Liver is one of the most protein-dense foods you can eat. A 100-gram serving of raw beef liver contains about 20 grams of protein, and that number climbs to roughly 26 grams per 100 grams once it’s cooked, since water evaporates during the process. That puts it on par with chicken breast and lean steak, but liver packs far more vitamins and minerals per calorie than either.
Protein by Type of Liver
Different animal livers deliver slightly different amounts of protein, though they’re all in the same ballpark. Beef liver provides around 20 grams of protein per 100 grams raw. Pork liver comes in a bit higher at 26 grams per 100 grams when braised, with only 165 calories and 4.4 grams of fat. Chicken liver lands in a similar range: a full batch cooked down from 400 grams of raw liver yields about 63 grams of protein total, which works out to roughly 24 to 26 grams per 100-gram cooked portion.
For a typical 3-ounce (85-gram) cooked serving, you can expect somewhere between 22 and 26 grams of protein regardless of which animal the liver comes from. That’s a meaningful chunk of the 50 to 60 grams most adults need daily.
Liver Is a Complete Protein
Not all protein sources contain every amino acid your body needs. Liver does. It scores a perfect 100% on the amino acid completeness scale, meaning it supplies all nine essential amino acids in adequate proportions. A single pan-fried serving of beef liver (about 166 grams) delivers 3,745 milligrams of leucine, the amino acid most directly involved in triggering muscle repair and growth. It also provides strong amounts of lysine (2,833 mg), valine (2,495 mg), and isoleucine (1,934 mg) in that same serving.
This makes liver especially useful if you’re trying to build or maintain muscle. The protein quality rivals whey and eggs, two of the highest-rated sources available.
What Else Comes With the Protein
The real reason liver stands out isn’t just its protein content. It’s what you get alongside that protein. A 3-ounce serving of pan-fried beef liver contains 6,582 micrograms of preformed vitamin A, which is 731% of the daily value. It’s also one of the richest natural sources of vitamin B12 and iron, two nutrients many people fall short on.
This nutrient density is why liver is often called a superfood. Ounce for ounce, few other foods deliver this combination of high-quality protein, B vitamins, iron, and vitamin A in a single low-calorie package. Pork liver, at 165 calories per 100 grams, is particularly lean.
How Liver Compares to Other High-Protein Foods
- Beef liver (cooked): ~26 g protein per 100 g, with exceptionally high vitamin A, B12, and iron
- Chicken breast (cooked): ~31 g protein per 100 g, but far fewer micronutrients
- Eggs: ~13 g protein per 100 g, also a complete protein but less protein-dense
- Ground beef (cooked, 85% lean): ~26 g protein per 100 g, higher in fat and calories than liver
Liver slightly trails chicken breast in pure protein content, but it delivers a broader nutritional profile. If you’re choosing foods based on total nutrient value per serving rather than protein grams alone, liver is hard to beat.
How Often You Can Safely Eat Liver
The vitamin A in liver is preformed, meaning your body absorbs it immediately rather than converting it from plant pigments. That’s a benefit in moderate amounts but a potential problem in excess. The tolerable upper limit for preformed vitamin A in adults is 3,000 micrograms per day. A single 3-ounce serving of beef liver contains more than double that at 6,582 micrograms.
Occasional servings are fine for most adults. Eating liver once or twice a week gives you a reliable protein and nutrient boost without pushing vitamin A intake into risky territory over time. Chronic overconsumption can cause dry skin, joint pain, fatigue, and abnormal liver function. Pregnant women should be particularly cautious, as excess preformed vitamin A is linked to birth defects.
If you enjoy liver regularly, spacing your servings across the week and keeping portions to about 3 ounces is a practical approach that lets you benefit from the protein and nutrients without overdoing the vitamin A.