immunoglobulin

ProteinProteinBest with a meal

What is it

Immunoglobulin (antibody) is a Y-shaped protein produced by the immune system. In supplements, immunoglobulins are usually concentrated from bovine serum or colostrum to provide oral antibody activity in the gut.

Evidence for 2 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Chronic loose stools (IBS-D, HIV enteropathy)

Good Evidence

Serum-derived bovine immunoglobulin is FDA-regulated as medical food for chronic loose stools and has trial support in IBS-D and HIV-associated enteropathy at 5 to 10 g/day.

Gut barrier support

Limited Evidence

Animal studies and limited human data suggest immunoglobulins may bind lipopolysaccharide and reduce intestinal permeability markers.

How it works

Oral immunoglobulin supplements work primarily in the lumen of the small intestine, where antibodies bind bacterial toxins (lipopolysaccharide), pathogenic bacteria, and viral particles. Because immunoglobulins are proteins, they are largely digested before reaching the bloodstream, so their effects are local rather than systemic. The main supplemental form is serum-derived bovine immunoglobulin (SBI), a powder containing more than 50 percent IgG plus other proteins. SBI is also sold as a medical food (EnteraGam) for management of chronic loose stools in HIV-associated diarrhea and IBS-D. Bovine colostrum contains immunoglobulins alongside growth factors, lactoferrin, and oligosaccharides at lower IgG concentrations than purified SBI.

Dosage

Serum-derived bovine immunoglobulin: 2.5 to 10 g/day. Colostrum: 10 to 20 g/day to deliver a similar amount of IgG. Effects on diarrhea typically appear within 1 to 2 weeks of consistent use.

When and how to take it

Take immunoglobulin powders or capsules with meals to maximize binding to gut antigens during digestion. Split daily dose across 2 or 3 meals. Consistent use over at least 2 weeks needed to assess GI effect.

2 commercial forms

Compare the main delivery options and what they’re best suited for.

Serum-derived bovine immunoglobulin (SBI)

Powder mixed in water; medical food brand EnteraGam is the regulated form.

Greater than 50 percent IgG; works locally in gut.

Bovine colostrum

Powder, capsule, or chewable. IgG content varies by source.

Lower IgG concentration but includes growth factors and lactoferrin.

Safety

Generally well tolerated. Mild gas, bloating, or constipation reported. Not suitable for people with milk allergy (colostrum) or bovine plasma allergy.

Who should be cautious

People with bovine protein allergy should avoid. Pregnant and breastfeeding women have limited data; vegans cannot use animal-derived products.

Interactions

No significant drug interactions reported. Theoretically, immunoglobulins might bind some oral medications; separate other oral medications by 1 to 2 hours if concerned.

Food sources

Bovine colostrum

Amount
10 g
%DV
—

Human breast milk (especially colostrum)

Amount
100 mL
%DV
—

Frequently asked questions

Do oral immunoglobulins get absorbed into my blood?⌄

No, not in adults. They work locally in the gut. Newborns can absorb some immunoglobulins from breast milk for the first day or two.

Is SBI the same as colostrum?⌄

Both contain bovine IgG, but SBI is purified from bovine serum and has higher IgG concentration. Colostrum also contains other bioactive proteins.

References

immunoglobulin on Wikidata — Wikidata link

immunoglobulin on NIH DSLD (US supplement label database) — NIH Dietary Supplement Label Database link

Research on immunoglobulin (PubMed search) — PubMed link

Track immunoglobulin with Pilora

Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.

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Evidence-based·How we grade evidence

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.