Home Ingredients Beef Spleen (Desiccated)
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Beef Spleen (Desiccated)

Evidence Level
Preliminary
3 Clinical Trials
6 Documented Benefits
1/5 Evidence Score

Beef spleen is one of the most iron-dense foods: USDA data list raw beef spleen at 44.6 mg of iron per 100 g, several times the iron in beef liver, and in an analysis of calf organs about 73% of spleen iron was heme iron. The spleen breaks down old red blood cells, which is why its tissue holds so much iron. It also contains vitamin B12 and selenium in modest amounts, copper only in traces, and immune-related peptides. Desiccated beef spleen capsules typically deliver 1.5-3 g/day. Drying removes about three quarters of the weight as water, so that is roughly 7 to 13 g of fresh spleen, which on USDA figures supplies about 3 to 6 mg of iron a day. That is a real but small amount. A single standard ferrous sulfate tablet contains 65 mg of elemental iron, 10 to 20 times more, so spleen capsules cannot replace treatment for diagnosed iron deficiency. Iron content also varies widely between animals: a Korean analysis found about 123 mg per 100 g in Hanwoo cattle spleen, nearly three times the USDA value, so check whether a label states iron per serving. No trial has tested desiccated spleen in people for iron status, immunity, energy or any other outcome. In two randomized trials comparing a heme iron supplement with ferrous sulfate (in anemic infants and in dialysis patients), heme iron did not improve the main iron measures more and caused no fewer side effects. Spleen is linked to immune-related peptides, but the only human studies of spleen peptides used purified medicines given to hospital patients, not dried spleen. Quality varies by source, so choose products from inspected cattle that state their country of origin.

Studied Dose No human trial has studied a dose. Labels typically suggest 1.5-3 g/day of dried spleen (2-4 capsules at 750 mg), roughly 3-6 mg of iron on USDA figures.
Active Compound Iron, about 73% of it heme iron (USDA lists 44.6 mg total iron per 100 g raw spleen, roughly 2 mg per gram of dried powder), plus vitamin B12, selenium and trace copper.

Benefits

An iron-dense food, but a small daily amount

Raw beef spleen contains about 44.6 mg of iron per 100 g (USDA), and about 73% of spleen iron is heme iron, the form the gut absorbs most efficiently. The rest is largely storage iron (ferritin), which was poorly absorbed in a human isotope study. At 1.5-3 g/day of dried powder, spleen supplies roughly 3-6 mg of iron: about a sixth to a third of the 18 mg daily need of a woman aged 19-50, and a third to three quarters of a man's 8 mg. That is not enough to correct diagnosed iron deficiency, and no trial has measured iron status in people taking spleen capsules.

Supported by Trial 1, Trial 3

Not a substitute for iron treatment

Heme iron is often described as gentler than ferrous sulfate, but two randomized trials comparing them did not find it. In a 2025 trial, 208 anemic infants in The Gambia given 10 mg of iron daily for 84 days as either heme iron polypeptide or ferrous sulfate had the same gains in hemoglobin and ferritin and no difference in adverse events. A 6-month trial in 62 adults on peritoneal dialysis found no efficacy or safety advantage for heme iron polypeptide, and serum ferritin ended lower in the heme iron group. Any stomach upset from spleen capsules is likely to be small simply because they contain little iron. If you have been diagnosed with iron deficiency, spleen capsules do not replace the treatment your doctor recommends.

Supported by Trial 2

A modest amount of vitamin B12

USDA lists raw beef spleen at 5.68 mcg of vitamin B12 per 100 g. At 1.5-3 g/day of dried powder, that works out to roughly 0.4-0.75 mcg, about 15-30% of the 2.4 mcg adult daily need, assuming none is lost in drying. That is a modest contribution and far below the doses used to correct B12 deficiency.

Supported by Trial 1

Copper: trace amounts only

Copper is needed to use iron, but spleen contains very little. USDA lists raw beef spleen at 0.168 mg of copper per 100 g, so 1.5-3 g/day of dried powder supplies about 0.01-0.02 mg, 1-2% of the 0.9 mg adult daily need. Beef liver, not spleen, is the copper-rich organ.

Supported by Trial 1, Trial 2

Traditional 'blood-building' use (context, not evidence)

Spleen and other blood-rich organs have been eaten in several food traditions as a way to 'build blood'. Spleen's iron content makes that tradition understandable, but traditional use is not evidence that spleen capsules improve anemia, and no trial has tested it.

Supported by Trial 3

Immune-related peptides: untested in spleen capsules

Spleen is linked to several immune peptides. Tuftsin is released from antibodies with the help of a spleen enzyme, and splenopentin is a laboratory-made fragment of the spleen protein splenin; both have shown immune effects in laboratory and animal research. Purified spleen peptide medicines have been tested in hospital patients, but these are concentrated drug extracts, not dried spleen. No study has shown that active peptides survive drying and digestion, and no human trial has measured an immune outcome in people taking desiccated spleen.

Supported by Trial 1, Trial 3

Mechanism of action

1

Heme iron absorption pathway

Heme iron is taken up intact by intestinal cells and absorbed more efficiently than non-heme iron from food. The transporter is not fully settled: HCP1, first proposed as the heme carrier, turned out to be mainly a folate transporter. Heme iron absorption is less affected by phytates and polyphenols, although calcium reduces absorption of both forms. Better absorption does not by itself mean fewer side effects: trials comparing a heme iron supplement with ferrous sulfate found no difference in adverse events.

2

Iron and B12 for red blood cells (small amounts)

Iron and vitamin B12 are both needed to make red blood cells, and spleen contains both. At capsule doses the amounts are small (roughly 3-6 mg of iron and under 1 mcg of B12 a day), and copper is present only in traces. No study has measured red blood cell production in people taking spleen.

3

Theoretical immune peptide effects

Tuftsin and splenopentin (a laboratory-made fragment of the spleen protein splenin) have shown immune effects in laboratory and animal research. Purified spleen peptide medicines have been tested in patients, but there is no evidence that eating desiccated spleen delivers active amounts of immune peptides.

Clinical trials

1
Evidence note, not a study: no human trials of desiccated spleen exist

No published human trial of desiccated beef spleen has been found for iron status, immune function, energy or any other outcome.

Not a study of spleen in people.

No published human trial of desiccated beef spleen has been found for iron status, immune function, energy or any other outcome.

2
Background, not a spleen trial: heme iron supplements vs ferrous sulfate
PubMed

Randomized trials have compared heme iron polypeptide, a heme iron supplement, with ferrous sulfate. These trials did not use spleen.

Not a study of spleen in people.

Randomized trials have compared heme iron polypeptide, a heme iron supplement, with ferrous sulfate. These trials did not use spleen. In 208 anemic Gambian infants (10 mg iron daily for 84 days), heme iron polypeptide raised hemoglobin and ferritin no more than ferrous sulfate, with no difference in adverse events. In 62 adults on peritoneal dialysis, it gave no efficacy or safety advantage over 6 months. Both populations differ greatly from a typical supplement buyer.

3
Traditional use (not a trial)

Spleen and other blood-rich organs have been eaten as 'blood-building' foods in several food traditions.

Not a study of spleen in people.

Spleen and other blood-rich organs have been eaten as 'blood-building' foods in several food traditions. Spleen's iron content explains why the tradition arose, but traditional use is not evidence that spleen capsules improve iron status, and no study has tested it.

Side effects and drug interactions

Common Potential side effects

Do not take if you have hemochromatosis or another iron-overload condition. Most spleen iron is heme iron, and the body reduces heme iron absorption less than non-heme iron absorption when iron stores are already high.
Iron content is not standardized and differed about fourfold between published analyses (31 to 123 mg per 100 g of fresh spleen), so iron per capsule is uncertain unless the label states it. Mild stomach upset is possible.
No human trial has assessed the safety of spleen capsules; spleen itself is an ordinary food.
Organ meats are purine-rich foods. People with gout or high uric acid should count spleen toward their purine intake, although a few grams of powder is a small amount.
Bovine spleen is not classed as a BSE specified risk material under US rules (21 CFR 189.5) or EU rules, where spleen is a risk material only in sheep and goats. US rules bar specified risk materials and material from uninspected or non-ambulatory cattle from dietary supplements, so choose products that state their country of origin and use inspected cattle.
Iron-containing products are a leading cause of fatal poisoning in children under 6; keep out of reach.
If you are pregnant or breastfeeding, check iron needs with your doctor rather than self-dosing.
Do not take supplemental iron without knowing your iron status; excess iron accumulates and can cause harm.

Important Drug interactions

Iron supplements: spleen adds a few milligrams of iron a day. People taking prescribed iron or with high ferritin should tell their doctor.
Calcium supplements and calcium-rich foods: taken at the same meal, calcium reduces absorption of both heme and non-heme iron.
Levothyroxine: iron can reduce thyroid hormone absorption, so take them at least 4 hours apart.
Generally minimal interactions with most common medications.
Consult healthcare providers when combining with iron-modifying treatments.

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Frequently asked questions about Beef Spleen (Desiccated)

What is beef spleen supplement used for?

Desiccated beef spleen is dried, powdered spleen sold in capsules, mainly as a food source of iron. A typical 1.5-3 g daily serving supplies roughly 3-6 mg of iron. It has never been tested in a human trial, and its immune claims rest on peptides with no evidence of activity when eaten.

What is beef spleen good for?

Its one established property is its iron content, most of it well-absorbed heme iron. But capsule amounts are small, and no trial has shown that spleen capsules improve iron status, energy or immunity. There are no human trials of spleen capsules at all, not just no large ones.

How much beef spleen should I take?

No dose has been tested in people. Labels typically suggest 1.5-3 g of dried spleen a day, roughly 3-6 mg of iron. If you have iron deficiency, get a treatment dose from your doctor: spleen capsules supply only a small fraction of it.

Is beef spleen safe?

Spleen is an ordinary food, but capsules have not been studied for safety. Do not take it if you have hemochromatosis or another iron-overload condition. Keep iron-containing products away from children, and check your iron status before adding iron. People with gout should count it toward their purine intake.

What is Beef Spleen?

Beef spleen is one of the most iron-dense foods: USDA data list raw beef spleen at 44.6 mg of iron per 100 g, several times the iron in beef liver, and in an analysis of calf organs about 73% of spleen iron was heme iron. The spleen breaks down old red blood cells, which is why its tissue holds so much iron.

What is Beef Spleen used for?

Beef Spleen is researched primarily for Energy. Raw beef spleen contains about 44.6 mg of iron per 100 g (USDA), and about 73% of spleen iron is heme iron, the form the gut absorbs most efficiently.

What is the recommended dosage of Beef Spleen?

The clinically studied dose is No human trial has studied a dose. Labels typically suggest 1.5-3 g/day of dried spleen (2-4 capsules at 750 mg), roughly 3-6 mg of iron on USDA figures. Always follow the product label and check with a healthcare provider for personal advice.

Is Beef Spleen safe, and does it have side effects?

For most healthy adults, Beef Spleen is well tolerated at studied doses. Reported effects can include: Do not take if you have hemochromatosis or another iron-overload condition. Most spleen iron is heme iron, and the body reduces heme iron absorption less than non-heme iron absorption when iron stores are already high. It may also interact with some medications. Beef Spleen is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Does Beef Spleen interact with any medications?

Possible interactions include: Iron supplements: spleen adds a few milligrams of iron a day. People taking prescribed iron or with high ferritin should tell their doctor. Calcium supplements and calcium-rich foods: taken at the same meal, calcium reduces absorption of both heme and non-heme iron. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for Beef Spleen?

NutraSmarts rates the evidence for Beef Spleen as Preliminary (1 out of 5). It is backed by 3 clinical trials and 6 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(6 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Seong PN, Kang GH, Park KM, Cho SH, Kang SM, Park BY, Moon SS, Ba HV Characterization of Hanwoo Bovine By-products by Means of Yield, Physicochemical and Nutritional Compositions Korean Journal of Food Science and Animal Resources. 2014;34(4):434-47. doi:10.5851/kosfa.2014.34.4.434.PubMedUsed to support: Analysis of Hanwoo (Korean) cattle by-products. Spleen had the highest iron content of all by-products tested, 1,233 mg/kg (about 123 mg per 100 g), while liver had the highest copper and spleen copper was low (2.01 mg/kg). This is a food-composition study that measured total iron, not heme iron, and did not study people taking spleen.
  2. Xing Y, Gao S, Zhang X, Zang J Dietary Heme-Containing Proteins: Structures, Applications, and Challenges Foods. 2022;11(22):3594. doi:10.3390/foods11223594.PubMedUsed to support: Narrative review of hemoglobin, myoglobin and other heme proteins as dietary iron sources, describing their higher absorption than non-heme iron and their use in iron fortification. It does not examine spleen or report trials of spleen supplements.
  3. Valenzuela C, de Romaña DL, Olivares M, Morales MS, Pizarro F Total iron and heme iron content and their distribution in beef meat and viscera Biological Trace Element Research. 2009;132(1-3):103-11. doi:10.1007/s12011-009-8400-3.PubMedUsed to support: In tissue from two 4-month-old calves, spleen contained 31.2 mg of iron per 100 g, the most of any organ tested (liver 6.0 mg), and 72.8% of spleen iron was heme iron. A food-composition analysis in two animals, not a study of people eating spleen.
  4. Skikne B, Fonzo D, Lynch SR, Cook JD Bovine ferritin iron bioavailability in man European Journal of Clinical Investigation. 1997;27(3):228-33. doi:10.1046/j.1365-2362.1997.970645.x.PubMedUsed to support: In 10 people given radiolabelled ferritin iron isolated from bovine spleen and liver, absorption from a 5 mg dose averaged 3.8% fasting, against 24.1% for the same dose as ferrous sulphate, and spleen ferritin was absorbed no better than liver ferritin. Shows that ferritin, a storage form of iron found in spleen, is poorly absorbed; isolated ferritin was tested, not whole spleen.
  5. Bah M, Verhoef H, Okoh E, Bah A, Colley A, Saidykhan A, Prentice AM, Cerami C Heme iron compared with ferrous iron salts to treat iron deficiency anemia in Gambian children: a randomized controlled trial The American Journal of Clinical Nutrition. 2025;122(4):997-1005. doi:10.1016/j.ajcnut.2025.07.037.PubMedUsed to support: Randomized trial in 208 anemic Gambian infants aged 6-12 months given 10 mg of iron daily for 84 days. Heme iron polypeptide and ferrous sulfate raised hemoglobin and ferritin equally (the primary outcomes), with no difference in adverse events, although heme iron improved several secondary iron markers. It tested a heme iron supplement, not spleen, in a population very different from adult supplement buyers.
  6. Barraclough KA, Brown F, Hawley CM, Leary D, Noble E, Campbell SB, Isbel NM, Mudge DW, van Eps CL, Johnson DW A randomized controlled trial of oral heme iron polypeptide versus oral iron supplementation for the treatment of anaemia in peritoneal dialysis patients: HEMATOCRIT trial Nephrology Dialysis Transplantation. 2012;27(11):4146-53. doi:10.1093/ndt/gfs372.PubMedUsed to support: Randomized trial in 62 adults on peritoneal dialysis. Six months of heme iron polypeptide did not raise transferrin saturation more than ferrous sulphate, serum ferritin ended lower, and there was no safety advantage. It tested a heme iron supplement, not spleen, in kidney patients.