Pharmacy shelves are full of vitamins and supplements that promise to relieve stress. A few have some research behind them, most have very little, and one or two carry real risks. This guide looks at seven of the most widely sold, what the evidence says about each, and what to check before you take them.
At a glance
| Supplement | What the evidence says | Main cautions |
|---|---|---|
| Ashwagandha | Some preparations may help with stress and sleep. Unclear for anxiety. | Rare cases of liver injury. Avoid in pregnancy, breastfeeding, and thyroid or autoimmune conditions. |
| Melatonin | Helps with jet lag and some sleep timing problems. It is a sleep aid, not a stress treatment. | Drowsiness, headache. Can interact with blood thinners and epilepsy medicines. |
| Rhodiola | Not enough reliable evidence for any use. | Dizziness, headache, sleep problems. Can interact with some blood pressure medicines. |
| L-theanine | Small studies only. No firm conclusion. | Generally well tolerated. Check with your pharmacist if you take other medicines. |
| Glycine | Small studies on sleep quality only. | Little is known about long-term use. |
| B vitamins | Useful if you are deficient. Little evidence of benefit for mood in well-nourished people. | High doses of vitamin B6 over time can damage nerves. |
| Kava | May help anxiety after several weeks of use. | Risk of serious liver injury. Do not combine with alcohol or sedatives. |
1. Ashwagandha
Ashwagandha is a herb used in traditional Indian medicine. Research suggests that some preparations may help with stress and insomnia, although the evidence for anxiety is unclear. It appears to be safe for up to three months, but long-term safety is not known. There have been cases of liver injury linked to it. Do not use it if you are pregnant or breastfeeding, have a thyroid or autoimmune condition, or are about to have surgery. It can interact with medicines for diabetes, blood pressure, thyroid problems, seizures and sleep.
2. Melatonin
Melatonin is a hormone the brain releases in response to darkness. Supplements can help with jet lag and with falling asleep earlier when your body clock has shifted. Poor sleep and stress feed each other, which is why it is marketed for stress, but it does not treat stress itself. Short-term use seems safe for most adults. Side effects are usually mild: headache, dizziness, nausea and drowsiness. Speak to your doctor first if you take blood thinners or epilepsy medicine, or if you are pregnant or breastfeeding.
3. Rhodiola
Rhodiola is promoted for stress, fatigue and mood. The existing studies in people are of low to moderate quality, and there is not enough reliable evidence to say that it works for any health purpose. It is possibly safe for up to 12 weeks. It can cause dizziness, headache and sleep problems, and it interacts with losartan, a blood pressure medicine.
4. L-theanine
L-theanine is an amino acid found in tea. A handful of small studies suggest it may have a calming effect, but they are too small and too varied to draw a firm conclusion. A cup of tea gives you a modest amount along with caffeine, which can make some people more jittery.
5. Glycine
Glycine is an amino acid that the body makes itself. A few small studies have looked at whether taking it before bed improves sleep quality. The research is limited, and there is no good evidence that it relieves stress directly.
6. B vitamins
B vitamins help the body to produce energy and keep the nervous system working. If you are low in one of them, correcting it can improve tiredness and mood. Low vitamin B12, for example, can cause low mood, confusion and memory problems. In people who are not deficient, vitamin B6 supplements do not appear to improve mood. More is not better: taking high doses of vitamin B6 for a long time can cause nerve damage. Stay within the dose on the label and avoid taking several products that all contain B6.
7. Kava
Kava is a plant from the South Pacific. It may help with anxiety if taken for several weeks, although it does not appear to work for generalised anxiety disorder. The concern is safety: kava has been linked to rare but severe liver damage. Do not combine it with alcohol or sedative medicines, and do not use it in pregnancy or while breastfeeding. Speak to your doctor before trying it.
Before you buy any supplement
- Tell your doctor or pharmacist what you are taking, especially if you use prescription medicines.
- Do not take supplements in pregnancy or while breastfeeding unless a health professional has advised it.
- Be cautious with products that list many ingredients or make dramatic promises. What is on the label is not always what is in the bottle.
- Stop and get advice if you develop yellowing of the skin or eyes, dark urine, itching or tummy pain. These can be signs of a liver problem.
What does help with stress
The approaches with the most support cost little or nothing:
- Be active. Exercise will not remove the cause of your stress, but it takes the edge off.
- Stay in touch with friends and family.
- Set aside time for things you enjoy.
- Do not lean on alcohol, smoking or caffeine to cope.
- Prioritise the tasks that matter and accept that you cannot do everything.
- Focus on what you can change and let go of what you cannot.
- Protect your sleep with regular hours.
When to see a doctor
See your doctor if stress is affecting your sleep, work or relationships for more than a couple of weeks, if you feel low or anxious most of the time, or if you are relying on alcohol or medication to get through the day. If you have thoughts of harming yourself, speak to a doctor or a crisis service straight away.
This article is for general information and does not replace advice from your doctor or pharmacist.
Medically reviewed by the ASAIPA clinical team.
