Liver is one of the most protein-dense organ meats available. Raw beef liver contains about 20 grams of protein per 100 grams, and that number climbs higher once cooked, since water evaporates during the cooking process. A single pan-fried slice of beef liver (roughly 81 grams) delivers 21.5 grams of protein, making it comparable to a similar-sized serving of chicken breast or lean steak.
Protein by Type of Liver
Not all liver is created equal when it comes to protein. Beef liver leads the pack, but chicken and pork liver are close behind when you compare them gram for gram. The differences become more obvious at typical serving sizes because those sizes vary quite a bit between animals.
- Beef liver (pan-fried, 81g slice): 21.5g protein
- Chicken liver (pan-fried, one liver, 44g): 11.3g protein
- Pork liver (raw, 28g / 1 oz): 6.1g protein
Chicken livers are small individually, so a typical meal-sized portion of three or four pan-fried chicken livers would put you in the 23 to 34 gram range. Pork liver, scaled up to a comparable cooked portion, lands in a similar neighborhood. The bottom line: whichever type you choose, liver is a reliably high-protein food.
A Complete Protein With Every Essential Amino Acid
Protein quality matters as much as quantity, and liver scores a perfect 100% on the amino acid completeness scale. That means it provides all nine essential amino acids your body can’t make on its own, and in proportions that meet or exceed recommended levels. A single serving of beef liver delivers well over 100% of the recommended daily intake for every essential amino acid, including leucine (important for muscle building), lysine, and tryptophan (a precursor to serotonin).
This makes liver especially useful for people trying to get high-quality protein from smaller portions, whether due to appetite limitations, calorie goals, or simply preferring nutrient-dense foods over larger meals.
How Liver Compares to Common Protein Sources
Beef liver holds its own against mainstream protein sources. A 100-gram cooked portion of beef liver provides roughly 26 grams of protein, which is in the same range as skinless chicken breast (about 31g per 100g cooked) and sirloin steak (about 27g). Where liver stands apart is everything else it brings along: extremely high levels of vitamin A, B12, iron, and copper that you won’t find in comparable amounts in muscle meats.
The trade-off is that liver’s vitamin A content is so concentrated that eating it daily can push you past safe upper limits. A standard serving of about 4 ounces (113 grams) once or twice a week is a common guideline that lets you capture the nutritional benefits without overdoing vitamin A.
Cooking Methods and Protein Retention
Cooking doesn’t destroy the protein in liver. Pan-frying, braising, and baking all preserve the amino acid content effectively. What changes during cooking is the weight of the liver itself: water loss concentrates the nutrients, so cooked liver contains more protein per gram than raw liver. This is why a raw 100-gram portion at 20.3 grams of protein yields a smaller but more protein-dense cooked piece.
Overcooking liver doesn’t reduce its protein value significantly, though it does affect texture and taste. Liver cooked to medium (slightly pink in the center) tends to be more tender and palatable than liver cooked until dry, which can become grainy and bitter.
Getting the Most Protein From Liver
If you’re eating liver primarily for its protein content, a few practical points are worth knowing. Beef liver gives you the most protein per serving simply because the pieces are larger. Chicken livers work well if you prefer a milder flavor, but you’ll need several to match what one slice of beef liver provides. Pâté and liver sausage are popular prepared forms, but these are typically blended with fat, butter, or cream, which dilutes the protein concentration per serving.
Frozen liver retains its nutritional profile well, so buying in bulk and thawing individual portions is a practical way to incorporate it into a weekly routine. Soaking liver in milk for 30 to 60 minutes before cooking can mellow the strong, mineral-heavy taste that turns some people off, without affecting its protein or nutrient content.