Best Supplements for Stress and Mood: What the Research Supports

Most lists of the best natural supplements for stress relief, calm and mood are built on marketing claims. This one is built on human research: which ingredients have been tested in randomized trials, what they actually changed, the doses used and how long they took. We make some of the products mentioned, and we say so where they come up.

The short answer: for everyday stress, ashwagandha and L-theanine have the strongest human evidence, with trials showing lower perceived stress and, for ashwagandha, lower cortisol. Saffron has the most research for low mood. B vitamins, rhodiola, magnesium, lemon balm and kanna have also been studied in human trials. If you want a natural calming supplement to help you relax, L-theanine and lemon balm have the most direct evidence for feeling calmer. Supplements can support a calmer mood and better stress resilience, but they are not a treatment for any condition.

Key Takeaways

• Best studied for stress: ashwagandha (daily, builds over weeks) and L-theanine (works within an hour).
• Best studied for mood: saffron extract, around 30 mg a day in most trials.
• Worth knowing: a meta-analysis found B vitamins helped stress.
• Match the tool to the job: daily adaptogens for ongoing stress, as-needed options for stressful moments.
• Check interactions: especially with antidepressants, sedatives, thyroid or blood pressure medicines.

Stress and Mood Supplements at a Glance

Supplement	What human studies found	Typical studied dose	Time to effect	Evidence
Ashwagandha	Lower perceived stress and cortisol; better sleep quality	250 to 600 mg root extract a day	2 to 8 weeks	Strong for a supplement
L-theanine	Lower stress-related symptoms and better sleep quality over 4 weeks; calmer response to acute stress	200 to 400 mg a day	30 to 60 minutes	Moderate
Saffron	Improved low mood across many small trials	About 28 to 30 mg extract a day	4 to 8 weeks	Moderate for mood
B vitamins	Small but significant benefit for stress in a meta-analysis of 16 trials	B complex, as labeled	4 weeks or more	Moderate
Rhodiola	Less stress-related fatigue and better attention in some trials	200 to 600 mg extract a day	1 to 4 weeks	Several trials
Magnesium	Studied for stress in people who run low, in a review of 18 studies	200 to 400 mg a day	Weeks	Systematic review
Lemon balm	More calmness during a stressful lab task after one dose	300 to 600 mg extract	1 to 3 hours	Single-dose study
Kanna	Lower amygdala reactivity and less nervousness before a public-speaking task	25 mg standardized extract	Under an hour	Single-dose trials

1. Ashwagandha

Ashwagandha (Withania somnifera) is an adaptogenic root from Ayurvedic tradition and the most researched herb for everyday stress. In one 8-week randomized trial of 60 stressed but healthy adults, 250 mg and 600 mg a day of root extract lowered perceived stress scores and serum cortisol compared with placebo and improved sleep quality, with the larger dose doing more. Several other trials have found similar results.

• Best for: ongoing, day-after-day stress and sleep disrupted by it.
• How to take it: 250 to 600 mg of a standardized root extract daily, with food; benefits build over 2 to 8 weeks.
• Safety: usually mild stomach upset or drowsiness. Rare cases of liver injury have been reported, and it may affect thyroid hormones. Avoid it if pregnant, and check with a clinician if you take thyroid, blood pressure, blood sugar, immune or sedative medicines.

Read our full comparison, ashwagandha vs L-theanine, our guide to ashwagandha side effects, and the ashwagandha ingredient page. To see how ashwagandha compares with bacopa, another traditional Indian herb, read our guide to bacopa vs ashwagandha.

2. L-Theanine

L-theanine is an amino acid from tea leaves that supports calm focus without sedation. In a 4-week randomized trial of 30 healthy adults, 200 mg a day reduced stress-related symptoms and improved sleep quality and some measures of verbal fluency compared with placebo. Other studies have found it blunts the rise in heart rate during a stressful task and increases alpha brain waves linked to relaxed alertness.

• Best for: stressful moments, racing thoughts, and smoothing out caffeine.
• How to take it: 100 to 200 mg as needed, up to 400 mg a day; it works within about an hour.
• Safety: very well tolerated; it can slightly lower blood pressure.

We make Theanine Nasal Spray, which delivers 36 mg of L-theanine per two-spray serving for as-needed calm. More in theanine nasal spray for fast calm focus. For pairing L-theanine with saffron, see our guide to saffron and L-theanine.

3. Saffron

Saffron extract, from the spice Crocus sativus, has one of the larger bodies of research for mood, with dozens of small randomized trials, most at about 28 to 30 mg a day for 6 to 8 weeks. The clearest results come from people with persistently low mood; results in otherwise healthy people are more modest. High culinary-grade doses are not needed, and very high doses are not advised in pregnancy. For the doses, trials and safety notes in detail, see our guide to saffron supplement benefits.

Coming soon from Synchronicity: our Saffron Mood and Calm Capsules pair saffron extract 28 mg with L-theanine 200 mg per serving in the planned formula. Join the waitlist on the product page to hear when they launch; no payment is taken. For saffron safety and daily amounts, see our guide to saffron side effects.

4. B Vitamins

A 2019 meta-analysis of 16 trials found B vitamin supplements gave a small but significant benefit for stress in healthy and at-risk adults. B vitamins matter most if your diet runs low, for example on a plant-based diet low in B12. Our Methyl B-12 Nasal Spray supplies B12 only; the trials mostly used B complex formulas.

5. Rhodiola

Rhodiola rosea is an adaptogen traditionally used for fatigue. Several trials suggest a standardized extract may ease stress-related fatigue and support attention, but many were small, short or lacked a placebo group. Some people find it mildly stimulating, so take it earlier in the day. See our rhodiola ingredient page.

6. Magnesium

A systematic review of 18 studies found the evidence suggestive of a benefit for stress in people prone to it, but judged the study quality poor. Magnesium is most likely to help if your intake is low, which is common. Glycinate and glycerophosphate forms tend to be gentle on the stomach; see our magnesium glycerophosphate page.

7. Lemon Balm

Lemon balm (Melissa officinalis) is a mint-family herb with a long history for calm. In a small 2004 study of healthy adults, a single 600 mg dose increased self-rated calmness during a stressful laboratory task. It is one of the ingredients in our Lithium Orotate Supplement, alongside reishi, vitamin B6 (P5P) and zinc; for how low-dose lithium fits in, see our lithium orotate guide.

If you would rather drink it, our guide to lemon balm tea covers how to make it, how much to drink and who should skip it.

8. Kanna

Kanna (Sceletium tortuosum) is a South African plant that acts on serotonin. In small trials, a single 25 mg dose of a standardized extract reduced the brain's threat response on imaging and eased nervousness before a public-speaking task. It must not be combined with antidepressants or other serotonin-raising products. Full details in our guide, what is kanna. We make Kanna Nasal Spray, which pairs kanna with theanine for as-needed use.

For how the brain chemicals behind mood compare, see our guide to dopamine vs serotonin.

For daily habits that support serotonin and which supplements should not be combined with antidepressants, see our guide on how to boost serotonin naturally.

What About Anandamide and PEA?

Our Anandamide Supplement combines anandamide, PEA, OEA and L-theanine to support the endocannabinoid system, which helps regulate mood and stress. Read more in anandamide supplements for mood. Kanna, anandamide and lithium orotate together make up our Mood Stack.

Natural Calming Supplements for Relaxation

A natural calming supplement is a plant extract, amino acid or mineral that supports a calmer, more relaxed state without being a sedative or a prescription drug. The ones with the most direct human evidence for feeling calmer are:

• L-theanine for relaxed alertness, during the day or in the evening, without drowsiness. See our L-theanine dosage guide for how much and when.
• Lemon balm for feeling calmer after a single dose.
• Magnesium if your intake runs low; many people take it in the evening to relax.
• Ashwagandha for ongoing stress and the sleep it disrupts, taken daily for several weeks.
• Kanna for as-needed calm before a stressful event, never with antidepressants.

For winding down at night, see sleep supplements without melatonin. Natural does not mean risk-free: several of these interact with medicines, so check with your pharmacist if you take any prescription medication.

To spot how stress shows up in your body, from headaches to poor sleep, see our guide to the physical symptoms of stress.

How to Choose

• For ongoing stress: a daily adaptogen such as ashwagandha, given 4 to 8 weeks.
• For stressful moments: something fast, such as L-theanine or kanna.
• For low mood: saffron has the most research; give it 6 to 8 weeks.
• If your diet is limited: check B vitamins and magnesium first.
• Quality: choose products with third-party tested ingredients, clear doses and no proprietary blends.
• Start one at a time so you can tell what helps.

Browse our mood supplements or read the stress and mood guide.

What you eat and drink matters as well; see which foods and drinks are linked to higher cortisol in studies.

For techniques you can use in the moment, see our guide on how to calm down fast.

When Supplements Are Not Enough

If stress or low mood lasts more than a couple of weeks, gets in the way of sleep, work or relationships, or comes with changes in appetite or energy, talk with a doctor or mental health professional. If you ever have thoughts of harming yourself, contact emergency services or a crisis line right away. For telling everyday tiredness from something bigger, see fatigue vs burnout.

Sources

• Salve J et al. Adaptogenic and Anxiolytic Effects of Ashwagandha Root Extract in Healthy Adults: A Double-blind, Randomized, Placebo-controlled Clinical Study. Cureus, 2019. PMC
• Hidese S et al. Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial. Nutrients, 2019. MDPI
• Young LM et al. A Systematic Review and Meta-Analysis of B Vitamin Supplementation on Depressive Symptoms, Anxiety, and Stress: Effects on Healthy and 'At-Risk' Individuals. Nutrients, 2019. PMC
• Boyle NB et al. The Effects of Magnesium Supplementation on Subjective Anxiety and Stress: A Systematic Review. Nutrients, 2017. PMC
• Kennedy DO et al. Attenuation of laboratory-induced stress in humans after acute administration of Melissa officinalis (Lemon Balm). Psychosomatic Medicine, 2004. PubMed

Related reading: NAD+ for stress and mood.

FAQs

What is the best supplement for stress and nervousness?

For everyday stress, ashwagandha and L-theanine have the most human research. Supplements can support a calmer mood, but they are not a treatment for any condition; persistent worry deserves a conversation with a clinician.

What is the fastest-acting supplement for stress?

L-theanine usually works within 30 to 60 minutes, and nasal sprays are designed for a faster onset, within minutes. Adaptogens such as ashwagandha take weeks.

Can I take ashwagandha and L-theanine together?

Yes, they work through different pathways and are commonly combined, with ashwagandha taken daily and L-theanine as needed.

What is a natural calming supplement?

A plant extract, amino acid or mineral that supports a calmer, more relaxed state without being a sedative or a prescription drug. L-theanine, lemon balm, magnesium and ashwagandha are common examples.

What are the best natural supplements for relaxation?

L-theanine and lemon balm for feeling calmer within hours, magnesium if your intake is low, and ashwagandha taken daily for ongoing stress and sleep.

What supplements help with mood?

Saffron extract has the most research for low mood. B vitamins help most when intake is low. Kanna and lemon balm have also been studied in human trials.

Are stress supplements safe with medication?

Not always. Kanna must not be combined with antidepressants, saffron should be discussed with your prescriber if you take mood medicines, ashwagandha can affect thyroid, blood sugar, blood pressure and sedative medicines, and L-theanine may add to blood pressure medicines. Check with your prescriber.

This article is for general education and is not medical advice. Our products are not intended to diagnose, treat, cure or prevent any disease. Talk with a qualified clinician before starting any new supplement, especially if you take prescription medication.