used healthy volunteers with no sleep disturbances with little scope to observe further improvements. Since then, several other studies have been published.
Donath et al reported positive effects on sleep structure and sleep perception in subjects with insomnia after taking valerian for 14 days under double-blind crossover conditions, whereas single doses of valerian had no effect on sleep structure or subjective sleep assessment.
More recently, a placebo-controlled, three-way crossover study using standardised sleep EEG and psychometric tests evaluated the clinical efficacy of a valerian preparation (LI 156). The 16 adults with sleep disturbances had a mean age of 56 years. Participants slept overnight in a sleep laboratory, following a dose of valerian 300 or 600 mg, or placebo at 9 pm and test periods were separated by 6 days of washout. Results showed no significant effect between valerian 300 and 600 mg or placebo on any EEG parameter or psychometric measure.
In Queensland, a series of n = 1 tests were carried out to investigate the effectiveness of valerian versus placebo for the management of chronic insomnia in general practice. Of the 24 volunteers who had sufficient data for inclusion in the n-of-1 analysis, the response to valerian was poor or modest for all 24 (100%) for ‘total sleep time’ and for 23 (96%) for ‘number of night awakenings’ and ‘morning refreshment’. Valerian was not shown to be appreciably better than placebo in promoting sleep or sleep-related factors for any individual patient or for all patients as a group. Each valerian tablet contained 225 mg V. officinalis root and rhizome extract equivalent to 1000 mg dry root and rhizome (Mediherb, Warwick, Australia; contents standardised to 2.94 mg total valerenic acids, 0.46 mg Valerenal and 1.23 mg Valtrates). Tablets were dispensed as per approved dosage recommendations: two tablets at night taken 30 minutes before bed.
Comparisons with benzodiazepines
Two randomised studies have compared valerian with benzodiazepine drugs. One double-blind trial found that subjects treated with either 600 mg valerian or 10 mg oxazepam experienced significantly improved sleep, with no statistically significant differences detected between the treatments. Another study comparing the immediate sedative effects and residual effects of a valerian and hops preparation, a sole valerian preparation, flunitrazepam and placebo found that subjective perceptions of sleep quality were improved in all treatment groups; however, only flunitrazepam treatment impaired performance the morning after as assessed both objectively and subjectively. Furthermore, 50% of subjects receiving flunitrazepam reported mild side-effects compared with only 10% from the other groups.
A 2002 double-blind randomised trial compared the effects of valerian extract LI 156 (Sedonium) 600 mg/day to 10 mg oxazepam over 6 weeks in 202 patients with non-organic insomnia. The multicentre trial took place at 24 study centres in Germany and found that valerian treatment was at least as efficacious as oxazepam, with both treatments improving sleep quality. Subjectively, 83% of patients receiving valerian rated it as ‘very good’ compared with 73% receiving oxazepam.
The efficacy and tolerability of a valerian and lemon balm combination (Euvegal® forte) was tested in a large, open, multicentre study of 918 children (aged under 12 years) with restlessness and nervous sleep disturbance (dyssomnia ). Both investigators and parent’s ratings revealed a reduction in the severity of symptoms for most patients. The study reported that 81 % of children with dyssomnia experienced an improvement and 70% of children with restlessness improved. Treatment was generally rated as good or very good and considered well tolerated. Each Euvegal® forte tablet consisted of 160 mg valerian root dry extract (Valeriana officinalis L.) with a drug-extract ratio of 4-5:1 (extraction solvent ethanol 62% v/v) and 80 mg lemon balm leaf dry extract (Melissa officinalis) with a drug-extract ratio of 4-6:1 (extraction solvent ethanol 30% v/v). The standard dosage of Euvegal® forte (4 tablets daily) was used by 75% of patients and chosen by the investigator.
ANXIETY AND PSYCHOLOGICAL STRESS STATES
Less investigation has taken place to determine the role of valerian as a treatment for anxiety states. The few studies published thus far have produced encouraging results, but are hampered by methodological problems and well conducted trials are still required.
A randomised study found that low-dose valerian (100 mg) reduced situational anxiety without causing sedation. Positive results were also obtained in a smaller open study of 24 patients suffering from stress-induced insomnia who found treatment (valerian 600 mg/day for 6 weeks) significantly reduced symptoms of stress and insomnia. Another randomised trial compared the effects of a preparation of valepotriates (mean daily dose 81.3 mg) with diazepam (mean daily dose 6.5 mg) and placebo in 36 outpatients with GAD under double-blind conditions. After 4 weeks’ treatment, all groups had significant reductions in Hamilton anxiety (HAM-A) scale scores; however, only those receiving valepotriates or diazepam showed a significant reduction in the psychic factor of HAM-A.
Kava kava is a herbal medicine also used in the treatment of anxiety and found to be effective in clinical studies. A study that compared the effects of kava kava to valerian and placebo in a standardised mental stress test found that both herbal treatments reduced systolic blood pressure, prevented a stress-induced rise in heart rate and decreased self-reported feelings of stress.
MUSCLE SPASM AND CRAMPING
Valerian preparations have long been used to treat a wide variety of gastrointestinal disorders associated with spasms such as diarrhoea, colic and irritable bowel. It has also been used to relieve cramping in dysmenorrhoea. Although no controlled studies are available to confirm clinical effectiveness in these conditions, valerian is likely to exert some degree of antispasmodic activity based on its pharmacological actions.
Valerian: Other Uses
One randomised study, which was investigator blinded, tested the effects of whirl baths with plain water or with water containing pine oil or valerian on pain, disturbed sleep and tender point count in 30 outpatients with generalised fibromyalgia. Valerian significantly improved wellbeing and sleep together with decreasing tender point count, whereas baths with pine oil worsened pain and plain water baths reduced pain but had no effect on wellbeing and sleeplessness.
Although no clinical studies are available, the herb is also used in practice to reduce dependency on benzodiazepine drugs. Valerian is prescribed together with other herbal medicines and psychological counselling while the benzodiazepine dose is slowly reduced.
Valerian: Dosage Range
• Infusion of dried root: 3-9 g/day.
• Liquid extract (1:2): 2-6 mL/day.
• Tincture (1:5): 5-15 mL/day.
• When used for insomnia, valerian should be taken approximately 1 hour prior to bedtime.
ACCORDING TO CLINICAL STUDIES
• Anxiety: 100 mg-600 mg/day of the dried root or valepotriates (mean daily dose 81.3 mg).
• Insomnia: doses above 600 mg/day taken 1 hour before bedtime.