What are the best supplements for stress and anxiety?
None is a proven fix. Lavender oil, L-theanine, magnesium and ashwagandha have some trials, but none is an NHS treatment. And one popular herb is now under a UK safety review.
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What are the best supplements for stress and anxiety?
No supplement is an NHS treatment for anxiety. The NHS usually starts with talking therapy, usually CBT (cognitive behavioural therapy), which helps you change the thoughts and habits that feed worry.
Four supplements have been tested against a dummy pill (a placebo). Here is what the reviews of those trials found.
| Supplement | What trials found | The catch |
|---|---|---|
| Lavender oil capsules | 5 trials, 1,213 adults with anxiety: 80 mg a day for 10 weeks eased anxiety more than a dummy pill. | All tested one patented oil (Silexan). Can cause burping and stomach upset. |
| L-theanine | 9 trials: 200 to 400 mg a day may ease stress and anxiety in stressful situations. | The authors say bigger, longer trials are needed. |
| Magnesium | 18 studies in people prone to anxiety: a possible benefit. | Poor-quality evidence. No study measured stress with a proper questionnaire. |
| Ashwagandha | 12 trials, 1,002 adults: lower anxiety and stress scores. | Low certainty. Now under a UK safety review. |
Sources: Lavender review; L-theanine review; Magnesium review; Ashwagandha review
Think of each trial as one match against a dummy pill. A few small wins are a start. They’re not a title, so none of these has earned a place as a treatment yet.
If you still want to try one, run the safety checks further down first. Then read our guides to magnesium for anxiety and L-theanine.
Which herbs help with anxiety?
The Food Standards Agency got more and more reports of problems with ashwagandha supplements from 2021 to 2024, so its toxicity experts are reviewing them. A paper for them lists it among herbs often linked to liver injury; their statement was still a draft in September 2026.
Every lavender trial used one patented oil (Silexan), so we can’t assume the results apply to lavender tea or other oils. Side effects were mainly stomach problems.
In England it’s illegal to sell or import food containing kava.
Buying a herbal medicine? Look for a THR mark (a traditional herbal registration) and a product code from the MHRA (the UK medicines regulator).
Do vitamins help with stress and fatigue?
Stress vitamin packs lean on two lines of wording. UK law lets any product that’s at least a source of the nutrient use them.
| What the label says | Nutrients allowed to say it |
|---|---|
| Contributes to normal psychological function | Magnesium, vitamins B6, B12 and C, folate, niacin, thiamine, biotin |
| Contributes to the reduction of tiredness and fatigue | Magnesium, iron, vitamins B2, B6, B12 and C, folate, niacin, pantothenic acid |
Source: GB authorised health claims
The NHS says you should be able to get all the thiamin, riboflavin and niacin you need from your daily diet.
Tired as well as stressed? Stress is a common cause of tiredness. But if it lasts a few weeks and you don’t know why, see a GP.
They may check your blood for anaemia (too few healthy red blood cells), diabetes or an overactive thyroid.
An overactive thyroid can make you feel nervous, anxious and tired. Our anxiety blood test guide and vitamin B complex guide go further.
Are stress supplements safe?
Not for everyone. NICE tells doctors to talk about shop-bought products with people with generalised anxiety disorder (GAD, worry most days that affects everyday life). They should explain the risk of mixing them with other medicines, and the lack of evidence that they’re safe.
Before you buy a stress supplement
- Ask a pharmacist first if you take any other medicine, such as antidepressants, statins or the pill.
- Skip herbal medicines if you’re pregnant or breastfeeding, or have kidney or liver problems.
- Look for a THR mark and an MHRA product code on any herbal medicine.
- Don’t buy unlicensed herbal medicines online.
- Keep magnesium from supplements to 400 mg a day or less.
- Tell your GP or any doctor treating you what you take.
Sources: NHS: herbal medicines; NHS: magnesium
Other medicines that don’t mix well with herbs include blood thinners, and medicines for diabetes or blood pressure. Herbal medicines aren’t recommended for children.
More than 400 mg of magnesium can cause diarrhoea. Never stop or change a prescribed medicine without your prescriber. See also herbal supplements and liver damage.
What helps stress and anxiety more?
The free NHS route for stress and anxiety
- 1
Self-help
Breathing exercises, regular exercise, enough sleep and less caffeine.
- 2
Refer yourself
NHS talking therapies, if you’re 18 or over (16 in some areas).
- 3
See a GP
Usually talking therapy first, then medicine, usually a type of antidepressant.
- 4
Specialist team
A referral to a community mental health team.
Sources: NHS: GAD; NHS: stress
The NHS says running, walking, swimming and yoga can reduce anxiety and stress and help you sleep better.
Lots of coffee, tea, cola or energy drinks can make anxiety harder to control. The NHS also says not to use alcohol, cigarettes, gambling or drugs to relieve it.
You don’t need a GP to start. If you’re 18 or over (16 in some areas), you can refer yourself to NHS talking therapies.
Therapy is sometimes free through your employer, university or local charities too. Our stress management guide has more to try.
When to speak to a GP
- You feel anxious most of the time and it affects your everyday life.
- You’re struggling to cope with stress, or what you’re trying isn’t helping.
- You’ve felt tired for a few weeks and don’t know why, or you also have weight loss or mood changes. The NHS says to see a GP.
- Your skin or the whites of your eyes look yellow, maybe with itchy skin, darker pee or paler poo. Ask for an urgent GP appointment or call 111, and say what supplements you take.
Need help urgently, but it’s not an emergency? Call 111 and choose the mental health option. You can also call Samaritans on 116 123.
Call 999 or go to A&E if someone’s life is at risk, for example after serious self-injury or an overdose. Do the same if you can’t keep yourself or someone else safe.