Is it necessary to take valerian in a course and for how many days?

Valerian does not necessarily need to be taken as a course 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 for optimal results, continuous use for 2-4 weeks is recommended. This applies to the specific category of medicinal extract, and not to all valerian tablets, tinctures, teas, and dietary supplements. [1]

However, the recommendation to "take valerian for 2-4 weeks" cannot be interpreted as proof that it necessarily begins to work after it accumulates in the body. A pharmacokinetic study found no significant accumulation of valerenic acid after two weeks of regular use. And sleep studies yield conflicting results: in one small trial, some sleep parameters improved after 14 days, although not after the first dose, while in another, neither a single dose nor two weeks of treatment yielded any advantage over placebo. [2]

The main practical limitation is even more significant: modern systematic evaluations do not support the reliable efficacy of valerian for chronic insomnia. A 2024 umbrella review found no convincing evidence of its effectiveness, and the 2023 European Insomnia Guidelines and the 2025 VA/DoD Guidelines do not recommend valerian as a treatment for chronic insomnia. Therefore, course treatment should be considered only within the guidelines for a specific drug and for limited symptomatic use, and not as a mandatory treatment for any insomnia or anxiety. [3]

Why was there a recommendation to take valerian for several weeks?

For some valerian preparations, the European monograph distinguishes between a single dose regimen and the duration of treatment.

For sleep disorders, a specific dry extract is taken approximately 30-60 minutes before bedtime; if necessary, the instructions allow for an additional dose earlier in the evening. However, in the section on duration of use, the EMA specifically states that due to the gradual onset of effectiveness, valerian is not suitable for rapid intervention for mild nervous tension or sleep disorders, and the optimal effect is expected with continued treatment for 2-4 weeks. [4]

This is where the expression “valerian should be taken in a course” originated in popular literature.

But the monograph contains an important detail that is often overlooked: the 2-4-week regimen is given for well-established medicinal use of a specific dry ethanol extract. The same monograph lists numerous other forms—ground root, tea, water and alcohol extracts, tinctures. For traditional forms, a fixed, mandatory course of 2-4 weeks is not established in the same way; if symptoms persist, it is recommended to consult a medical specialist. [5]

Therefore, the statement “any valerian must be taken for 2-4 weeks” is too broad.

What does "gradually effective" mean?

The EMA's phrase about gradual onset of efficacy does not mean that valerian must necessarily physically accumulate in the blood to a certain concentration.

This difference can be verified experimentally. In a pharmacokinetic study in elderly women, valerenic acid was measured after a single dose of valerian and after two weeks of regular evening use. The researchers found no statistically significant differences in the maximum concentration of the substance, the time to reach maximum, the area under the pharmacokinetic curve, half-life, or clearance. [6]

In other words, a simple scheme:

Day 1 → little substance → Day 14 → valerian accumulated → effect appeared

Not supported by these pharmacokinetic data.

If gradual clinical effects do occur with some drugs, they may be related to more complex pharmacodynamic mechanisms, changes in sleep perception, natural fluctuations in symptoms, or other factors. Current research does not yet provide a definitive explanation.

Are there any studies where a course of treatment was more effective than a single dose?

Yes, such a small study exists, but its results are not sufficient for a general rule.

A 2000 randomized, double-blind, crossover study involved 16 patients with psychophysiological insomnia. Researchers compared a single dose of valerian extract with regular use for 14 days, assessing sleep using polysomnography and subjective questionnaires. [7]

After a single dose, no significant effect on sleep structure or subjective sleep assessment was observed. After 14 days, some slow-wave sleep parameters changed in favor of valerian: the time until the onset of slow-wave sleep decreased, and its proportion relative to baseline increased. A trend toward a reduction in subjective time to fall asleep was also observed. [8]

But the main outcome measure—sleep efficiency—improved relative to baseline with both valerian and placebo. The sample size was very small, and the study was published over two decades ago.

Therefore, it supports the idea that the effects of some drugs may be better after repeated use, but does not prove that a course is necessary for everyone.

Other studies of the course have yielded negative results.

This is crucial because the positive work was not consistently replicated.

In a randomized study, 16 elderly women with insomnia took 300 mg of concentrated valerian extract approximately 30 minutes before bedtime. Researchers assessed sleep after the first dose and after two weeks of daily treatment using polysomnography, actigraphy, sleep diaries, and subjective measures. [9]

After either a single dose or two weeks, valerian did not differ from placebo in sleep onset time, wakefulness after sleep onset, sleep efficiency, or subjective sleep quality. The authors concluded that regular valerian use did not improve insomnia in this sample.[10]

The result is indicative: the mere fact of a two-week course does not guarantee that effectiveness will appear where it was not present after the first dose.

Is there any current positive data on long-term use?

There is a separate, relatively modern study that has produced positive results.

In a randomized, double-blind study published in 2024, 80 adults with sleep complaints received a standardized valerian extract or placebo for eight weeks. In the extract group, some measures, including time to fall asleep using actigraphy, improved as early as the third day; other changes became visible on days 14, 28, and 56. [11]

Polysomnography was performed in some participants; by day 56, improvements in total sleep duration, time to sleep onset, and sleep efficiency were recorded compared with placebo.[12]

This is an interesting argument that a single standardized extract may be effective with regular use. However, this is a single, relatively small study of a specific drug in people with predominantly mild sleep complaints.

Therefore, its result does not change the overall assessment of the evidence: a 2024 umbrella review including eight systematic reviews concluded that there is no convincing evidence for the effectiveness of valerian for insomnia overall. [13]

What do systematic reviews say about coursework?

The main problem with valerian research is not the lack of treatment duration per se, but the heterogeneity of the entire evidence base.

The studies used different dry and liquid extracts, different doses, different treatment periods, and different patient groups. Some participants had diagnosed insomnia, while others only complained of sleep problems. Some studies assessed outcomes using subjective questionnaires, while others used polysomnography or actigraphy. [14]

A 2024 umbrella review found the potential for subjective improvements in sleep quality, but the effectiveness was not convincingly supported by quantitative or objective measures. The authors explicitly characterized the existing literature as heterogeneous and methodologically weak. [15]

This leads to an important conclusion: the problem of conflicting studies cannot be solved by simply recommending “drink for longer.”

Does this mean that a single dose is pointless?

No. Some valerian preparations officially recommend a single evening dose to aid sleep.

The European monograph for various dosage forms recommends taking the medication approximately 30-60 minutes before bedtime. This means that a person can use the medication in the evening without having to wait several weeks before trying it for the first time. [16]

However, the clinical effect of the first dose is unpredictable. In some studies, a single dose of valerian did not change objective sleep parameters. [17]

Therefore, the model “valerian only works in a course, and one tablet does nothing at all” is also overly categorical.

More accurately, a single dose may subjectively help a specific individual, but for some standardized medications, the regulator assumes a better result with regular use; however, clinical studies do not consistently show a benefit from a course of treatment for all patients.

Should I take a course of valerian for insomnia?

For chronic insomnia, there is no reason to consider a course of valerian as the recommended primary treatment.

The 2023 European Insomnia Guidelines do not explicitly recommend herbal remedies for insomnia. The first-line treatment for chronic insomnia is cognitive behavioral therapy for insomnia. [18]

The 2025 VA/DoD guidelines also provide a weak recommendation against the use of valerian for chronic insomnia. The working group rated the quality of the evidence as very low and noted that supplements have not been shown to convincingly improve insomnia outcomes, and their use may delay more proven treatments. [19]

Therefore, a person who has been sleeping poorly for months should not perceive a four-week course of valerian as a mandatory step before seeking help.

And if sleep problems are short-term

The situation here is different.

For occasional sleep problems due to temporary stress, adults can use a registered medication according to its instructions, provided there are no contraindications or significant interactions.

If the particular dosage form is a standardized extract for which the instructions call for regular use, that regimen can be followed.

But one shouldn't expect a mandatory "cumulative effect on day 10 or 14." Clinical trials don't allow one to determine such a universal point.

It is more useful to evaluate whether it has actually become easier to fall asleep, whether night awakenings have decreased, and whether daytime conditions have improved.

Should I take valerian in a course for stress?

There is no convincing evidence base for a course of valerian as a treatment for chronic stress.

EMA allows a certain dry extract for mild nervous tension and specifically for this it describes a gradual development of the effect and continuation of use for 2-4 weeks. [20]

But the NCCIH points out that the available research is not enough to conclude that valerian is effective for stress or anxiety.[21]

A randomized trial of 64 people with psychological stress taking valerian extract for four weeks found some changes in functional brain connectivity, but there were no significant differences between valerian and placebo on clinical stress and anxiety scales.[22]

That is, a month-long course alone does not turn valerian into a proven treatment for chronic emotional stress.

How long does it make sense to try the drug?

For a specific standardized extract, the EMA offers a fairly clear cutoff: optimal effect is expected with continuous use for 2-4 weeks, but if symptoms persist or worsen after two weeks, a doctor should be consulted. [23]

This does not mean that you must continue until the fourth week regardless of the result.

If a drug causes side effects, there is no need to “finish the course” for the sake of mythical accumulation.

If nothing at all has changed after a reasonable period of time, then indefinite continuation is also difficult to justify.

And if the underlying problem itself requires treatment—such as chronic insomnia or severe anxiety—waiting until several consecutive courses of valerian have been completed may simply be delaying more beneficial help.

Can I take valerian daily for a month?

For most adults, short-term use has been studied significantly better than long-term use.

The NCCIH reports that valerian has been used with acceptable safety in studies at doses of 300-600 mg per day for up to six weeks. However, this figure applies to the drugs studied and primarily characterizes short-term safety—it is not a universal treatment regimen. [24]

The long-term safety of valerian remains poorly understood. NCCIH specifically states that there is insufficient data on the safety of long-term use. [25]

Therefore, a monthly course of a particular registered drug may fit within the short-term range studied, but this does not mean that taking valerian for months on end is beneficial for everyone.

Can valerian be taken continuously?

There is no good evidence base for continuous, indefinite use.

First, its long-term effectiveness is unknown. If the drug doesn't produce clinically noticeable results, there's no point in continuing to take it.

Secondly, long-term safety has been studied less well than short-term safety. [26]

Third, rare cases of symptoms have been described following abrupt cessation of long-term regular use of valerian. The NCCIH lists anxiety, irritability, insomnia, cardiac disturbances, and, very rarely, hallucinations; a single published case report describes delirium following discontinuation of long-term use. Such reports do not allow us to quantify the risk, but they demonstrate that "herbal" does not mean "suitable for indefinite use." [27]

Is it necessary to take a break between courses?

There is no scientifically established universal scheme like “drink for a month and then take a two-week break” for valerian.

The EMA does not mandate a cyclical regimen of courses with fixed breaks. NCCIH also does not propose such a scheme. [28]

Therefore, advice such as “be sure to take a break every 20 days” or “the course can only be repeated after a month” should not be presented as evidence-based medical advice.

If a person constantly requires a new course, it is much more important to answer another question: why does the symptom return and does valerian really significantly control it?

If insomnia is recurring, it may be a chronic sleep disorder. If tension is constant, it could be an anxiety disorder, chronic stress, or another cause. In this case, alternating courses doesn't solve the underlying problem.

Is it necessary to gradually discontinue valerian after the usual course?

For standard short-term use, there is no official universal requirement to gradually reduce the dose.

However, the NCCIH notes reports of withdrawal symptoms after chronic use. This applies primarily to long-term regular use and does not support the need for gradual withdrawal after a typical short course. [29]

If a person has been taking high amounts of valerian for months or combining it with other sedatives, it is best to discuss discontinuation individually with a doctor or pharmacist.

This is especially important if benzodiazepines, sleeping pills, or other medications that cannot be stopped abruptly on your own are being used concurrently.

Can a long course of treatment harm the liver?

Clinically significant liver damage has been reported with valerian but is considered very rare.

LiverTox reports only a small number of published cases; in many, other herbal preparations were used concurrently, making it difficult to establish the causative role of valerian. Given its very widespread use, valerian is classified as a rare potential cause of drug-induced liver injury.[30]

In published cases, symptoms usually appeared several weeks after initiation of use, but these observations cannot be used to calculate individual risk or to assert that a course of a given duration is dangerous.[31]

The practical conclusion is simpler: the rarity of complications does not require laboratory monitoring of the liver in every healthy person, but the uncontrolled use of concentrated herbal remedies for many months without clear benefit has no good basis.

A course of valerian and alcohol or other sedatives

The duration of the course does not eliminate the risk of combining several sedative effects.

NCCIH recommends against combining valerian with alcohol and sedatives due to the potential for increased central nervous system depressant effects.[32]

The EMA also states that combination with other sedatives requires medical diagnosis and monitoring.[33]

Therefore, the scheme “a sedative during the day, valerian in the evening, a sleeping pill at night” does not become safe just because each drug is taken in a “course”.

How to evaluate whether a course makes sense in a particular situation

It is more useful to define the goal in advance.

Situation	How to take a course of valerian
Sometimes it's hard to relax before bed.	You can use a specific drug according to the instructions; there is no mandatory course for everyone.
Specific dry extract with EMA regimen	Continuous use for 2-4 weeks corresponds to the monograph
There is no effect after the first dose.	This does not prove ineffectiveness, but you should not increase the dose on your own.
After 1-2 weeks there is no noticeable improvement	Don't wait forever for things to accumulate; you need to reconsider your approach
Chronic insomnia	A course of valerian is not a recommended standard treatment.
Constant stress or severe anxiety	There is insufficient evidence for treatment with valerian.
The drug really helps and is well tolerated.	You can follow a limited course according to the instructions of a specific product.
Refresher courses are required month after month.	The cause of persistent symptoms needs to be assessed.
Alcohol or other sedatives are used	The additive sedative effects must be taken into account.

[34]

Why a "course" doesn't equal a proven cure

This is one of the most important points on the topic of valerian.

In everyday usage, the word "course" sounds like a sign of a complete therapy: if a medication is prescribed for two or four weeks, it seems that the effectiveness of such a regimen has already been proven.

But duration of use and proof of clinical effectiveness are two different issues.

The EMA does recognize a certain dry ethanol extract for the relief of mild nervous tension and sleep disorders and recommends continued use for 2-4 weeks due to its gradual action.[35]

At the same time, the European guidelines on chronic insomnia, which evaluate the current body of clinical research, do not recommend herbal medicine as a treatment for insomnia. [36]

Both positions can exist simultaneously: the first refers to a specific herbal medicinal product and its regulatory use, the second to the choice of treatment for a chronic clinical disorder.

What is often misunderstood

"Valerian only works after accumulation." A pharmacokinetic study found no significant accumulation of valerenic acid after two weeks of regular use. The gradual effect cannot be explained by simple accumulation of the substance in the blood. [37]

"The minimum course is two weeks." There is no such universal standard. The period of 2-4 weeks refers to the well-established use of a specific dry extract in a European monograph. [38]

"If you take valerian for four weeks, it will definitely start working." No. In studies, regular use sometimes produced improvement, sometimes it was no different from placebo, and a review of reviews did not confirm reliable effectiveness for insomnia. [39]

"One pill is useless." Some dosage forms require a single evening dose. But its clinical effect is unpredictable. [40]

"A certain amount of time between courses is absolutely necessary." There is no evidence-based, universal break schedule. If courses must be repeated frequently, it's more appropriate to assess the underlying cause of the symptoms. [41]

"A natural remedy can be taken for months." The long-term safety of valerian is less well established than the short-term safety. [42]

Key points from experts

Christopher Drake, PhD, is a board-certified sleep medicine specialist and director of Sleep Research at Henry Ford Health. His research interests include insomnia, circadian disorders, and behavioral treatment of sleep disorders. [43]

Drake is one of the authors of a 2024 umbrella review on valerian and insomnia. The research team concluded that systematic reviews do not provide convincing evidence for the effectiveness of valerian for insomnia: possible subjective improvements in sleep quality are not accompanied by equally convincing quantitative and objective results. [44]

Dieter Riemann is an insomnia research specialist and one of the leaders of the revision of the European Insomnia Guidelines. The profile of the University Hospital Freiburg confirms his long-standing work with the European Society for Sleep Research and his leadership in updating the European guidelines. [45]

In the 2023 European Guidelines, the expert panel does not recommend herbal remedies for insomnia and considers cognitive behavioral therapy for insomnia to be the primary evidence-based strategy. This is especially important for people considering repeated courses of valerian due to chronic sleep problems. [46]

Frequently Asked Questions

Is it necessary to take valerian for 2-4 weeks?

No. This period is recommended by the EMA for a specific dry extract with well-established use. It is not a universal rule for all valerian. [47]

Can valerian be taken only once?

Yes, some sleep aid medications require a single dose taken approximately 30-60 minutes before bed. However, the effectiveness of a single dose is not guaranteed. [48]

Why then do they recommend the course?

For a given standardized extract, the EMA considers the onset of action to be gradual. Therefore, continuous use over several weeks is recommended for optimal effect. [49]

How many days should it take for the effect to appear?

There is no universal time frame. Some studies found changes after two weeks, while others found no effect even after this course. [50]

Should I wait four weeks if nothing has changed after two?

Not necessarily. The EMA suggests consulting a doctor if symptoms persist or worsen after two weeks of continuous use. [51]

Is it possible to drink valerian for a month?

In most adults, short-term use has been best studied. NCCIH reports acceptable safety at studied doses for up to six weeks, but long-term safety remains unknown. [52]

Can I take it continuously?

Long-term chronic use has been poorly studied and has no convincing evidence of benefit for chronic insomnia.[53]

Should I take a break after a month?

There is no proven mandatory break interval. It's best to consult the instructions for the specific medication and the reason for the new course being needed.

Does valerian have a cumulative effect?

The study did not detect any significant pharmacokinetic accumulation of valerenic acid after two weeks of administration. Therefore, the term "cumulative effect" in its simple sense is not entirely correct. [54]

Is it possible to simply stop taking it after the course?

After typical short-term use, there is no universal requirement to gradually reduce the dose. However, with long-term chronic use, rare withdrawal symptoms have been reported. [55]

Is it possible to repeat courses several times a year?

There is no universally proven protocol for repeat courses. If symptoms regularly recur, it is more helpful to determine the cause than to automatically begin another course.

Will a month-long course help with chronic insomnia?

Current guidelines do not recommend valerian as a treatment for chronic insomnia.[56]

Is it necessary to take a course of treatment for stress?

For mild nervous tension, a specific EMA preparation suggests gradual action. However, overall, the NCCIH considers the evidence for valerian's effectiveness for stress insufficient. [57]

Main

There is no universal rule that “valerian must be taken in a course.”

For a specific dry ethanol extract of valerian root, the EMA does recommend continuous use for 2-4 weeks, as it considers its action gradual. However, this applies to the specific dosage form and does not automatically apply to any tincture, tea, tablet, or dietary supplement. [58]

The idea of a course does not mean proven accumulation of valerian: after two weeks of regular use, the pharmacokinetic parameters of valerenic acid did not change significantly relative to a single dose. [59]

Clinical evidence also doesn't support the conclusion that regular use necessarily transforms an ineffective first dose into an effective treatment. Some small studies have found isolated improvements after two weeks, while others have not, and a modern umbrella review found no reliable evidence for the effectiveness of valerian for insomnia. [60]

Therefore, a reasonable approach is to follow the instructions for a specific registered medication, set a goal in advance, and evaluate the actual results. If symptoms persist after two weeks, if valerian is needed for months, or if the sleep problem has become chronic, it is more important to reassess the cause of the symptoms and the treatment than simply extend the next course.