Immunoglobulin (IgG) Concentrate
Best-in-class: SBI Protect
Concentrated bovine immunoglobulins that bind microbial antigens in the gut lumen — a barrier-support product with better evidence than most in this category.
Immunoglobulin (IgG) Concentrate quick facts
| Suggested dose | 5–10 g daily, often divided. |
| How often | Daily, divided |
| Who it's for | Diarrhea-predominant IBS, post-infectious gut symptoms, barrier support. |
Real randomized evidence in diarrhea-predominant IBS and in HIV enteropathy, which is a stronger clinical base than most gut supplements have. It is a medical food in some jurisdictions rather than a supplement. Expensive. Bovine-derived, so relevant for anyone with dairy protein concerns, though it is serum rather than milk derived.
How Immunoglobulin (IgG) Concentrate actually works
Serum-derived bovine immunoglobulin binds bacterial antigens, lipopolysaccharide and toxins in the intestinal lumen, preventing them from reaching the epithelium. That reduces the immune activation driving barrier inflammation — it works in the lumen rather than being absorbed, which is why it can act without systemic effects.
Where to get Immunoglobulin (IgG) Concentrate
Find Immunoglobulin (IgG) Concentrate on iHerb →The evidence for Immunoglobulin (IgG) Concentrate
Graded by what exists behind each claim.
✅ Clinically validated
- Randomized and open-label trials show improved stool consistency and reduced symptom burden in diarrhea-predominant IBS and in HIV-associated enteropathy.
- Distinct from colostrum in being standardized for IgG content rather than sold as whole colostrum.
📊 Correlative data
- Bovine colostrum and serum immunoglobulins have long agricultural use, and the human interest came from observing that infants receiving colostrum have measurably better gut barrier outcomes. That is an observation about neonates, and the extrapolation to adults is not established.
🧪 Theoretical / extrapolated benefits
- Binding lipopolysaccharide and other antigens in the lumen is proposed to reduce immune activation at the mucosal surface.
How to read these tiers: they say how much human evidence exists, not how well something works — and ✗ flags harm, never a disappointing trial. How the evidence tiers work →
What Immunoglobulin (IgG) Concentrate actually does
This is bovine plasma, purified. Serum-derived bovine immunoglobulin is a protein isolate in which immunoglobulin G is the major component, alongside IgA, IgM and other serum proteins, standardized to an IgG content rather than sold as whole colostrum. It is regulated as a medical food, which is a different category from a supplement, and the distinction is not marketing: it exists because the intended use is the dietary management of a disease.
The mechanism is binding, in the lumen, and nothing more. An IgG molecule has two antigen-binding arms. Swallowed in grams, it encounters bacterial lipopolysaccharide and other microbial antigens in the gut contents and binds them; the resulting complex is too large to cross and is carried onward and out. Less antigen reaching the epithelium means less activation of the mucosal immune system, and less activation means less of the cytokine-driven secretion and hypersensitivity that produce the symptoms Petschow 2014. Nothing in that chain requires the antibody to be absorbed. It works precisely because it is not.
And it is definitely not absorbed, which was measured. Forty-two healthy adults took single doses of 5, 10 or 20 g and then twice-daily dosing for two weeks; what rose in plasma was the area under the curve for essential and total amino acids, significantly above placebo at every dose (P < 0.05) Shaw 2016. That is the signature of a protein being digested into its parts, not of an antibody entering the circulation. A large fraction of what you swallow is being eaten as food, and the therapeutic fraction is whatever manages to bind an antigen before pepsin and the pancreatic proteases reach it.
Two named human read-outs show the barrier mechanism doing something. In 103 people with HIV and chronic diarrhea, this powder lowered circulating I-FABP by 0.35 ng/µL (P = 0.002) — the enterocyte injury marker — and zonulin by 4.90 ng/µL (P = 0.003), zonulin being the regulator of intercellular tight junctions. Interleukin 6 fell by 0.40 pg/µL (P = 0.002) and CD4+ T cells rose by 26 cells/µL (P = 0.002) Utay 2019. Damage marker down, junction regulator down, inflammatory cytokine down, immune reconstitution up. That is a coherent set, and it is rare in this half of the shelf.
This is not colostrum, and the difference is arithmetic. Colostrum is milk from the first days of lactation: IgG plus growth factors plus lactose plus casein, rarely standardized. A colostrum capsule declaring 25% IgG at a 1 g serving delivers about 250 mg of antibody. A serum-derived isolate at 10 g a day, with IgG as its major component, delivers grams. Twenty times the antibody is not a refinement of the same product; it is a different intervention wearing a similar word.
Cell, rodent, human — and where it stops
The mechanistic tier is binding chemistry and it is unglamorous. The proposed action — luminal antigen capture reducing mucosal immune activation — has been assembled from preclinical binding work and reviewed as a postulated mechanism rather than proven end to end Petschow 2014. Calling it postulated is the authors' own word and it is the right one.
The first human step used biopsies, not questionnaires. Eight patients with HIV enteropathy took 2.5 g twice daily for eight weeks with a nine-month extension. Mucosal CD4 lymphocyte density rose by a median of 139.5 cells/mm2, from 213 to 322 (P = 0.016); D-xylose absorption improved in seven of the eight; and bowel movements per day fell (P = 0.008) Asmuth 2013. A duodenal biopsy and a sugar absorption test are objective in a way a symptom diary is not, and this is the strongest thing in this product's file.
The second human step scaled it up. One hundred and three people with HIV on suppressive therapy and chronic diarrhea were randomized to 2.5 or 5 g twice daily, four weeks blinded plus a 20-week extension, producing the I-FABP, zonulin, IL-6 and CD4 numbers above Utay 2019. Twenty-four weeks is a long exposure by this category's standards.
The gut-symptom trials are smaller and softer, and the page should say which is which. Thirty people with diarrhea-predominant irritable bowel syndrome took 5 or 10 g/day for six weeks, 15 per arm. At 10 g/day, abdominal pain (P < 0.01), loose stools (P < 0.01), bloating (P < 0.05) and flatulence (P < 0.01) improved; at 5 g/day, flatulence (P < 0.035) and incomplete evacuation (P < 0.05) Wilson 2013. Those are within-group changes over time in fifteen people per arm, which is a weaker statement than a difference against placebo. And in inflammatory bowel disease the evidence is a retrospective chart review of 45 patients on 5 g/day for 12 weeks, reporting a 2.8-fold likelihood of clinical improvement (95% CI 1.266–6.016, P = 0.011) with response rising from 49% at week 1 to 76% at week 12 Shafran 2015 — a chart review, not a trial.
The obstacle is the population, and it is unusually easy to state. Every objective endpoint on this page belongs to people with a documented enteropathy: measurable epithelial injury, measurable immune activation, measurable malabsorption Asmuth 2013 Utay 2019. A reader with bloating and no diagnosis has none of those abnormalities to correct. The mechanism predicts benefit in proportion to how much antigen is getting through, and in a person whose barrier is intact the answer is not much.
The dose, unusually, is the one thing that lines up. The 5–10 g a day on this site's card is the range the trials used Wilson 2013 Asmuth 2013 Utay 2019, and 10 g is the arm where most endpoints moved. That is worth saying out loud because on most of this shelf it is the opposite.
Immunoglobulin (IgG) Concentrate — which form, and does it matter
Serum-derived and colostrum-derived are different raw materials. This product starts from bovine plasma and is purified to a protein isolate with IgG as its major component; colostrum starts from milk. Every trial cited on this page used the serum-derived isolate Wilson 2013 Asmuth 2013 Utay 2019 Shafran 2015, and colostrum's evidence is a separate and much softer file that frequently gets quoted as though it belonged here.
Grams of IgG is the unit, so read the percentage and multiply. A 10 g serving of an isolate that is roughly half immunoglobulin delivers about 5 g of antibody. Any product that declines to state an IgG percentage cannot be compared with the trials at all, because the trial dose was defined by the isolate, not by scoop volume Wilson 2013.
It is a protein, so treat it like one in the kitchen. Immunoglobulin is a folded protein held together by disulfide bonds and hydrogen bonding; heat denatures it and denatured antibody has lost its binding site. Stirring the powder into hot coffee is not a neutral convenience. Cold or room-temperature water, mixed and drunk, is what the trials did.
The medical-food category tells you something about the evidence. A medical food is intended for the dietary management of a disease under medical supervision. That is why the strongest studies here are in HIV enteropathy and inflammatory bowel disease rather than in wellness populations Asmuth 2013 Shafran 2015, and it is why the same powder retailed as a general gut-health supplement is being sold outside the setting its own evidence was generated in.
What would have to be true, and how you would know it was not
1. Bowel output is the target, and 10 g is the arm to run. Predict a fall in urgent days per week and a firming of stool form over four to eight weeks at 10 g/day — the dose where pain, loose stools, bloating and flatulence all moved Wilson 2013, and the shape of the change reported when bowel movements per day fell in enteropathy Asmuth 2013. Below 5 g/day you are running a dose nobody has studied.
2. The prediction that cuts against the product. Predict hs-crp does not move in anyone without a documented enteropathy. The inflammatory result on record is interleukin 6 falling by 0.40 pg/µL in people with HIV and chronic diarrhea Utay 2019 — a research assay, in a population with measurable immune activation to begin with. Predict cbc unchanged. A marker with nothing wrong with it cannot improve, and that is most readers.
3. Predict your own antibody levels do not change, because you are eating protein. What rose in plasma after a dose was amino acids, not immunoglobulin Shaw 2016. So predict serum IgG, IgA and any immune panel are exactly where they were. If somebody tells you this raises your antibodies, that is the one claim the pharmacokinetic study directly refutes.
4. In genuine malabsorption, the nutritional markers are the delayed confirmation. D-xylose absorption improved in seven of eight enteropathy patients Asmuth 2013, so predict that in someone with real absorptive failure, albumin on the cmp and ferritin drift upward over three to six months — and predict flat lines in someone whose baseline nutrition was normal. What will fool you is that a 10 g daily protein isolate is also 40 calories and a diet change, and post-infectious gut symptoms improve on their own over exactly this window.
What nobody has tested yet
Nobody has run this in post-infectious gut symptoms, which is half of who buys it. The randomized evidence sits in HIV enteropathy Utay 2019 and in diarrhea-predominant irritable bowel syndrome at n = 30 Wilson 2013. A trial in people recovering from a documented enteric infection, with I-FABP and zonulin as endpoints rather than a diary, is the obvious study and it does not exist.
Nobody has measured how much intact antibody reaches the colon. The mechanism is luminal binding Petschow 2014 and the pharmacokinetic study measured what appeared in blood Shaw 2016. What has never been published is the fraction of swallowed IgG recoverable, still functional, in ileal or fecal contents — the one number that would say whether grams are necessary or whether hundreds of milligrams would do.
Nobody has gone above 10 g for a gut endpoint, although the safety data reach 20. Twenty grams a day was tolerated in healthy adults Shaw 2016, and the symptom trial stopped at 10 with the higher arm outperforming the lower Wilson 2013. A dose above the one where the curve was still rising has never been tried, which is an unusual place for a literature to stop.
And nobody has run it against colostrum at matched IgG. That trial would settle whether the serum origin matters or whether the antibody dose is the whole story — and it would decide whether a product costing several times as much per gram is buying anything but purity.
Immunoglobulin (IgG) Concentrate — its own safety story, not its category's
This is a bovine blood-derived product, and that is the sourcing question rather than dairy. It contains no casein and no lactose, so a milk allergy is not the relevant concern; a bovine protein sensitivity is, and so is anyone whose objection to animal products is categorical. Plasma-derived material also carries a sourcing and screening chain that a plant extract does not, and a manufacturer that will not describe it is telling you something.
The tolerability ceiling is documented, and it is high. Single doses of 5, 10 and 20 g and two weeks of twice-daily dosing were safe in 42 healthy adults, up to 20 g/day Shaw 2016, and 24 weeks of exposure was tolerated in 103 people with HIV Utay 2019. That is a better-defined safety envelope than almost anything else in this category, and it is worth saying plainly rather than hedging.
The interaction nobody lists is the protein load itself. Ten grams a day of a purified protein isolate is ten grams of extra dietary protein. In advanced chronic kidney disease, where protein intake is prescribed rather than assumed, that is a number that belongs in the conversation with the renal dietitian, and it appears on no label because nobody thinks of a gut-barrier powder as food.
The real harm here is substitution, not toxicity. The inflammatory bowel disease evidence is a retrospective review of 45 patients using it alongside conventional therapy, not instead of it Shafran 2015. It is an adjunct in every study it appears in. The way this product hurts somebody is by feeling expensive and serious enough to justify tapering the drug that was actually controlling the disease.
Sources read for this page
- Petschow BW. Serum-derived bovine immunoglobulin/protein isolate: postulated mechanism of action for management of enteropathy.. Clin Exp Gastroenterol 2014 · PMID 24904221
- Asmuth DM. Oral serum-derived bovine immunoglobulin improves duodenal immune reconstitution and absorption function in patients with HIV enteropathy.. AIDS 2013 · PMID 23660579
- Utay NS. Serum Bovine Immunoglobulins Improve Inflammation and Gut Barrier Function in Persons with HIV and Enteropathy on Suppressive ART.. Pathog Immun 2019 · PMID 31139758
- Wilson D. Evaluation of serum-derived bovine immunoglobulin protein isolate in subjects with diarrhea-predominant irritable bowel syndrome.. Clin Med Insights Gastroenterol 2013 · PMID 24833942
- Shafran I. Management of inflammatory bowel disease with oral serum-derived bovine immunoglobulin.. Therap Adv Gastroenterol 2015 · PMID 26557889
- Shaw AL. Absorption and safety of serum-derived bovine immunoglobulin/protein isolate in healthy adults.. Clin Exp Gastroenterol 2016 · PMID 27980432
How you would know if it worked
There is no blood test for this one. That is not a criticism — it is a fact about the effect, and it changes how you should judge it.
- What to watch: Stool consistency and urgent days per week in diarrhea-predominant IBS or after a gut infection — the populations where the randomized and open-label trials reported benefit. This binds antigens in the lumen, so bowel output is the target rather than any sensation higher up.
- How long before it means anything: Four to eight weeks at five to ten grams daily. It is expensive relative to everything else in this category, so decide in advance what a fair test costs and stop at that number instead of drifting.
- What will fool you: Post-infectious gut symptoms improve on their own over months, which is precisely the window in which people try this, so the recovery curve gets credited to the powder. The colostrum evidence often cited alongside it is an observation about neonatal gut barrier, and the extension to adults is not established.
Run it one variable at a time. Starting three things in one week means a result you cannot attribute, which is the same as no result.
Immunoglobulin (IgG) Concentrate — safety & side effects
- GI upset and bloating.
- Bovine serum-derived — a consideration for allergy and for dietary restriction.
- Generally well tolerated in the trials. No established drug interactions.
Not medical advice. If you take prescription medication or have a diagnosed condition, check this against it with a pharmacist or doctor — pharmacists are underused and free.
- When to take it, and what to take it with
- Which form actually absorbs
- Who it's worth it for
- Best-in-class brand pick
- Coach Cam's stacks and notes
- Fasted or with food, and when in the day
- Morning or night, and why that window
- Around training, or deliberately away from it
- What it must not share a window with
Everything above is free and stays free. Skool is where it becomes a plan — Immunoglobulin (IgG) Concentrate in an order, with the rest of what you're running.
Unlock in Skool — $10/mo →Bloodwork to run alongside Immunoglobulin (IgG) Concentrate
Baseline first, then again at 8–12 weeks.
| Marker | What it’s watching for |
|---|---|
| Complete Blood Count (CBC) with Differential | Anemia is the commonest sign of a gut absorbing badly |
| Ferritin | Iron is the first thing malabsorption takes |
| Vitamin B12 | The second thing, and the one with permanent consequences |
| hs-CRP (High-Sensitivity C-Reactive Protein) | Separates inflammatory bowel disease from IBS |
The Gut Health & Absorption panel covers these in one order — 11 markers, $208.80 with the discount applied.
Check results you already have → · All 103 markers A–Z
Immunoglobulin (IgG) Concentrate — frequently asked questions
What is Immunoglobulin (IgG) Concentrate?
Concentrated bovine immunoglobulins that bind microbial antigens in the gut lumen — a barrier-support product with better evidence than most in this category.
What is the suggested dose of Immunoglobulin (IgG) Concentrate?
5–10 g daily, often divided. This is a general reference for education only — statements have not been evaluated by the FDA and this is not medical advice.
Where can I find Immunoglobulin (IgG) Concentrate dosing and the full breakdown?
The suggested dose and the full evidence — clinical, correlative and theoretical — are on this page. What's inside Skool is when to take it, which form actually absorbs, the brand worth buying and Coach Cam's stacks.
Where can I buy Immunoglobulin (IgG) Concentrate?
Coach Cam sources Immunoglobulin (IgG) Concentrate from vetted, top-rated brands on iHerb — use the buy link on this page.
What Immunoglobulin (IgG) Concentrate is used for
Immunoglobulin (IgG) Concentrate appears under 3 goals in the goal router.
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Where this goes next
The pages here are the frameworks. The protocols — the dosing, the order to correct things in, the week-by-week schedule and what to retest — are inside Skool.