Halibut is one of the best fish you can eat. It delivers 20 grams of protein per 100-gram serving at just 110 calories, with a mild flavor that works for people who don’t typically enjoy seafood. It also falls in a moderate range for mercury, making it safe for most people to eat regularly with some basic guidelines.
Protein and Calorie Profile
A 100-gram serving of halibut (roughly 3.5 ounces) contains about 21 grams of protein and only 110 calories. That protein-to-calorie ratio puts it among the leanest fish available, comparable to cod and tilapia but with a meatier, more satisfying texture. For anyone trying to hit high protein targets without excess calories, halibut is a strong choice.
Halibut is also rich in selenium, providing 36.5 micrograms per serving. That’s more than half of the daily recommended intake in a single portion. Selenium supports your thyroid function and acts as an antioxidant, helping protect cells from damage. You’ll also get meaningful amounts of magnesium and B vitamins, which play roles in energy production and nerve function.
Omega-3 Content Compared to Other Fish
Halibut contains omega-3 fatty acids, but less than fattier fish like salmon or mackerel. A 3-ounce cooked serving provides about 56 mg of EPA and 109 mg of DHA, the two omega-3s most closely linked to heart and brain health. That’s a combined 165 mg per serving.
For context, the same portion of salmon delivers roughly 1,000 to 1,800 mg of combined EPA and DHA. So while halibut contributes some omega-3s, it’s not a powerhouse source. If you’re eating halibut as your primary fish, you may want to supplement your omega-3 intake through other foods like walnuts, flaxseed, or sardines. If you’re eating a variety of seafood throughout the week, halibut fits well into that rotation without needing to carry the omega-3 load on its own.
Mercury Levels and How Much Is Safe
Halibut has a mean mercury concentration of 0.241 parts per million, based on FDA testing data. That places it in the moderate range, well below high-mercury fish like swordfish and king mackerel (which can exceed 0.7 ppm) but above low-mercury options like shrimp, salmon, and tilapia.
The FDA classifies halibut as a “Good Choice” rather than a “Best Choice” for seafood. The practical difference: most adults can safely eat halibut once a week without concern. Pregnant and breastfeeding women can have one 4-ounce serving per week from the “Good Choice” category, compared to two or three servings per week from the “Best Choice” list. If you’re pregnant and want to eat fish more frequently, pair one serving of halibut with additional servings of lower-mercury fish like salmon or pollock during the same week.
It’s worth noting that individual halibut can vary widely. The FDA data showed mercury levels ranging from undetectable all the way up to 1.52 ppm across 101 samples. Larger, older fish tend to accumulate more mercury, so smaller halibut fillets are generally a safer bet.
Flavor, Texture, and Cooking
One of halibut’s biggest selling points is its approachability. The flavor is mild and slightly buttery, without the strong fishiness that turns some people off. The flesh is firm and dense, holding together well during cooking, then flaking easily with a fork when done. This makes it forgiving for home cooks and versatile enough for nearly any preparation: pan-searing, baking, grilling, or poaching.
For best results, cook halibut to an internal temperature of 130°F. This keeps the interior moist and flaky rather than dry. Because halibut is a very lean fish with little fat to insulate it, overcooking is the most common mistake. A meat thermometer takes the guesswork out of it. Pull the fish from heat a few degrees early and let it rest, since the temperature will continue to climb slightly.
Picking Fresh Halibut
When buying halibut at the counter, look for fillets or steaks that are white to slightly translucent with an even color throughout. Avoid pieces with brown, gray, or yellowish spots. The surface should look slightly wet and glistening. If it appears dry or sticky, the fish has been sitting too long. Fresh halibut smells like a clean ocean breeze. Any strong, sour, or overly fishy odor means it’s past its prime.
Frozen halibut is a perfectly good alternative and often fresher than “fresh” counter fish, since it’s typically flash-frozen on the boat shortly after being caught. If buying frozen, look for vacuum-sealed packaging without visible ice crystals, which can indicate the fish has been thawed and refrozen.
Gout and Purine Considerations
Halibut falls in the moderate-purine category, containing 50 to 150 mg of purines per 100 grams. Purines break down into uric acid in your body, and high uric acid levels can trigger gout flares. If you have gout, you don’t necessarily need to avoid halibut entirely, but keeping portions modest and limiting how often you eat it (along with other moderate-purine foods) can help manage your risk. High-purine seafood like anchovies, sardines, and organ meats are the bigger offenders to watch for.