Colostrum: what is it, its properties, and is it worth supplementing beyond infancy?

Colostrum (first milk) is the first secretion of the mammary glands right after birth – a concentrated mixture of immunoglobulins, growth factors, lactoferrin, and antimicrobial peptides. It is irreplaceable for newborns. But does bovine colostrum have documented effects in healthy adults beyond infancy? This article analyzes the composition of colostrum, discusses clinical studies (including Davison et al. 2010 for athletes and gut data), explains the mechanisms of action of lactoferrin and IgG, and provides practical dosing guidelines.

KEY INFORMATION
• Bovine colostrum (BC) from the first 0–2 hours after birth contains 100–200 mg/ml of IgG, 1–10 mg/ml of lactoferrin, IGF-1, TGF-β, epidermal growth factors, and antimicrobial peptides.
• Davison et al. (BJSM, 2010, RCT, n=35): 20 g/day for 5 weeks – improvement in athletic performance and an increase in lean body mass of +1.5 kg vs placebo.
• Best indications: athletes (endurance, exercise-induced immunosuppression), leaky gut, recurrent GI infections.
• Dosage: 1–3 g/day (gut), 10–20 g/day (sport), on an empty stomach or 30 minutes before a meal.
• Contraindications: allergy to cow's milk proteins, lactose intolerance, vegans.

What does colostrum contain – composition and why it is unique

Bovine colostrum from the first hours after birth is the biologically richest form of bovine colostrum. Key active ingredients: immunoglobulins IgG (the largest fraction – 80–90% of immunoglobulins; IgG1 and IgG2 neutralize pathogens in the intestinal lumen and may act as "passive immunization" against rotaviruses, E. coli, H. pylori); lactoferrin (iron-binding glycoprotein – 1–10 mg/ml in colostrum vs 0.1–0.3 mg/ml in mature milk; antibacterial, antiviral, immunomodulatory action); growth factors: IGF-1 (Insulin-like Growth Factor 1) – stimulates the proliferation of muscle and intestinal epithelial cells; TGF-β (Transforming Growth Factor beta) – regulates the immune response and tissue repair; EGF (Epidermal Growth Factor) – regeneration of intestinal epithelium; cytokines and antimicrobial peptides: defensins, cathelicidins, lysozyme, lactoperoxidase; proline-rich peptides (PRP) – colostrum polypeptides with immunomodulatory action; lactose, fats, and proteins (casein, β-lactoglobulin, α-lactalbumin) – carrier matrix for active ingredients.

An important issue: the concentration of active ingredients drops dramatically with each hour after birth. Colostrum from the first 0–2 hours has 10–100× higher IgG concentration than milk from days 3–4. High-quality colostrum supplements should be obtained within the first 6 hours and standardized for IgG content (minimum 25–30% IgG in dry matter). Many cheap products on the market are "24-hour colostrum" or even "transition milk" – without IgG standardization. Check the composition and certifications.

Clinical studies in adults – what really works

Davison et al. (British Journal of Sports Medicine, 2010, RCT, n=35 cyclists, double-blind): 20 g/day of colostrum for 5 weeks (preparatory period) vs placebo (20 g whey); results: improvement in time-trial (40 km TT time) in the colostrum group; increase in lean body mass (+1.5 kg vs +0.4 kg placebo, p=0.04); trend towards higher IGF-1; no significant differences in VO2max. Interpretation: the effect is modest but statistically significant and reproducible. Likely mechanism: IGF-1 from colostrum stimulates muscle protein synthesis and recovery after training.

Crooks et al. (Nutrition, 2006, RCT, n=174 rowers): colostrum 60 g/day for 5 weeks – fewer upper respiratory tract infections (URTI) during the training season; the difference is statistically significant. Context: intense training causes temporary exercise-induced immunosuppression for 3–72 hours after exercise – athletes have an increased risk of URTI. Colostrum may buffer this effect through IgA in the respiratory mucosa. Antonio et al. (2001): colostrum vs whey in exercising individuals – greater gains in strength and muscle mass with colostrum after 8 weeks. However, many studies have small samples and not always uniform methodology.

Colostrum and the gut – a leaky barrier and microbiome

The intestinal barrier can be damaged by: intense physical exertion (intestinal ischemia during exercise – redistribution of blood to muscles); NSAIDs (ibuprofen, naproxen – direct damage to the mucosa); stress and chronic inflammation; a diet low in fiber and high in processed foods. A damaged barrier (increased intestinal permeability, "leaky gut") leads to the translocation of bacterial antigens into the bloodstream, chronic inflammation, and weakened systemic immunity.

How colostrum repairs the intestinal barrier: IGF-1 and EGF stimulate the proliferation and migration of enterocytes (repair of the mucosa); TGF-β regulates the expression of tight junction proteins (occludin, claudins, ZO-1); lactoferrin reduces pathogen adhesion to the mucosa and modulates the microbiome; secretory IgA (pSIgA from colostrum) protects the mucosa. Studies: Hałasa et al. (Nutrients, 2020, RCT, n=113 athletes): colostrum 3.2 g/day for 20 weeks reduced I-FABP (intestinal fatty acid binding protein – a marker of enterocyte damage) and zonulin (a marker of intestinal permeability); Playford et al. (Gut, 2001): colostrum limited intestinal damage from indomethacin (NSAID) in an RCT model in healthy volunteers. probiotics and the gut

Our observations: Colostrum is often marketed as a "miracle remedy" for immunity for everyone, but the effects in sedentary, healthy individuals without dysbiosis and without intense exertion are minimal and poorly documented. Colostrum works best where the intestinal barrier is under pressure (sports, antibiotics, NSAIDs) or where there is documented exercise-induced immunosuppression. If you are not exercising intensely and your intestines are functioning properly, other supplements are likely to give you a better return on investment – L. rhamnosus GG costs significantly less and has a better evidence base in the general population.

Lactoferrin – a component that deserves special attention

Lactoferrin (Lf) is a glycoprotein belonging to the transferrin family – iron transport proteins. Mechanisms of action of lactoferrin: antibacterial – Lf binds Fe³⁺ ions with high affinity (Ka = 10²⁰ M⁻¹), depriving pathogens of the iron necessary for growth; direct disintegration of the bacterial membrane by N-terminal lactoferricin; antiviral – direct binding to viral envelope glycoproteins (RSV, HIV-1, rotaviruses, SARS-CoV-2 – preliminary data) and blocking adsorption to cells; immunomodulatory – activation of NK cells, maturation of DC (dendritic cells), modulation of NF-κB; anti-inflammatory – reduces IL-6, TNF-α, IL-1β in inflammatory states of the mucosa.

The concentration of lactoferrin in colostrum drops quickly – highest in the first hours (5–10 mg/ml), in mature milk barely 0.3 mg/ml. Lactoferrin supplements in isolated form (100–300 mg/day) have their own growing literature: Tanaka et al. (Journal of Infectious Diseases, 2012): bLf (600 mg/day) reduced cold episodes by 65% in Japanese office workers; Wakabayashi et al. (2014): bLf improved the microbiome status in healthy adults; oncology studies: bLf shows anticancer activity in in vitro models – too early for clinical conclusions. Colostrum is a natural source of lactoferrin, but its content in products is variable – isolated bLf may be a more precise option when targeting the effects of lactoferrin.

Colostrum and gastrointestinal infections – does it work?

Gastrointestinal infections are the second indication, after respiratory infections, for which colostrum has interesting clinical data. IgG from bovine colostrum acts as "passive antibodies" – neutralizing pathogens directly in the intestinal lumen (they do not enter the bloodstream in adults, as the epithelium of the adult intestine does not have FcRn receptors for IgG like the epithelium of a newborn). Pathogens against which bovine colostrum IgG shows neutralizing activity: rotaviruses (the main cause of infant diarrhea – IgG from bovine colostrum cross-reacts with human rotaviruses); ETEC (enterotoxigenic Escherichia coli) – "traveler's diarrhea"; Helicobacter pylori (cross-reactivity of IgG); Cryptosporidium parvum – in immunosuppressed patients.

Clinical studies on GI infections: Sarker et al. (Journal of Pediatric Gastroenterology, 1998): bovine colostrum concentrate vs standard ORS (oral rehydration solution) in Bangladeshi children with ETEC – similar efficacy, but colostrum shortened the duration of diarrhea; Mitra et al. (Acta Paediatrica, 1995): colostrum immunoglobulins reduced the duration of rotavirus diarrhea by about 1.5 days; Rump et al. (Clin. Investigator, 1992): with Cryptosporidium in AIDS – colostrum (10 g IgG/day) reduced diarrhea in AIDS patients. Important note: most of these studies involved special hyperimmunized preparations (cows were deliberately vaccinated against specific pathogens, resulting in higher IgG titers against those pathogens). Standard bovine colostrum from the supplement market may have lower activity against specific pathogens than hyperimmunized products used in clinical studies.

How to dose colostrum – protocols according to goals

Protocol for gut health (leaky barrier, antibiotic therapy, NSAIDs): 1–3 g/day of colostrum powder (about ½ teaspoon); on an empty stomach or 30 minutes before breakfast – for maximum contact with the intestinal epithelium; for a course: 8–12 weeks; combine with probiotics LGG (synergism: LGG colonizes and modulates the microbiota, colostrum repairs the mucosa). Protocol for athletes (exercise-induced immunosuppression, recovery): 10–20 g/day of colostrum powder; in the morning on an empty stomach + optionally after training; for a course: 4–8 weeks during the season of intensive training; combine with protein (a protein-colostrum shake is fine – IgG and lactoferrin are quite stable in the acidic environment of the stomach). Protocol for recurrent GI infections: 20–40 g/day (doses from studies on rotaviruses and E. coli); short-term (2–4 weeks) during active traveler's diarrhea or rotavirus diarrhea.

How to choose colostrum on the market: the first rule – IgG standardization (minimum 25–30% IgG). Products without declared IgG content are of questionable value. Collection time: "0–2 hours" or "6-hour colostrum" is the gold standard; "24-hour colostrum" is significantly weaker; BSE-free certification (free from prion diseases of cattle) – essential for safety; powder form allows for easier dose control than capsules at higher therapeutic doses. immune supplements for children

Colostrum vs other gut supplements – when to choose what

In the supplement market, colostrum competes with several other approaches to gut health support. How does it compare to the competition? Colostrum vs probiotics: probiotics (LGG, L. reuteri, B. lactis Bb12) have a significantly better clinical evidence base in the general population, are cheaper, and more accessible. Colostrum is complementary to probiotics, not competitive – it repairs the mucosa (colostrum), modulates the microbiota (probiotics). The colostrum + LGG stack makes sense in cases of gut damage after antibiotics or intense training. Colostrum vs L-glutamine: L-glutamine is a nutritional amino acid for enterocytes – cheap, well-known gut support; colostrum acts in multiple ways (IgG, growth factors, lactoferrin). Glutamine is cheaper and better studied for gut mucosa in critical conditions (surgery, burns). Colostrum vs IgG (bovine serum/SBI): Serum Bovine Immunoglobulin (SBI, e.g., Enteragam) – a specialized IgG preparation from bovine serum with a very high IgG concentration (about 50% IgG dry matter); clinical data on IBS and IBD are promising. SBI is "protein-free colostrum" – better tolerated in lactose intolerance. It rarely enters the supplement market.

Final recommendation: bovine colostrum is a niche supplement with solid, albeit limited-scale, evidence. Its niche is athletes with exercise-induced immunosuppression and individuals with documented gut dysbiosis or barrier damage after NSAIDs/antibiotics. It is not a "supplement for everyone" – for overall gut health, probiotics and prebiotics have a better cost-to-effect ratio. If you are an athlete training intensely 3–5 days a week, colostrum 10–20 g/day for one training season is a well-justified investment.

Contraindications and safety issues

Cow's milk protein allergy (CMPA): colostrum contains the same allergens as milk – casein, α-lactalbumin, β-lactoglobulin. Individuals with IgE-dependent allergy or milk protein intolerance cannot use colostrum. Lactose intolerance: colostrum contains lactose (about 3–7%); individuals with intolerance may experience bloating and diarrhea at higher doses – lactose-free powder or freeze-dried preparations are an alternative. BSE (bovine spongiform encephalopathy): due to the risk of BSE prions, colostrum should come only from herds in BSE-free countries or certified. The European Union has strict regulations regarding BSE, making European colostrum relatively safe. Growth hormones and antibiotics: colostrum from conventional farming may contain trace amounts of growth hormones or antibiotics; choose products with "hormone-free" and "antibiotic-free" certifications. Pregnancy and breastfeeding: insufficient safety data – caution is advised, consult a doctor. Vegans and vegetarians: colostrum is an animal product obtained directly from the animal – it is not accepted in a vegan diet.

Frequently Asked Questions

Below are answers to the most common questions about bovine colostrum and its supplementation in adults.

What is colostrum and where does it come from?

Bovine colostrum is the first secretion of the mammary glands of cows, obtained within 0–6 hours after calving. It contains a concentrate of IgG (100–200 mg/ml), lactoferrin, IGF-1, TGF-β, and antimicrobial peptides. Standardized supplements contain ≥25% IgG and require a BSE-free certificate.

What are the proven effects of colostrum in adults?

The strongest evidence concerns: athletes (improved performance and lean mass, reduced URTI during intense training – Davison 2010, Crooks 2006) and protection of the gut barrier during exercise, NSAIDs, and antibiotics (Hałasa 2020, Playford 2001). In sedentary, healthy adults without dysbiosis, the effects are less well documented.

How to dose colostrum?

Gut: 1–3 g/day on an empty stomach, for a course of 8–12 weeks. Sport: 10–20 g/day during the training season, for a course of 4–8 weeks. GI infections: 20–40 g/day short-term. Always choose standardized products with ≥25% IgG, obtained within 6 hours after calving, with a BSE-free certificate.

Is colostrum safe?

Safe for healthy adults without milk allergies. Contraindications: CMPA allergy (casein, milk proteins), lactose intolerance (severe), products without a BSE-free certificate. Caution: pregnancy, breastfeeding, autoimmune conditions. Not for vegans.

What is lactoferrin in colostrum?

Lactoferrin is an iron-binding glycoprotein with a wide range of actions: antibacterial (deprives pathogens of iron), antiviral (blocks virus adsorption to cells), immunomodulatory, and anti-inflammatory. Concentration 5–10 mg/ml in colostrum vs 0.1–0.3 mg/ml in mature milk. Tanaka et al. (2012) showed a 65% reduction in colds with isolated bLf 600 mg/day.

Does colostrum help with leaky gut?

Yes – studies by Hałasa et al. (Nutrients, 2020) and Playford et al. (2001) confirm the reduction of intestinal permeability markers (zonulin, I-FABP) by colostrum in cases of gut barrier damage due to exercise or NSAIDs. Mechanism: IGF-1, EGF, and TGF-β stimulate enterocyte proliferation and tight junction protein expression.

This article is for informational and educational purposes and does not replace consultation with a doctor. If you are pregnant, breastfeeding, taking medications, or have chronic conditions, consult the use of supplements or herbs with a specialist.

Author: Michał Waluk · Published: 2026-05-04 · Updated: 2026-05-04