Valerian Root (Valeriana officinalis)

Indications

Insomnia and possibly nervousness and anxiety.

Mechanism of Action

Several constituents of Valeriana officinalis have been found to have sedative or anxiolytic properties. These constituents are valerenic acid (VA), 6-methylapigenin (MA), (2S)-hesperidin (HN), and the flavonoid glycoside linarin (LN). VA and MA have been shown to have GABAergic activity. The mechanism by which LN and HN has a sedative effect is still unknown, but it does not seem to be via GABAergic pathways.

When administered simultaneously, LN and VA have been shown to act synergistically,¹ as have MA and HN.² The sedative and soporific effects of Valeriana officinalis therefore can likely be attributed to the activity of at least the four constituents LN, HN, MA, and VA plus their potentiating effects when the whole root is used.¹

Valerian root extract contains over 150 chemical constituents including alkaloids, flavones, organic acids and their derivatives, terpenes, and valepotriates.

6-methylapigenin, a component of valerian, is a positive GABA_A modulator, proposedly binding to α and γ subunits at the benzodiazepine site. Valerenic acid and valerenol, components of valerian, interact with the β subunit of the receptor of GABA.

Valerian extract directly interacts with serotonin receptors, which is one of the neurotransmitters regulating wakefulness.³

Evidenced-Based Research

A review of studies has demonstrated valerian’s ability to reduce various types of anxiety and stress, promote calm, and improve sleep quality.

A prospective, triple-blinded, randomized, placebo-controlled, parallel design study of 37 participants demonstrated improvement in sleep quality and a reduction in the severity of Restless Leg Syndrome (RLS).

In a study of 20 volunteers undergoing a third molar surgery, a single dose of valerian prior to surgery exhibited a greater anti-anxiety effect than placebo.

A randomized, double-blinded, placebo-controlled trial was conducted that was comprised of 61 patients aged 30 to 70 years undergoing coronary artery bypass graft surgery using cardiopulmonary bypass. Valerian given every 12 hours, 1 day before surgery and continued 60 days after surgery, demonstrated decreased odds of cognitive dysfunction, for which the study may have been related to better sleep quality.

In a pilot randomized, double-blinded, placebo-controlled, clinical trial with 51 patients who were HIV-positive, valerian given every night before going to sleep improved anxiety and sleep.

A double-blind and randomized eight-week trial comprised of 31 patients with obsessive-compulsive disorder (OCD) taking valerian demonstrated that the herb had some anti-obsessive and compulsive effects.⁴

Safety in Pregnancy and Breastfeeding

In two studies of pregnant rats, very high doses of V. officinalis were administered for 7 days during the gestational period. One study used doses up to 2.7 g/kg, which is 65 times higher than the normal human dose. This study found no signs of maternal toxicity, and no observable adverse effects on fetal development.⁵ The second study, which used doses of 2.8 g/kg, found a reduction in placental weight, but not in birth weight.⁶

No concern is noted in traditional use for nursing mothers using V. officinalis.⁷ However, no evidence base currently exists regarding its use during lactation.

General Safety

A meta-analysis of 16 randomized, placebo controlled trials (totaling 1093 patients) demonstrated a high degree of safety with oral administration of V. officinalis root. With the exception of a single study, adverse events were either not observed or were similar to placebo. The exception was a study where the treatment group had a significant increase in diarrhea compared with controls.⁸

Idiosyncratic, stimulant-like reactions have been reported anecdotally. One source estimates that 2%–3% of the population is susceptible to stimulant-like effects such as increased heart rate and agitation.⁹

In addition to the meta-analysis, one patient experienced a movement disorder after combining the herbs valerian and passionflower with lorazepam for generalized anxiety disorder.  There are additive effects between these substances.^9b

Dosage

Most studies of safety and efficacy use a time frame of up to 30 days and a dose of 400–900 mg around 2 hours before bedtime. Taking 300–450 mg daily of a V. officinalis extract in three divided doses has also been shown to be safe and effective.¹⁰

Traditional Uses

Valeriana officinalis is native to Europe and western Asia; it was introduced into the United States and Canada. The genus name comes from the Latin valere, which means to be strong and healthy.¹¹ The ancient Greek used it to treat insomnia, among other conditions.¹²