Valerian can be taken daily for a limited period, if the specific medication's instructions direct and the individual tolerates it well. However, daily use for months or years cannot be considered proven safe: there is insufficient high-quality data on long-term, continuous use.
Valerian does not necessarily require a course of treatment in all cases. Some dosage forms require a single dose before bedtime, but the European Medicines Agency notes that the effect of a certain standardized dry extract develops gradually, and continuous use for 2-4 weeks is recommended for optimal results.
If using a valerian supplement to help induce sleep, a good rule of thumb is to take it approximately 30-60 minutes before your intended bedtime, if that's what the specific product's instructions say.
It's impossible to say for sure whether valerian "starts working in 20, 30, or 60 minutes." The European Medicines Agency recommends taking some valerian root preparations for sleep approximately 30-60 minutes before bedtime, but this is a time of administration, not a proven time for the onset of sedative effects.
Valerian may have a calming effect and has been shown to reduce anxiety symptoms in some studies, but there is insufficient evidence to consider it an effective treatment for anxiety disorder.
There is currently no convincing evidence that valerian reduces the frequency of night awakenings or helps people fall back to sleep more quickly after awakening. Night awakenings are considered a sleep-maintenance disorder, or sleep-maintenance insomnia.
Valerian may improve the subjective experience of sleep quality in some people, but evidence for this effect remains mixed, and convincing and reproducible improvements in objective sleep parameters—time to fall asleep, sleep duration, number of nocturnal awakenings, or sleep efficiency—have not yet been established.
Valerian may subjectively improve sleep in some people, but there is no convincing evidence that it reliably treats insomnia, shortens the time it takes to fall asleep, or increases sleep duration.
