Valerian: benefits, dosage, contraindications

Mis à jour le

Valerian is a perennial herbaceous plant measuring 1 to 1.5 meters in height. Native to Europe and Asia and acclimatized in the northeastern part of North America, valerian prefers clay-siliceous soils. It is found in shady, moist locations. Valerian has been used since antiquity for various properties, notably for its sedative virtues. This property is the origin of its name: valeriana comes from the Latin valere, which means 'to be well'. The roots are the parts used therapeutically. The pharmacological effects of valerian have been mainly attributed to valepotriates (iridoid esters such as valtrate), essential oils, monoterpenes and sesquiterpene constituents. The primary monoterpene is borneol and the primary sesquiterpenes are valerenic acid and valeranone. Other potentially active constituents include the flavonoids 6-methylapigenin, hesperidin and linarin. Valepotriates break down into other potentially active compounds, notably baldrinal and homobaldrinal. The characteristic unpleasant odor of valerian has been attributed to isovaleric acid. Valerian is widely used for sleep disorders, notably insomnia, but also for anxiety and stress.

Other name(s) 

Valerian of the hills, small-leaved valerian, St. George's herb

Scientific name(s)

Valeriana officinalis

Family or group: 

Plants

Active ingredients:

Flavonoids

valepotriates

Glutamine

GABA

Valerenic acid

Valtrate


Indications

Scoring methodology

EFSA approval.

Several randomized, double-blind, controlled clinical trials (> 2), including a significant number of patients (>100), with consistently positive conclusions for the indication.
Several randomized, double-blind, controlled clinical trials (> 2), including a significant number of patients (>100), with positive conclusions for the indication.
One or more randomized studies, or several cohorts or epidemiological studies, with positive conclusions for the indication.
Clinical studies exist but are uncontrolled, with conclusions that may be positive or conflicting.
No clinical studies to date that can demonstrate the indication.


Sleep disorders
✪✪✪✪

Most research shows that oral intake of valerian modestly reduces the time to fall asleep and improves subjective sleep quality. nnThe greatest benefit is generally observed in patients who take 400 - 900 mg of valerian extract up to 2 hours before bedtime. nnMeta-analyses show that taking valerian significantly increases the chances of having improved sleep quality by 37% to 80% compared with placebo.nn

Posologie

posologieOral: root

posologie400 - 900 mg

formulationdry extract


Synergies


Menopause
✪✪✪✪✪

Some clinical research shows that taking 225 mg of ground valerian root three times a day for 8 weeks reduces the severity of hot flashes by 47% and their frequency by 39% compared with baseline in menopausal women. Other clinical research shows that taking a valerian root extract at 530 mg twice a day for two months reduces the severity of hot flashes in 80% of patients and reduces the frequency of hot flashes by 49% compared with baseline in menopausal women. In both studies, these improvements were significant compared with placebo treatment, which did not improve these outcomes.

Posologie

posologieOral: root

posologie675 - 1060 mg

duration8 - weeks

formulationdry extract


Anxiety
✪✪✪✪✪

There is conflicting evidence on the effectiveness of valerian for anxiety. A preliminary study shows that taking 100 mg of valerian three times a day for 21 days reduces anxiety in patients with mild anxiety. Preliminary clinical research has also reported that taking 1 to 2 capsules of 50 mg valerian root and 100 mg St. John's wort twice a day for 2 weeks improves symptoms of moderately severe anxiety more effectively than diazepam 2 mg twice a day. However, other preliminary research seems to suggest that valerian extract standardized to valepotriates or valerenic acid has no beneficial effect on generalized anxiety disorder. These inconsistencies may be due to the doses or to the concentration of valepotriates or valerenic acids contained in the valerian preparation.

Posologie

posologieOrally: root

posologie100 - 300 mg

duration21 - days

formulationdry extract


Synergies


Stress
✪✪✪✪✪

Preliminary research suggests that taking 600 mg of valerian for 7 days before participating in a mental stress session significantly attenuates the corresponding increases in systolic blood pressure, heart rate, or feeling of pressure. nnOther research suggests that taking 100 mg of valerian before a verbal test in front of an audience reduces subjective feelings of anxiety compared with placebo. However, this study was not able to determine whether the difference between groups was statistically significant.nn

Posologie

posologieOral: root

posologie100 - 600 mg

formulationdry extract


Nervousness
✪✪✪✪✪

The EMA recognizes as established the efficacy of valerian in relieving mild nervous tension and sleep disturbances.nn

Posologie

posologieOral: root

posologie576 - 1350 mg

formulationdry extract


Dysmenorrhea
✪✪✪✪✪

Preliminary clinical research suggests that taking 255 mg of powdered valerian root three times a day for two menstrual cycles significantly reduces the duration of severe menstrual pain and the need to use additional analgesics.nn

Posologie

posologieOral: root

posologie765 mg

formulationdry extract


Properties


Sedative

full-leaffull-leaffull-leaffull-leaf

Valerenic acid and its derivatives produce a mild sedative effect when administered orally to animals. The sedative and hypnotic action is gradual (the effect may appear only after 14 days) and is thought to be enhanced by a lignan (hydroxypinoresinol), which binds to benzodiazepine receptors and may act synergistically with valerenic acid and valepotriates.nnTwo flavonoids, hesperidin and linarin, would also contribute to valerian's sedative and hypnotic effects, acting synergistically with 6-methylapigenin and valerenic acid.nnSeveral clinical trials have shown that valerian improves sleep quality and reduces the time to fall asleep.nn

Usages associés

Sleep disorders, nervousness

Anxiolytic

full-leaffull-leaffull-leafempty-leaf

The anxiolytic, anticonvulsant, and sedative effects of valerian are likely due to the action of its constituents on several receptors, notably those for gamma-aminobutyric acid (GABA), adenosine A1, and serotonin (5-HT1). Valerenic acid, one of its components, acts as a GABA agonist.nnValerian may increase GABA concentrations, thereby reducing central nervous system activity, and bind to GABA-A receptors. It could also influence sleep regulation via adenosine and serotonin receptors.nnStudies suggest that valerian may also have antidepressant effects, possibly related to GABAergic mechanisms or binding to serotonin receptors (5-HT1A).nn

Usages associés

Anxiety, Sleep disorders, Stress, Nervousness

Antispasmodic

full-leaffull-leafempty-leafempty-leaf

This antispasmodic action is due primarily to valepotriates. These compounds act on centers of the central nervous system and cause relaxation of smooth muscle by modulating calcium entry into cells or by binding directly to smooth muscle.nn

Usages associés

Dysmenorrhea


Safe dosage

Adults aged 12 years and older: 400 mg - 600 mg

- Single dose: 400-600 mg of dry extract for the relief of mild nervous tension up to 3 times per day. - Dry extract (DER 4-6:1), extraction solvent: water, single dose of 420 mg for the relief of mild symptoms of mental stress up to 3 times per day. - Dry extract (DER 4-7:1), extraction solvent: methanol 45% (V/V), single dose of 144-288 mg for the relief of mild symptoms of mental stress up to 4 times per day. To promote sleep, a single dose 1 hour before bedtime, with an additional dose earlier in the evening if necessary. - Dry extract (DER 5.3-6.6:1), extraction solvent: methanol 45% (m/m), single dose of 450 mg for the relief of mild symptoms of mental stress up to 3 times per day. To promote sleep, a single dose 1 hour before bedtime, with an additional dose earlier in the evening if necessary.


Interactions

Médicaments

Benzodiazepines: moderate interaction

Theoretically, concomitant use with benzodiazepines can lead to additive therapeutic and adverse effects. Some benzodiazepines include alprazolam (Xanax), clonazepam (Klonopin), diazepam (Valium), lorazepam (Ativan), midazolam (Versed), temazepam (Restoril), triazolam (Halcion), and others.

Alprazolam: moderate interaction

Taking a valerian extract at 1000 mg per day (providing 10 mg of valerenic acid) appears to increase alprazolam levels by about 19%. This is most likely due to valerian's inhibitory effects on cytochrome P450 3A4 (CYP3A4) (13014). Although this increase is statistically significant, it may not be clinically significant.

Cytochrome P450 3A4: moderate interaction

There is in vitro evidence that valerian may increase the metabolism of testosterone, a substrate of the cytochrome P450 3A4 (CYP3A4) enzyme, in human hepatocytes. However, other in vitro evidence shows that valerian inhibits the CYP3A4-mediated metabolism of dibenzylfluorescein and 7‑benzyloxyresorufin in solution. Clinical research suggests that valerian does not significantly inhibit CYP3A4 at relatively low doses of 375 mg per day, but has modest effects at higher doses of 1000 mg per day. Drugs metabolized by CYP3A4 include lovastatin, ketoconazole, itraconazole, fexofenadine, triazolam, chemotherapeutic agents, and many others. Use valerian with caution or avoid it in patients taking these medications

Plantes ou autres actifs

Sedative: minor interaction

Using valerian with other herbs and supplements that have sedative properties may increase both therapeutic and unwanted effects. These products include calamus, California poppy, catnip, hops, kava, L-tryptophan, melatonin, sage, SAMe, St. John's wort, and others.


Precautions

Children up to 12 years: avoid

Insufficient data.

Pregnant women: avoid

Safety during pregnancy and breastfeeding has not been established. In the absence of sufficient data, use during pregnancy and breastfeeding is not recommended.

Breastfeeding women: avoid

Safety during pregnancy and breastfeeding has not been established. In the absence of sufficient data, use during pregnancy and breastfeeding is not recommended.

Surgery: avoid

Valerian has depressant effects on the central nervous system (CNS). Valerian could cause additive CNS depression when combined with anesthesia and other medications during and after surgery. It is advised to stop taking valerian at least two weeks before non-urgent surgical procedures.