A friend recently told me they were taking colostrum as a daily supplement. I’d heard of colostrum in the normal biological sense — the “first milk” that mammals produce for newborns — but I had never come across it as an adult therapeutic.

My initial reaction to it was that when you hear the word colostrum you immediately think of immunity, newborns, and the “first fuel” that gets a developing immune system off the ground. That basic association is powerful. It makes a certain intuitive sense that if colostrum jump-starts immunity in infants, maybe taking it later in life could offer the same kind of boost.

The question is whether that logic holds up once you actually look at the research, or whether it simply sounds good enough to sell.

There are a handful of manufacturers promoting bovine colostrum as an immune booster, gut-healing agent, or even an anticancer natural therapy. Some of them cite research studies. I looked them up, here’s what I found.

What the strongest studies actually show

1. Gastrointestinal benefits: some signal, but mixed.

A 2024 systematic review of 22 clinical trials (1,427 participants) found that bovine colostrum modestly improved certain GI symptoms — mainly reducing diarrhea frequency and improving stool consistency — but results were inconsistent and highly dependent on the formulation and delivery method.

Source: https://systematicreviewsjournal.biomedcentral.com/articles/10.1186/s13643-024-02489-1

2. Cellular and molecular anticancer activity: promising, but only in labs.

A 2022 review reported that compounds in colostrum, especially lactoferrin and certain peptides, can inhibit proliferation of cancer cell lines and modulate pathways involved in tumor growth in vitro and in animals — not in humans.

Source: https://www.mdpi.com/1420-3049/27/24/8641

3. Broad immune effects: plausible but unproven in humans.

A 2020 review in Frontiers in Pharmacology concluded that colostrum contains immunoglobulins, growth factors, and antimicrobial peptides that could influence immune responses, but emphasized the absence of strong human clinical data.

Source: https://www.frontiersin.org/articles/10.3389/fphar.2020.01100/full

An interesting graphic from the cited study illustrates the authors’ proposed mechanisms of action for bovine colostrum. These ideas reflect the authors’ theory, not established science. The image is included only to provide context for what is being claimed.

What the evidence does not show

• There are no strong clinical trials showing colostrum prevents cancer, treats cancer, or improves survival.
• There is no confirmed mechanism showing that orally consumed colostrum survives digestion in meaningful amounts.
• There is no standardized dosing across commercial products, which vary widely in bioactive content.

Does colostrum make theoretical sense?

Maybe — but only in a narrow way.

Colostrum plays an essential role in early life. It delivers immunoglobulins, growth factors, and antimicrobial compounds to help newborns develop a functioning immune system. It is one of nature’s most elegant biological solutions.

But evolution also tells us something important:

Humans stop receiving colostrum after a very short window because the immune system quickly takes over for itself.

If colostrum were meant to be a lifelong input, mammals would consume it throughout life. They don’t.

This doesn’t mean colostrum can’t help certain people in specific ways — especially in contexts of gut damage, infection, or immune stress. But it does mean we should be cautious about claims that it can “boost immunity” or act as an anticancer therapy without clear human evidence.

Bottom line

Colostrum is interesting. There is early evidence of GI benefit, plausible immune effects, and promising laboratory data. But human studies are limited, inconsistent, and nowhere near strong enough to justify the more enthusiastic claims.

If you’re curious or considering it, go in with realistic expectations:

Colostrum may help with gut integrity, but it is not a proven cancer treatment or broad immune therapy.

The science simply isn’t there yet — and as always, we’ll keep following it as it develops.