Guide · 3 min read

How long to trial a remedy before deciding

Short answer

It depends on the remedy, and each ingredient entry gives its own timescale. Some are judged on the first dose or the first few days, and others took 4 to 12 weeks in trials. Judge a remedy on the dose, form and duration that were studied, keep a simple log, and set a stop date before you begin. A few remedies have a maximum length of use, and for those ‘trial it longer’ does not apply.

A closed notebook and a pen beside a cup of herbal tea

Some work quickly

These are judged within a day or two, or within a couple of weeks at most. The figures come from our ingredient entries, and each card links to the full entry.

Hours to a dayMelatonin for jet lagThe Cochrane review found nine of ten placebo-controlled trials showed less jet lag on flights crossing five or more time zones, with melatonin taken near the destination bedtime (10 pm to midnight). Our entry says to judge it over the first few days after arrival. ^[1]One doseGinger for travel sicknessThe EU monograph lists 1 to 2 g taken an hour before travel. Our entry notes NCCIH says most motion-sickness studies have not shown a benefit, so a single journey is a fair test but not proof. ^[2][11]Days to two weeksPeppermint oil for IBS symptomsThe EU monograph says IBS symptoms usually resolve within one or two weeks of enteric-coated oil capsules. If nothing has changed after 2 weeks, or symptoms worsen, it advises seeing a doctor or pharmacist. ^[3]OvernightSenna for constipationThe effect starts 8 to 12 hours after a dose, which is why it is taken at night. A single dose is a fair test, and the EU monograph advises seeing a doctor or pharmacist if it has not worked, rather than increasing the dose or duration. ^[8]

Some take weeks

For these, a few days tells you very little. The trials ran for weeks, so that is the only fair way to judge them.

Up to 4 weeksSt John's wort for mild to moderate depressionThe EU monograph says the effect can be expected within 4 weeks, and to consult a doctor if symptoms persist during use. ^[4]4 to 12 weeks in trialsSaffron for low moodThe trials in the 2026 meta-analysis lasted at least 4 weeks, and our entry gives 4 to 12 weeks as the studied range. Results varied a lot between trials, and long-term safety beyond a few months is not established. ^[5]8 weeks or moreAshwagandha for sleepThe sleep meta-analysis found larger effects in people with diagnosed insomnia, at 600 mg a day or more, and with 8 weeks or more of treatment. Our entry says to judge it over 8 weeks, the length most trials ran. ^[6]A month or morePsyllium for chronic constipationA 2022 meta-analysis found doses above 10 g a day and at least 4 weeks worked best. Judging it after a few days on a small dose would not match what was tested. ^[7]

Match the trial to what was studied

A lower dose for less time is not a test of what the trials found. Two examples from our entries: the psyllium constipation result was clearest above 10 g a day and after at least 4 weeks^[7], and the ashwagandha sleep effects were larger at 600 mg a day or more and after 8 weeks or longer^[6].

Form matters as well. Most saffron trials used standardised extracts, so plain saffron threads are not equivalent^[5]. If the product you have is a different form or strength, the trial figures do not carry over. See Is a tea as effective as a capsule?

Some have an upper limit

The EU herbal monographs set a maximum length of use for some remedies. If nothing has changed by then, the answer is to see a doctor or pharmacist, not to carry on.

Senna. No more than 1 week; two to three doses in that week are usually enough. ^[8]
Liquorice. No more than 4 weeks for digestive symptoms, and see a doctor if symptoms last beyond 2 weeks. ^[9]
Devil's claw. See a doctor or qualified practitioner if joint pain persists beyond 4 weeks, or digestive symptoms beyond 2 weeks. ^[10]
Ginger. The EU monograph advises seeing a doctor if digestive complaints or loss of appetite persist beyond 2 weeks, or joint pain beyond 4 weeks. ^[2]

A good result is not a reason to go past the limit

A remedy that seems to be working can still be one where the regulator says not to carry on. For liquorice, the EU monograph reports water retention, low potassium, high blood pressure and heart rhythm disorders with longer use or high intakes^[9]. Check the entry’s duration limit before you decide to continue.

Keep a log, change one thing, set a stop date

Score the symptom before you start. A simple 0 to 10 rating for the thing you want to change, for example sleep quality or pain, and note the date.
Change one thing at a time. Start one remedy, and hold off on other new supplements or big routine changes, so you can tell what caused any difference.
Write down the product, dose and time you take it. Score again at the same time of day, weekly for the slower remedies.
Set a stop date before you begin, based on the timescale in the entry and any duration limit. On that day, compare your scores and decide.

When to stop early and see a doctor

New or worsening symptoms. Peppermint oil for IBS symptoms, for instance, comes with advice to see a doctor or pharmacist if symptoms worsen^[3].
Warning signs listed in the entry. Our ashwagandha entry says to stop and speak to a doctor for yellow skin or eyes, dark urine, itching or persistent nausea. Our butterbur entry lists yellow skin or eyes, dark urine or persistent tiredness.
Symptoms that outlast the self-care window. EU monographs often say to consult a doctor if symptoms persist: beyond 2 weeks for ginger’s digestive uses^[2] and liquorice^[9], and beyond 4 weeks for joint pain with ginger or devil’s claw^[2][10].
A serious condition. For St John’s wort our entry says severe depression or suicidal thoughts need a doctor, not self-treatment. If you feel seriously unwell, get urgent medical help.

Do not stop a prescribed medicine on your own because of a remedy trial. Ask the prescriber.

Questions people ask

What if I feel nothing after a week?

That depends on the remedy. For senna or peppermint oil, a week is already a long time and the EU monographs advise seeing a doctor or pharmacist rather than carrying on. For St John's wort the EU monograph expects the effect within 4 weeks, and for ashwagandha and sleep the trials ran 8 weeks or more. Check the entry for the timescale it gives, and do not raise the dose to speed things up.

Can I keep taking it if it seems to be working?

Only within the limits in its entry. Senna is limited to 1 week and liquorice to 4 weeks by the EU regulator. For others, our entries say long-term safety has not been established, for example for saffron beyond a few months. If you want to continue past the studied duration, ask a pharmacist or doctor.

Should I start two remedies at once?

It is better not to. If your symptoms change you will not know which one caused it, and that includes side effects. Start one, keep the log below, and add the next only after the first trial has finished. Run any combination through our interaction checker first.

Sources

Draft, awaiting clinical review