Does fish oil help with anxiety? What the research does and doesn't show

The evidence doesn't support fish oil, at a standard 300-600 mg/day serving, as a treatment for anxiety. Two meta-analyses found a benefit only in trials using at least 2,000 milligrams of omega-3 a day — more than three times a typical fish oil softgel dose — and rated the overall certainty of evidence low to very low.

What the evidence doesn't support

It doesn't support fish oil, at a standard consumer dose, as a treatment for anxiety, panic disorder or generalized anxiety disorder. Both reviews below found that the anxiety-reducing association only reached statistical significance in the higher-dose portion of the trials — around 2,000 mg/day of combined omega-3 or more. Neither review found a benefit below that threshold. A softgel supplying 300-600 mg a day, the range most over-the-counter fish oil products fall into, sits well under the dose where either analysis found an effect.

What the trials found

A 2018 systematic review and meta-analysis pooled 19 clinical trials, 2,240 participants total, searched across eight databases. Omega-3 treatment was associated with a reduction in anxiety symptoms overall (Hedges g 0.374, a small-to-moderate effect), and the association was stronger in people with a diagnosed clinical condition than in general samples. Critically, the anxiolytic effect was statistically significant only in the subgroup of trials using at least 2,000 mg/day — the lower-dose trials, taken together, did not show a significant effect.

A 2024 dose-response meta-analysis of 23 randomized trials, 2,189 participants, tested this more directly by modeling the dose-response relationship itself. Each additional gram per day of omega-3 was associated with a moderate reduction in anxiety symptoms, but the certainty of that overall estimate was rated low. The non-linear analysis found the largest estimated benefit at 2 g/day specifically, and — matching the 2018 review — found that doses lower than 2 g/day did not affect anxiety symptoms. The same analysis found omega-3 did not increase adverse events compared with control.

Both reviews, in other words, converge on the same dose threshold from two independent samples of trials: an effect shows up around 2,000 mg/day and above, and doesn't reliably show up below it. Neither trial pool isolated fish oil specifically as a form, and neither tested a dose in the 300-600 mg/day range that a standard softgel provides.

Questions people ask

Does fish oil help with anxiety?

At the doses most fish oil supplements provide — a few hundred milligrams a day — the evidence doesn't show a benefit. The two meta-analyses that looked at dose specifically found an effect only at 2,000 mg/day or more.

Can omega-3 help with anxiety?

At a high enough dose, two meta-analyses found an association with reduced anxiety symptoms, rated low to very low certainty. That dose — around 2,000 mg/day and above — is well beyond what a standard fish oil serving supplies.

Does fish oil cause anxiety?

Neither meta-analysis reviewed here found that omega-3 supplementation increased anxiety or other adverse events compared with control.

How much fish oil would I need for anxiety?

The research reviewed above associates a possible effect with roughly 2,000 mg/day of combined omega-3 — several times a typical softgel serving — and the certainty behind that number is low. This page isn't a recommendation to take that amount; it's a report of where the trials that found an effect were dosed.

Will omega-3 help with anxiety and depression together?

These are reviewed separately because they're different bodies of research; see fish oil and depression: what the research shows for what the depression-specific trials found.

When to talk to a doctor

Anxiety that interferes with daily life, work or sleep is worth raising with a doctor. Fish oil is not a treatment for anxiety, panic disorder or generalized anxiety disorder, and nothing in the evidence above supports using it as a substitute for an evaluation, therapy or medication a doctor might recommend. If you take medication for anxiety or any other condition, or are pregnant or nursing, talk to a doctor before adding any supplement.

Sources

• Su KP, et al. Association of Use of Omega-3 Polyunsaturated Fatty Acids With Changes in Severity of Anxiety Symptoms: A Systematic Review and Meta-analysis. JAMA Netw Open 2018. PMID 30646157.
• Bafkar N, et al. Efficacy and safety of omega-3 fatty acids supplementation for anxiety symptoms: a systematic review and dose-response meta-analysis of randomized controlled trials. BMC Psychiatry 2024. PMID 38890670.

Related reading: fish oil and depression: what the research shows and how much fish oil should you take a day.