Colostrum IgG vs Lactoferrin: Which Immune Compound Actually Matters More?
If you're shopping for a colostrum supplement, you've probably seen brands touting both IgG and lactoferrin like they're equally important. But here's the thing: they're not the same, they don't do the same job, and one of them deserves a lot more of your attention. Let's cut through the noise and talk about what actually matters when you're choosing a colostrum product.
The Plain Answer First: IgG Is the MVP
IgG (immunoglobulin G) is the primary immune antibody in colostrum — think of it as the trained security team that recognizes threats and neutralizes them. It's the most abundant antibody in your bloodstream and in colostrum, and it does the heavy lifting when it comes to immune support.
Lactoferrin is a different animal entirely. It's an iron-binding protein that does have immune properties, but it plays a supporting role. Both are good to have, but if you had to pick one, IgG is where the action happens. Research suggests IgG is responsible for much of colostrum's well-known benefits for immune function and gut health.
The catch? Most colostrum brands don't actually tell you how much bioactive IgG they contain — and there's a reason for that.
Why IgG Transparency Matters More Than You Think
Here's where it gets interesting. Some brands use harsh processing methods — high heat, aggressive extraction — that damage IgG proteins. The protein count looks fine on paper, but the IgG molecules are broken down and no longer functional. It's like having a security team on the payroll that's asleep on the job.
When labs test colostrum, they measure total protein content. But without turbidity-corrected testing (a method that accounts for damaged proteins), you can't tell if that IgG is actually bioactive or just broken fragments. Some brands report inflated IgG numbers because they're measuring damaged protein alongside the real deal. A lower, accurately tested number beats a higher inflated one every single time.
This is why knowing the source, processing method, and testing standards matters more than the marketing headline. Lactoferrin is great, but if your IgG is damaged before it enters your system, you're missing the primary benefit of taking colostrum at all.
Why New Zealand Colostrum Changes the Game
At kāre, we measure what actually counts: bioactive IgG. Our colostrum comes from grass-fed, pasture-raised cows on New Zealand's South Island that roam freely 365 days a year. That clean source matters. But here's what really sets us apart: we process fresh (never frozen) within 48 hours of collection using gentle, low-temperature spray-drying between 37–60°C. That's cool enough to preserve the IgG proteins so they arrive in your system ready to work.
We use turbidity-corrected testing, so when we report IgG levels, we're telling you about bioactive protein, not theoretical numbers. Our cows are never routinely vaccinated or artificially stressed — they're just cows being cows on clean pasture. And yes, the calves get their first 4 litres before we collect anything. Ethics and quality aren't separate from performance; they're the same thing.
Lactoferrin is present in our colostrum too, but we don't inflate its importance to distract from what actually matters. We focus on what the research shows: IgG is the bioactive compound that supports immune function, and gut health improvements typically track with IgG quality.
The Bottom Line
Both IgG and lactoferrin belong in colostrum, but they're not interchangeable. IgG is the primary player, and its bioactivity depends entirely on how the colostrum was sourced and processed. When you're choosing a supplement, skip the brands that hide behind vague "immune support" claims and look for ones that test and report bioactive IgG specifically. That's the difference between a product that works and one that just sounds good on the label.
Ready to experience the difference that transparent, ethically sourced, properly processed colostrum makes? Try kāre and feel the real thing.
