Desiccated Beef Spleen

Desiccated beef spleen is a freeze-dried whole-food supplement marketed primarily for its heme iron density (spleen filters and recycles red blood cells, so it contains roughly 45 mg heme iron/100g vs. ~8 mg/100g for liver — about 5x denser) and for tuftsin and splenopentin peptides claimed to support immunity. The iron content claim is biologically plausible — heme iron absorbs at 15–35% vs. 2–20% for non-heme — but no RCTs have evaluated desiccated spleen for iron repletion or anemia. The immune-peptide marketing rests on in-vitro and mid-20th-century animal data, not modern human trials. The 'like supports like' framing (Ancestral Supplements: 'consuming spleen may strengthen and support our own spleen') has no clinical or mechanistic basis — oral consumption of an organ does not deliver intact cells or organ-specific signaling to the corresponding organ in the consumer. Spleen also contributes B12, selenium, and zinc. **Iron overload caution:** the same density that makes spleen attractive for iron-depleted individuals makes it inappropriate for adult men, postmenopausal women, and the ~1:200 of Northern Europeans homozygous for the HFE C282Y hemochromatosis variant — daily heme iron loading in these populations carries real risk. No established RDA/UL.

Limited clinical evidence. No RCTs on desiccated spleen as a supplement or for iron repletion. Immune-peptide claims (tuftsin, splenopentin) rest on in-vitro and animal data, not human trials. Heme iron density poses iron overload risk for hemochromatosis carriers, adult men, and postmenopausal women — daily use not appropriate for iron-replete populations.