Bovine colostrum is a nutrient-rich substance naturally produced by cows shortly after giving birth. While its primary purpose is to provide nutrition to newborn calves, bovine colostrum can also be processed into supplements for human consumption. So, what makes it different from regular milk, and why do people take it?

What is bovine colostrum?

Bovine colostrum is the first milk produced by cows shortly after giving birth. Its natural purpose is to provide newborn calves with concentrated nutrition and important bioactive compounds during their first stages of life.

Colostrum is different from the regular cow's milk produced later in lactation. It generally contains higher concentrations of protein and certain bioactive components, including immunoglobulins, lactoferrin and growth factors. These components help explain why bovine colostrum has attracted interest beyond its natural role in supporting newborn calves.

For use as a dietary supplement, bovine colostrum can be collected and processed into a powder, making it easy to mix with water, smoothies, yoghurt or other foods. The exact nutritional and bioactive composition can vary depending on factors such as when the colostrum is collected, the health and diet of the cows, and how it is processed.

Importantly, responsible sourcing should prioritise the needs of the calf first. Colostrum is essential for newborn calves, so reputable producers may collect surplus colostrum only after calves have received the amount they require.

So, what makes bovine colostrum different from an ordinary dairy supplement? Much of the answer comes down to the unique combination of naturally occurring compounds it contains — which we'll look at next.

What's actually in bovine colostrum?

What makes bovine colostrum different from regular cow's milk is its concentrated mix of nutrients and naturally occurring bioactive compounds. Its composition is designed to meet the needs of a newborn calf, but many of these same components are also what have made bovine colostrum interesting to researchers and supplement manufacturers.

Here are some of the key components you may see mentioned on bovine colostrum supplements.

Immunoglobulins

Bovine colostrum is naturally rich in immunoglobulins, also known as antibodies. These are proteins involved in the immune system's ability to recognise and respond to potentially harmful microorganisms.

The main immunoglobulins found in bovine colostrum include IgG, IgA and IgM, with IgG generally being the most abundant. This is why you'll often see the IgG concentration or percentage displayed on colostrum supplements — it can be used as one indicator when assessing the composition and quality of a product.

Lactoferrin

Lactoferrin is an iron-binding protein naturally found in colostrum and other bodily fluids. It has attracted considerable research interest because of its involvement in a range of biological processes, including immune function and the body's interactions with microorganisms.

Lactoferrin is one of several components researchers are investigating when looking at the potential applications of bovine colostrum for gut and digestive health.

Growth factors

Colostrum also naturally contains various growth factors. These are signalling proteins involved in processes such as cell growth, development and tissue maintenance.

Their presence is particularly important for newborn animals during early development. Researchers have also investigated whether some of these compounds could contribute to the potential effects of bovine colostrum on the intestinal lining and gut barrier.

Oligosaccharides

Another interesting component is oligosaccharides — complex carbohydrates naturally present in colostrum.

Some oligosaccharides can interact with microorganisms living in the digestive tract and may act as prebiotic compounds, providing a food source for certain beneficial gut bacteria. This is one reason they're of growing interest in research looking at the relationship between colostrum and the gut microbiome.

Protein and other nutrients

Bovine colostrum also provides protein, fats, carbohydrates, vitamins and minerals, although the exact amounts can vary considerably between products.

It's therefore useful to think of colostrum as more than one particular ingredient. Rather, it's the combination of immunoglobulins, lactoferrin, growth factors, oligosaccharides and other naturally occurring nutrients that gives bovine colostrum its distinctive composition.

And it's this combination that has led researchers to investigate whether bovine colostrum supplementation could have benefits beyond basic nutrition — particularly when it comes to gut and intestinal health.

Why do people take colostrum supplements?

Bovine colostrum supplements are taken for several reasons, with much of the interest centred around gut health, immune function and sports nutrition. 

Research into these potential benefits is ongoing, and the strength of the evidence varies depending on the area being studied. Here's a closer look at some of the main reasons people take bovine colostrum supplements.

Gut and intestinal health

One of the most researched potential uses of bovine colostrum is its role in supporting the gut and intestinal barrier.

The intestinal barrier is the protective lining of the digestive tract. It helps the body absorb nutrients while controlling what passes from the gut into the bloodstream. When this barrier becomes more permeable than normal, substances can pass through it more easily — a change commonly referred to as increased intestinal permeability.

Bovine colostrum contains several components that have attracted interest for their potential role in maintaining this barrier, including growth factors, lactoferrin and immunoglobulins.

A 2024 systematic review looked more broadly at whether bovine colostrum supplementation could affect symptoms associated with gastrointestinal conditions. Researchers reviewed 22 clinical trials involving 1,427 participants, including both children and adults. The studies covered a range of populations and gastrointestinal concerns, including diarrhoea, H. pylori infection and colitis, and assessed outcomes such as diarrhoea frequency and duration, stool frequency, abdominal pain and other digestive symptoms. 

The findings were mixed. Diarrhoea frequency decreased in 15 of the 20 intervention groups in which it was assessed, and all seven studies that measured stool frequency reported a reduction. However, most studies found no improvement in the duration of diarrhoea, while results for abdominal pain and several other gastrointestinal symptoms were inconsistent. The studies also varied considerably in their participants, colostrum preparations, doses and treatment periods.

The researchers therefore concluded that although bovine colostrum shows potential in some areas of gastrointestinal health, the overall clinical evidence remains limited, and more well-designed controlled trials are needed before firm conclusions can be made.

Gut microbiome

Bovine colostrum has also attracted attention in gut microbiome research.

The gut microbiome refers to the large community of microorganisms living within the digestive tract. Diet is one of many factors that can influence this community.

Colostrum naturally contains oligosaccharides, which are complex carbohydrates. Some of these compounds aren't fully digested in the upper digestive tract and can instead reach the colon, where they may act as a food source for certain gut bacteria. This is why some bovine colostrum oligosaccharides are described as having prebiotic properties.

Immune health

Another reason people take bovine colostrum is because it naturally contains several components associated with the immune system, particularly immunoglobulins such as IgG, IgA and IgM, as well as lactoferrin.

Because of this composition, researchers have investigated whether bovine colostrum supplementation may influence different measures of immune function.

Some studies involving physically active adults have reported fewer days or episodes of upper respiratory symptoms among people taking bovine colostrum. However, the number of studies has been relatively small and their quality has varied.

Exercise and recovery

Bovine colostrum has also been studied in athletes and physically active people, which is why you'll sometimes find it included within the sports nutrition category.

One area researchers are particularly interested in is what happens to the gut during prolonged or strenuous exercise. Intense exercise can temporarily place stress on the digestive system and affect intestinal permeability in some people.

Because of the research around colostrum and the intestinal barrier, studies have explored whether supplementation could help reduce exercise-related changes in gut permeability. A 2024 meta-analysis included research involving healthy athletes and found an overall reduction in certain measures of intestinal permeability following bovine colostrum supplementation.

Bovine colostrum vs human colostrum: Are they the same?

Although bovine and human colostrum serve a similar purpose, they aren't the same. Both are the first milk produced after birth and provide newborns with concentrated nutrition and bioactive compounds during an important stage of early development. However, their composition differs because each is naturally designed to meet the needs of a different species.

One of the key differences is their immunoglobulin profile. Bovine colostrum contains particularly high concentrations of IgG, which plays an important role in providing newborn calves with antibodies. Human colostrum, on the other hand, is especially rich in secretory IgA, an antibody that helps protect mucosal surfaces such as those lining the digestive and respiratory systems.

There are differences in other components too. Both contain lactoferrin, growth factors, proteins and oligosaccharides, but their concentrations and specific types can vary. Human colostrum, for example, contains a particularly diverse range of human milk oligosaccharides (HMOs), including 2′-fucosyllactose (2′-FL), lacto-N-tetraose (LNT) and several sialylated oligosaccharides. These complex carbohydrates help shape the developing infant gut environment, including by providing a food source for certain beneficial gut bacteria.

Is bovine colostrum safe for everyone?

Bovine colostrum is generally considered well tolerated by healthy adults, and studies using colostrum supplements have typically reported few serious adverse effects. 

What if you have a cow's milk allergy?

Because bovine colostrum comes from cows, it naturally contains cow's milk proteins, including casein and β-lactoglobulin. These proteins can trigger reactions in people with a cow's milk protein allergy.

For this reason, people with a diagnosed cow's milk allergy should generally avoid bovine colostrum unless advised otherwise by their healthcare professional. A milk allergy is different from lactose intolerance and can potentially cause much more serious reactions.

What about lactose intolerance?

Bovine colostrum naturally contains lactose, although generally at a lower concentration than mature cow's milk.

Someone with lactose intolerance may therefore tolerate a colostrum product differently from ordinary milk, but this will depend on the amount of lactose in the particular supplement and the person's individual tolerance. Possible symptoms can include bloating, abdominal discomfort, gas or diarrhoea.

Are there any side effects?

Where side effects have been reported, bovine colostrum supplements have generally been associated with mild and temporary digestive symptoms, such as gas, diarrhoea or abdominal discomfort.

As with any new supplement, it's a good idea to follow the recommended serving instructions rather than assuming that taking a larger amount will provide greater benefits.

Pregnancy, breastfeeding and children

There's less evidence available on routine bovine colostrum supplementation during pregnancy and breastfeeding, and research in children has produced more variable findings than research in adults. Reviews of the evidence have highlighted the need for further well-designed studies across different populations.

If you're pregnant or breastfeeding, considering colostrum for a child, have an existing medical condition or take regular medication, it's sensible to speak with a doctor or other qualified healthcare professional before adding a colostrum supplement to your routine.

Conclusion: Is bovine colostrum worth considering? 

Bovine colostrum is more than simply another source of protein. Its naturally occurring combination of immunoglobulins, lactoferrin, growth factors, oligosaccharides and other nutrients is what makes it an interesting area of nutritional research.

So far, some of the most promising research has focused on gut and intestinal health, particularly the potential effects of bovine colostrum on intestinal barrier function and permeability. There is also ongoing research into its possible roles in the gut microbiome, immune health and sports nutrition.

If you're considering a bovine colostrum supplement, it can help to look beyond the marketing claims. Consider factors such as how the colostrum is sourced and processed, its IgG concentration, independent testing, added ingredients and the transparency of the manufacturer.

Ultimately, bovine colostrum may be worth considering as part of your broader nutrition routine, particularly if you're interested in its unique nutritional profile and emerging gut-health research.

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