Liver extract is a concentrated supplement derived from animal liver — most commonly beef (bovine) or pork (porcine) — that has been dried, hydrolyzed, or processed into a more convenient form. It captures nearly everything present in whole liver: a remarkably dense package of iron, B vitamins, fat-soluble vitamins, amino acids, and trace minerals. Liver has been called 'nature's multivitamin' for good reason — gram for gram, it is one of the most nutrient-complete foods in existence.

The heme iron in liver extract is absorbed significantly more efficiently than plant-based (non-heme) iron, making it particularly effective for correcting or preventing iron-deficiency anemia. The concentrated B12 and folate support red blood cell production and neurological function, while preformed vitamin A (retinol) supports immune health, skin, and vision. Choline and the amino acid profile provide additional support for liver function and cellular repair.

Desiccated (dried) whole liver capsules are the most common modern form and retain the full nutrient profile. Hydrolyzed liver extracts have been pre-broken down for potentially faster absorption. Historical injectable liver extracts (Campothecin-era medicine) were used clinically to treat pernicious anemia before isolated B12 was available. Liquid extracts are also available but less common.

• Iron-deficiency anemia
• Fatigue and low energy
• Vitamin B12 deficiency
• Folate deficiency
• Poor athletic endurance and recovery
• Weak immune function
• Poor skin, hair, and nail health
• Nutritional gaps from restrictive diets
• Liver support and detoxification
• Cognitive fog and focus issues

• Iron-deficiency anemia in high-risk groups (pregnant women, endurance athletes, restrictive dieters)
• Neural tube defects when adequate folate status is maintained before and during early pregnancy
• Vitamin B12 deficiency in populations with limited dietary animal food intake

• Beef liver (whole) — The direct whole-food source — pound for pound the most nutrient-dense food on the planet, delivering all the same heme iron, B12, folate, vitamin A, choline, and copper found in the supplement.
• Chicken liver — Slightly milder in flavor than beef liver and still extremely high in B12, folate, iron, and vitamin A — an excellent whole-food alternative to the supplement.
• Pork liver — One of the highest folate sources of all livers and very rich in B12 and iron — commonly consumed across European and Asian traditional diets.
• Lamb liver — Rich in heme iron, B12, and vitamin A, with a nutritional profile close to beef liver and a somewhat distinctive flavor popular in Middle Eastern and Mediterranean cuisines.
• Liverwurst / Liver pâté — A more palatable way to consume liver — processed liver products still retain significant amounts of iron, B12, and vitamin A, though nutrient density varies by preparation and added ingredients.

• Nausea or digestive upset, especially when taken on an empty stomach
• Constipation or dark stools (from iron content)
• Vitamin A toxicity with chronic high-dose use (headache, nausea, skin changes, liver strain)
• Iron overload in people with hemochromatosis or high baseline iron levels
• Potential gout flare in susceptible individuals due to high purine content
• Theoretical risk of prion exposure if product is not from certified BSE-free herds (extremely rare with quality-sourced products)
• Rare allergic reactions in individuals with meat allergies

• Recommended daily: Typically 3,000–6,000 mg of desiccated whole liver per day (equivalent to roughly 1–2 oz of fresh liver), often split across 3–6 capsules depending on product concentration. Follow label guidance, as nutrient density varies significantly between brands.
• Best time of day: Morning or early afternoon is preferred by most users since the B vitamins and iron can be energizing; some find evening use disrupts sleep.
• With or without food: Best taken with food to reduce nausea and improve iron absorption. Pairing with a small amount of vitamin C-rich food (citrus, bell pepper) may enhance iron absorption further.
• Time to effect: Iron and energy improvements: 2–6 weeks. B12 and folate status normalization: 4–8 weeks of consistent use.
• How long to take it: Can be used continuously as a whole-food supplement for as long as nutritional need persists. Periodic breaks (every 3 months) are a reasonable precaution to avoid cumulative vitamin A excess with very high doses. Monitor iron levels if using long-term, especially in men and post-menopausal women.