Colostrum: what it is, how it is made and what the research says
26 October, 2026Short answer: Colostrum is the first milk a cow produces after calving. It is rich in proteins called immunoglobulins. Our Colostrum 100% is a powder from pasture raised New Zealand dairy cows, standardised to a minimum of 20% IgG. Some small trials in people who exercise regularly suggest colostrum may reduce days with upper respiratory symptoms, but the evidence is limited and needs larger trials.
What colostrum is
Colostrum is the nutrient rich first milk produced by cows after calving. It naturally contains proteins, immunoglobulins, vitamins and minerals. Immunoglobulins, often shortened to IgG, are a group of antibody proteins.
What is in a capsule
Each NZ Pure Health Colostrum 100% capsule holds 500mg of bovine colostrum powder with a minimum of 20% IgG, plus the capsule materials. We source premium New Zealand colostrum, and the powder is spray dried in traceable batches. It has no artificial flavours, colours or preservatives. The product contains milk.
What the research says
In 2016, a systematic review pooled five randomised trials of bovine colostrum in 152 adults who exercise regularly (Jones and colleagues, BMC Sports Science, Medicine and Rehabilitation). Compared with placebo, colostrum was linked to fewer days with upper respiratory symptoms (a 44% lower rate) and fewer episodes (a 38% lower rate). Trials used between 10g and 20g of colostrum a day over 8 to 12 weeks.
The authors were careful about what this shows. Four of the five trials had a moderate or high risk of bias, the numbers were small, and they called for a larger trial to confirm the result. One author's research had partly been supported by a colostrum supplier.
A second area of research is gut permeability in athletes. A 2022 systematic review of nine studies (Dziewiecka and colleagues, Nutrients) found the results mixed. Some studies found colostrum reduced signs of increased gut permeability after hard exercise, others found no change. The authors said better designed trials are needed to confirm effects, long term safety and the right dose.
Three limits apply to all of this. Most participants were men who exercise regularly, so the results may not apply to everyone. The doses in trials were often higher than the amount in a capsule. And the research is on colostrum generally, not on our product specifically.
Who should talk to a healthcare professional first
- Anyone with a milk allergy should not take colostrum.
- Anyone who is pregnant or breastfeeding.
- Anyone taking prescription medicines or managing a health condition.
Colostrum is not a balanced diet and should not replace food. Some people with dairy sensitivity report digestive side effects such as wind or nausea.
How to take it
Follow the directions on the label, or as professionally advised. For adults the label suggests taking it on an empty stomach with a glass of water, then avoiding food or other supplements for 20 minutes afterwards.
Common questions
What does IgG mean?
IgG stands for immunoglobulin G, a type of antibody protein. Our colostrum is standardised to a minimum of 20% IgG.
Is colostrum the same as milk?
No. It is the first milk after calving and is higher in proteins such as immunoglobulins. It still comes from cows, so people with milk allergy should avoid it.
Can children take it?
The label gives a dose for children aged 3 to 12. Check with your doctor or pharmacist first.
How long until I notice anything?
The trials ran for 8 to 12 weeks. Individual results vary, and some people notice nothing.
Sources
- Jones AW, March DS, Curtis F, Bridle C. Bovine colostrum supplementation and upper respiratory symptoms during exercise training: a systematic review and meta-analysis of randomised controlled trials. BMC Sports Science, Medicine and Rehabilitation, 2016;8:21. pmc.ncbi.nlm.nih.gov/articles/PMC4960812
- Dziewiecka H, Buttar HS, Kasperska A, Ostapiuk-Karolczuk J, Domagalska M, Cichon J, Skarpanska-Stejnborn A. A systematic review of the influence of bovine colostrum supplementation on leaky gut syndrome in athletes: diagnostic biomarkers and future directions. Nutrients, 2022;14(12):2512. pmc.ncbi.nlm.nih.gov/articles/PMC9227274
Written by Liz Lawton. Last updated 26 October 2026. This article is general information and is not medical advice.
