The Five Most Effective Evidence-Based Supplements for Anxiety

Introduction

This article presents the five most effective natural supplements for the management of anxiety, selected following a comprehensive review of current scientific literature. The inclusion of each supplement is based on the strength and consistency of evidence demonstrating therapeutic benefit, the quantity and quality of studies supporting their use, and their safety profiles, with particular consideration given to the relative absence of significant adverse effects. Each supplement will be discussed with reference to key research findings and relevant clinical studies.

In addition, certain nutritional abnormalities are commonly observed in individuals with anxiety. These will be detailed after the list of supplements, as addressing them, where present, is recommended not only for overall health but also because their correction has been shown to reduce anxiety symptoms.

Advisory: As with any supplement, it is strongly advised to consult a qualified healthcare professional before starting. This precaution ensures that any potential medical conditions or concurrent prescription medications are appropriately considered. This article is intended solely as an evidence-based overview.

1. Ashwagandha

Ashwagandha (Withania somnifera) extract has been shown in multiple clinical trials to reduce both anxiety and stress. A recent systematic review of 12 studies with a cumulative sample size of 1,002 participants found that ashwagandha significantly reduced symptoms of anxiety and stress when compared with placebo [1].

For anxiety, greater benefits were observed at higher daily doses of the extract (≥600 mg). For stress, improvements were seen across both lower (<600 mg) and higher (≥600 mg) doses. In a placebo-controlled trial, both 250 mg and 600 mg daily of ashwagandha root extract reduced perceived stress and lowered cortisol levels—a key marker of stress—with participants also reporting improved sleep quality [2].

References:

[1] Akhgarjand C, et al. Phytother Res. 2022; Wiley Online Library

[2] Salve J, et al. Cureus. 2020; PMC6979308

2. Passion Flower

Passion flower (Passiflora incarnata) supplementation has shown encouraging results in reducing anxiety symptoms. While its long-term safety and optimal dosing remain uncertain, and some aspects of its active constituents are not yet fully understood, current evidence suggests notable therapeutic potential.

In either droplet or tablet form, passion flower has demonstrated reductions in anxiety comparable to benzodiazepines—agents generally reserved for short-term use due to their addictive potential and long-term side effects [3]. For example, a double-blind trial found passion flower extract to be as effective as oxazepam in generalised anxiety disorder, without impairing daily performance [4]. Other research has shown it to reduce pre-operative anxiety with similar efficacy to midazolam, but with fewer cognitive side effects [5].

There are currently no standardised dosage guidelines; however, clinical studies using capsules or tablets have often administered around 500 mg of passion flower extract daily. Studies using slightly higher or lower doses have not demonstrated substantially different therapeutic outcomes.

References:

[3] Movafegh A, et al. Anesth Analg. 2008; PubMed 

[4] Akhondzadeh S, et al. J Clin Pharm Ther. 2001; Wiley Online Library

[5] Dantas LP, et al. Med Oral Patol Oral Cir Bucal. 2017; PubMed

3. Lavender

Studies investigating the effects of lavender on anxiety have produced promising results. However, some findings should be interpreted with caution due to potential biases. As the scent of lavender is easily recognisable, creating a reliable placebo for comparison is challenging.

Despite this, inhalation of lavender during aromatherapy sessions has consistently been associated with reductions in anxiety symptoms. No specific dosage has yet been established for aromatherapy use.

A controlled study evaluating oral lavender oil capsules found that daily doses of both 80 mg and 160 mg were superior to placebo in reducing anxiety and stress, as well as promoting a sense of calm [6]. The suggested oral dose is 80–160 mg per day, with supplements ideally containing 25–46% linalyl acetate and 20–45% linalool to achieve a therapeutic effect [7].

Lavender oil has a favourable safety profile, with minimal side effects and no evidence of withdrawal symptoms. While further well-designed trials are needed to establish standardised guidelines for its use, current evidence supports its potential as a viable option for anxiety management [8].

References:

[6] Kasper S, et al. Int J Neuropsychopharmacol. 2014; Cambridge University Press

[7] Spiess D, et al. Front Pharmacol. 2021; PMC9519192

[8] Donelli D, et al. Phytomedicine. 2019; Elsevier

4. Cannabidiol (CBD)

Current evidence suggests that cannabidiol (CBD) may act as an effective anxiolytic. However, its marketing has considerably outpaced the strength of supporting evidence from well-controlled clinical studies.

For therapeutic purposes, oral administration—either as capsules or oil—remains the recommended route. Clinical trials generally indicate a reduction in anxiety symptoms following CBD use. Evidence also suggests an inverted U-shaped dose–response relationship, with a likely minimum effective single dose of around 300 mg; doses significantly higher or lower than this may be less effective [9].

CBD, when dosed appropriately, is typically well tolerated. It may, however, interact with certain medications via cytochrome P450 metabolism, so caution is advised for those taking medications with a narrow therapeutic index.

References:

[9] Arnold JC, et al. Cannabis Cannabinoid Res. 2023; PMC9841308

5. Saffron

Saffron (Crocus sativus) is a spice derived from the dried stigmas of the saffron crocus flower, traditionally used for culinary and medicinal purposes. Emerging evidence suggests it can reduce anxiety symptoms, although the number of high-quality clinical trials remains limited.

Most studies investigating saffron for anxiety have used a daily dose of 30 mg, typically divided into two 15 mg doses, usually in capsule form. Supplements are often standardised to the active constituents crocin and safranal, which are thought to contribute to its therapeutic effects [10].

Saffron is generally well tolerated at clinically studied doses. Substantially higher intakes may lead to detrimental effects and have not been shown to provide greater therapeutic benefit; therefore, such doses should be avoided.

References:

[10] Marx W, et al. Nutr Rev. 2019; Oxford Academic

Notable Supplements Excluded from the List

A number of other supplements have been investigated for their potential effects on anxiety that are not included here. In most cases, this is because available studies have either produced mixed results regarding efficacy or raised concerns about the risk of significant side effects. Examples include omega-3 fatty acids, L-theanine, probiotics, valerian root, St John’s wort, chamomile, glycine, rhodiola rosea, gamma-aminobutyric acid (GABA), inositol, and kava. The combination of L-lysine and L-arginine has also shown promise in reducing both stress and anxiety; however, this is currently supported by only two published studies. 

While each of these supplements has its own potential merits—and some have demonstrated benefits in other emotional or mental health conditions—their specific utility for anxiety remains limited at present.

Nutritional Imbalances Associated with Anxiety

Magnesium and Zinc

Magnesium is an essential mineral and a cofactor for over 300 enzymatic reactions in the body. Deficiency has been linked to a range of health conditions, including anxiety. Zinc, another essential nutrient, is also more frequently deficient in individuals with anxiety disorders [11,12]. While high-quality clinical evidence is limited, supplementation in deficient individuals has been associated with improvements in anxiety symptoms and is otherwise indicated for maintaining general health. Given the increased likelihood of deficiency in those with anxiety, assessing and correcting low magnesium or zinc levels is a worthwhile consideration.

Vitamin B6, Vitamin B9, Vitamin B12, and Vitamin D

Deficiencies in these vitamins are common in the general population and appear to be more prevalent in individuals with anxiety-related disorders. Although the evidence directly linking supplementation to anxiety reduction is less robust than for some other nutrients, ensuring adequate levels—particularly when deficiencies are confirmed—supports overall mental and physical well-being. Supplementation in such cases may also complement broader anxiety management strategies [13].

References:

[11] Boyle NB, et al. Nutrients. 2017;9(5):429. PMID: 28445426

[12] Swardfager W, et al. Front Psychiatry. 2023;14:1206893. PMID: 37364014

[13] Borges-Vieira JG, et al. Nutr Neurosci. 2022; Taylor & Francis Online

Conclusion

This overview has outlined the key considerations for supplementation and nutritional deficiencies relevant to anxiety. The volume of available information can be confusing, particularly given the commercial market’s tendency to overstate efficacy. The evidence presented here summarises the most effective, well-supported supplements, along with relevant nutritional deficiencies to address, for those seeking to manage anxiety.