Can I Take Omega-3 (EPA/DHA) With Wegovy?

Does Wegovy's label list an interaction with omega-3?

No. Wegovy's drug interactions section covers two situations. The first is insulin or an insulin secretagogue such as a sulfonylurea, where the concern is hypoglycemia [1]. The second is other oral medicines, where delayed gastric emptying may change absorption; the label cites a 33% increase in levothyroxine exposure with the tablet form and advises closer monitoring for drugs with a narrow therapeutic index [1].

Omega-3 supplements and prescription omega-3-acid ethyl esters do not appear in that section. The label also records that in clinical pharmacology trials with semaglutide 1 mg once-weekly injection, semaglutide did not affect the absorption of the oral medicines tested [1].

How semaglutide is cleared, and the administration instructions

Semaglutide is a peptide. It is broken down by proteolytic cleavage of the peptide backbone and beta-oxidation of its fatty acid side chain rather than by cytochrome P450 enzymes, and the label describes a very low potential to inhibit or induce CYP enzymes [1]. Its half-life is about a week [1].

The omega-3-acid ethyl esters label reports that in vitro work with human liver microsomes found clinically significant CYP-mediated inhibition by EPA and DHA combinations is not expected in humans [2].

On administration, the Wegovy label allows the once-weekly injection at any time of day, with or without meals [1]. The omega-3 capsules were given with meals in the clinical studies [2]. For Wegovy tablets, the label says to take them on an empty stomach with up to 4 ounces of plain water and to wait at least 30 minutes before eating, drinking or taking other oral medicines [1].

What the labels say about bleeding

The prescription label here is the omega-3-acid ethyl esters label (the Lovaza-type product, 4 grams a day), not an over-the-counter fish oil label. It says that some trials with omega-3 acids showed prolongation of bleeding time, that the prolongation reported did not exceed normal limits and did not produce clinically significant bleeding episodes, and that clinical trials have not thoroughly examined the combination with anticoagulants. It advises periodic monitoring for patients taking an anticoagulant or antiplatelet drug [2].

That label dose is 4 grams a day of EPA and DHA ethyl esters. Over-the-counter capsules vary widely in EPA plus DHA content, so the EPA and DHA amounts on the label matter more than the "fish oil" milligram figure [2]. Neither "no effect on bleeding" nor "dangerous with a blood thinner" is established; the label position is monitoring [2].

Does higher-dose omega-3 increase atrial fibrillation?

A 2021 meta-analysis of 7 randomized cardiovascular outcome trials and 81,210 patients, average follow-up 4.9 years, found marine omega-3 was associated with more atrial fibrillation (HR 1.25, 95% CI 1.07 to 1.46). By dose, the hazard ratio was 1.49 (1.04 to 2.15) in trials testing more than 1 g a day and 1.12 (1.03 to 1.22) at 1 g a day or less, rising 1.11 for each extra gram per day [3].

The omega-3-acid ethyl esters label describes a 663-person trial in people with paroxysmal or persistent atrial fibrillation who took 8 grams a day for 7 days and then 4 grams a day for 23 weeks. Recurrent symptomatic AF or flutter was more frequent on omega-3 than placebo, with a combined hazard ratio of 1.25 (95% CI 1.00 to 1.40), particularly in the first 2 to 3 months [2].

Wegovy's label separately lists heart rate increase: a mean rise of 1 to 4 beats per minute, and a rise of 20 beats per minute or more in 26% of treated patients versus 16% on placebo [1].

What do omega-3s do for triglycerides?

EPA and DHA lower triglycerides by about 15%, according to a 2020 review of 23 studies summarized by NCCIH, and that summary says they do not affect body fat or other lipids [5].

Prescription omega-3-acid ethyl esters are labeled only for severe hypertriglyceridemia (500 mg/dL or higher) as an adjunct to diet, and the label states that the effect on pancreatitis risk and on cardiovascular mortality and morbidity has not been determined [2]. The label says to assess triglyceride levels first and to identify other causes, including diabetes, hypothyroidism and triglyceride-raising medicines [2].

In two placebo-controlled trials totaling 84 adults with a baseline median triglyceride level of 792 mg/dL, 4 grams a day lowered median triglycerides, VLDL cholesterol and non-HDL cholesterol and raised median HDL cholesterol relative to placebo. LDL cholesterol can rise in some people, and the label advises periodic LDL-C monitoring [2].

Does fish oil add cardiovascular benefit on top of Wegovy?

The omega-3 outcome trials split by product and dose. In REDUCE-IT, icosapent ethyl 4 g a day in statin-treated, high-risk patients with raised triglycerides reduced the primary composite of cardiovascular death, nonfatal heart attack, nonfatal stroke, revascularization or unstable angina from 22.0% to 17.2% (HR 0.75, 95% CI 0.68 to 0.83) [4]. In VITAL, 1 g a day of marine n-3 fatty acids in 25,871 adults not selected for high risk produced 386 major cardiovascular events versus 419 on placebo (HR 0.92, 0.80 to 1.06), not significant [6]. STRENGTH tested 4 g a day of an EPA/DHA carboxylic acid formulation in 13,078 statin-treated high-risk patients against corn oil: 12.0% versus 12.2%, HR 0.99 (0.90 to 1.09), no benefit [7]. A Cochrane review of long-chain omega-3 trials found all-cause mortality RR 0.97 (0.93 to 1.01) and cardiovascular events RR 0.96 (0.92 to 1.01) [8].

Wegovy has its own outcome data. In SELECT, 17,604 adults with established cardiovascular disease and a BMI of 27 or higher, semaglutide 2.4 mg weekly reduced cardiovascular death, nonfatal heart attack or nonfatal stroke from 8.0% to 6.5% (HR 0.80, 0.72 to 0.90) [9]. These were separate trials, so they do not show whether adding fish oil to Wegovy adds cardiovascular benefit.

Practical points: burping, nausea and capsule choice

Both products cause upper-gut symptoms. In pooled trials of Wegovy 2.4 mg in adults with obesity, nausea occurred in 44% versus 16% on placebo, vomiting in 24% versus 6%, eructation in 7% versus under 1%, and dyspepsia in 9% versus 3% [1]. In 23 pooled trials of omega-3-acid ethyl esters, eructation occurred in 4% versus 1%, dyspepsia in 3% versus 2%, and taste perversion in 4% versus under 1% [2].

The formulation affects how much EPA and DHA reaches the blood. In 72 volunteers given about 3.3 g of EPA plus DHA daily for two weeks, bioavailability relative to natural fish oil was 73% for ethyl esters, 91% for free fatty acids and 124% for re-esterified triglycerides [10]. The big trials used 1 g a day in VITAL [6] and 4 g a day of icosapent ethyl in REDUCE-IT [4].

On allergy: the omega-3-acid ethyl esters label says it is not known whether people with fish or shellfish allergy are at higher risk of a reaction, advises caution in them, and contraindicates the product in anyone with a known hypersensitivity reaction to it or its components [2].