Lovaza is a prescription medication used to treat very high triglyceride levels in adults, specifically those with levels at or above 500 mg/dL. It contains concentrated omega-3 fatty acids (EPA and DHA) derived from fish oil, but in a purified, standardized form that delivers far higher doses than over-the-counter fish oil supplements.
Why Triglycerides Above 500 mg/dL Matter
Triglycerides are a type of fat circulating in your blood. Normal levels fall below 150 mg/dL. Once they climb past 500 mg/dL, the condition is classified as severe hypertriglyceridemia, and it carries a real risk of pancreatitis, a painful and potentially dangerous inflammation of the pancreas. That threshold is why Lovaza exists as a prescription rather than a lifestyle suggestion. It’s not prescribed for moderately elevated triglycerides or general heart health.
How Lovaza Lowers Triglycerides
The exact mechanism isn’t fully understood, but the general picture is clear. The EPA and DHA in Lovaza work primarily in the liver, where most triglycerides are produced. These omega-3 fatty acids are poor raw materials for the enzymes that build triglyceride molecules, so when the liver takes them up, triglyceride production slows down. At the same time, Lovaza appears to increase the rate at which the liver burns off fatty acids for energy and boost the activity of enzymes in the bloodstream that break down triglyceride-rich particles.
The net effect: less fat gets packaged and released into your blood. In clinical trials of patients with triglycerides between 500 and 2,000 mg/dL, Lovaza reduced triglyceride levels by a median of about 45% over study periods of 6 to 16 weeks.
How It’s Taken
The standard dose is 4 grams per day, which works out to four capsules. You can take all four at once or split them into two capsules twice daily. Lovaza should be taken with food, as that’s how it was administered in the clinical trials that established its effectiveness. Each capsule is a large, soft gelatin pill filled with an oily liquid, so swallowing them on an empty stomach can also make digestive side effects worse.
How Lovaza Differs From Fish Oil Supplements
This is a common point of confusion. Over-the-counter fish oil capsules typically contain 300 to 500 mg of combined EPA and DHA per pill, along with other fats. Lovaza capsules each contain approximately 900 mg of omega-3 ethyl esters in a concentrated, pharmaceutical-grade form. To match the omega-3 content of four Lovaza capsules, you’d need to take a large handful of standard fish oil pills, and the purity and consistency wouldn’t be guaranteed.
Because Lovaza is an FDA-approved drug, its manufacturing is held to pharmaceutical standards for potency, purity, and contamination limits. Supplement-grade fish oil is not regulated the same way. This distinction matters for people whose triglycerides are dangerously high and who need reliable, predictable dosing.
Common Side Effects
Lovaza is generally well tolerated, but it does cause digestive issues in a notable percentage of users. In pooled data from 23 clinical studies involving 655 patients on Lovaza and 370 on placebo:
- Burping (eructation): 4% of Lovaza users vs. 1% on placebo. The burps often carry a fishy taste or smell.
- Taste changes: 4% reported an unusual or unpleasant taste, compared to less than 1% on placebo.
- Indigestion: 3% experienced stomach discomfort, vs. 1% on placebo.
Taking the capsules with a meal and keeping them refrigerated can reduce the fishy aftertaste and burping. Some people find splitting the dose into two servings per day helps as well.
Effects on Other Cholesterol Numbers
One thing to be aware of: while Lovaza is effective at lowering triglycerides, it can raise LDL cholesterol (the “bad” cholesterol) in some patients. This is a known effect of omega-3 medications that contain both EPA and DHA. Your prescriber will typically monitor your lipid panel periodically to check for this. If LDL levels rise significantly, additional treatment may be needed to manage it.
Heart Rhythm Concerns
Prescription omega-3 products, including Lovaza, have been associated with an increased risk of atrial fibrillation or atrial flutter, a type of irregular heartbeat. This risk appears to be relatively small in clinical trials, but it’s worth knowing about, particularly if you already have a history of heart rhythm problems. Symptoms to watch for include a fluttering sensation in your chest, an unusually fast or irregular heartbeat, dizziness, or shortness of breath.
Who Should Not Take Lovaza
Lovaza is contraindicated in anyone with a known hypersensitivity to the medication or any of its ingredients. Because the omega-3s are derived from fish, there has been longstanding debate about whether people with fish or shellfish allergies should avoid it. The risk of a serious allergic reaction appears to be very low, but if you have a severe fish allergy, your prescriber will weigh that risk before starting you on the medication.
People taking blood thinners should also be monitored carefully, since omega-3 fatty acids at high doses can prolong bleeding time. This doesn’t necessarily mean you can’t take Lovaza alongside a blood thinner, but your prescriber needs to know about all medications you’re using.