NZ GLP-1 hub · Supplements · 5 November 2026 · Peer-reviewed
Omega-3 (fish oil): heart health claims, checked
General information, not advice. Supplements can interact with medicines. Talk to your doctor or pharmacist before starting one, especially if you take other medicines, are pregnant, or have a kidney or liver condition.
Why people take it
Omega-3 fats (EPA and DHA) are found in high amounts in oily fish such as salmon, sardines and mackerel. People take fish-oil capsules for heart health, joints and brain health.
Why it comes up with GLP-1 medicines
Eating less can mean eating less oily fish. We found no evidence that GLP-1 medicines change omega-3 needs.
What the evidence shows
Observational studies link eating more fish with a lower risk of heart disease. For capsules, the trials are mixed. VITAL found ordinary-dose fish oil did not reduce major heart events overall. REDUCE-IT did find a reduction, but it used a high dose of a purified prescription product in people with high triglycerides who were already on statins. That isn't the same as a supermarket capsule.
What it doesn't show
A 2026 review of keeping lean mass on GLP-1 treatment describes omega-3 as an add-on, supported mainly by indirect evidence.
Who should be careful
- →People on blood thinners such as warfarin: fish oil may prolong clotting times, although most research has not found clinically significant bleeding. Tell your doctor or pharmacist before starting it.
- →Trials of higher intakes have found a small increase in atrial fibrillation (an irregular heart rhythm).
- →Fish-oil capsules can cause an unpleasant taste, heartburn and nausea, which may add to GLP-1 nausea.
Food first
American Heart Association advisories recommend one to two servings of seafood a week. If you're considering a capsule for a heart condition, talk to your GP.
Sources
- NIH Office of Dietary Supplements — Omega-3 fatty acids, health professional fact sheet
- Manson JE et al. — Marine n−3 fatty acids and prevention of cardiovascular disease and cancer (NEJM) · 2019-01-03
- Bhatt DL et al. — Cardiovascular risk reduction with icosapent ethyl for hypertriglyceridemia, REDUCE-IT (NEJM) · 2019-01-03
- Gencer B et al. — Effect of long-term marine omega-3 fatty acids supplementation on the risk of atrial fibrillation in randomized controlled trials: a systematic review and meta-analysis (Circulation) · 2021-12-21
- Šantić R et al. — Lean mass and musculoskeletal preservation in GLP-1-based obesity treatment (Metabolites) · 2026
Review: Founder review via PR merge. General information only; no recommendations, brands, prices or product links; sources verified 5 Nov 2026.
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