Beef Spleen SupplementHeme Iron, Zinc & Immune Peptides

Iron per 100g

~42mg

Highest of any meat

Zinc per 100g

2–3mg

18–27% Daily Value

Vitamin B12 per 100g

~3µg

125% Daily Value

Tuftsin

Present

Immune peptide

Protein per 100g

~19g

Complete amino acid profile

Calories per 100g

~105 kcal

Lean organ tissue

USDA FoodData Central; Hallberg L et al., 1979 — Am J Clin Nutr

Beef spleen contains approximately 42mg iron per 100g — the highest iron content of any organ or muscle meat. The majority is heme iron, absorbed at 15–35% regardless of body iron status. Clinically relevant for iron-deficiency anemia, particularly in premenopausal women.

Nishioka K et al., 1972 — Biochim Biophys Acta; Nathan CF, 1987 — J Exp Med

Tuftsin (Thr-Lys-Pro-Arg) is a naturally occurring peptide found in the spleen's IgG fraction. Laboratory and animal studies demonstrate tuftsin activates phagocytosis in macrophages and neutrophils. Human clinical evidence from whole spleen food products is absent. The 'like supports like' claim for immune support is mechanistically plausible but lacks RCT verification.

Prasad AS, 2008 — J Am Coll Nutr

Beef spleen contains approximately 2–3mg zinc per 100g. Zinc is essential for T-cell function, wound healing, testosterone biosynthesis, and over 300 enzymatic reactions. Dietary zinc from animal sources is more bioavailable than plant zinc (no phytate competition).

Q. Why is beef spleen in organ supplements?

Beef spleen is included in organ supplements for its iron density (second only to liver), zinc content, and naturally occurring immune peptides (tuftsin and splenopentin). The spleen is an iron-storage organ, making spleen tissue exceptionally iron-rich. For women with iron-deficiency anemia or those with heavy menstrual blood loss, the high heme iron content is the primary rationale.

Q. What is tuftsin and does it work?

Tuftsin is a naturally occurring tetrapeptide (Thr-Lys-Pro-Arg) found in spleen tissue. It stimulates macrophage, monocyte, and neutrophil activity in laboratory studies. Clinical evidence for supplemental tuftsin from food-based spleen products is limited — most research involves isolated tuftsin, not whole spleen extracts. The 'like supports like' immune benefit is plausible mechanistically but unproven in RCTs.

Q. Is beef spleen safe for people with iron overload?

No. Spleen is exceptionally iron-dense. For people with hemochromatosis (hereditary iron overload) or elevated ferritin, beef spleen supplements are contraindicated. Heme iron from spleen is absorbed at 15–35% — the body cannot actively reduce heme iron absorption the way it can reduce non-heme iron. Those with iron overload conditions should avoid all organ supplements containing spleen or liver.