Colostrum science · 7 min read
Colostrum IgG Percentage Explained
Immunoglobulin G is the protein most colostrum research is built around, and its percentage is the only figure that lets you compare two powders directly. Most premium brands do not print it.
In short
- IgG percentage tells you what share of the powder is immunoglobulin G, the most studied bioactive in colostrum.
- Rough industry bands: 5–10% is budget and usually diluted; 15–20% is mainstream premium; 25–40% is standardised and concentrated.
- A high IgG percentage is not automatically better — it often means the powder has been fractionated or standardised.
- Several of the most expensive brands, including ARMRA and Anovité, publish no IgG figure at all.
- When there is no percentage, fall back on collection window, sourcing detail and a current certificate of analysis.
What IgG percentage actually measures
Immunoglobulin G is an antibody. In colostrum it is the dominant immunoglobulin and the one most of the published research uses as its marker. When a label says "40% IgG", it means that by weight, 40% of the powder is immunoglobulin G.
That makes it the single most comparable number in the category. Two powders with stated IgG percentages can be compared on cost per gram of IgG. Two powders without them cannot be compared on anything except marketing.
The bands, and what they signal
Working figures used across the industry break down roughly like this.
5–10% IgG. Budget territory. Powders in this band are frequently blended with skim milk powder, which dilutes everything else in the tub along with the IgG.
15–20% IgG. Mainstream premium, and the band most clinical work sits in. If a brand publishes a figure here with real sourcing detail behind it, that is a reasonable place to be.
25–40% IgG. Standardised and concentrated. Brands including WonderCow state 40%. Reaching this band almost always means the powder has been processed to get there.
Why higher is not automatically better
This is the part the category gets wrong. A 40% IgG powder is not four times better than a 10% one, and it may not be better at all.
Colostrum contains hundreds of constituents besides IgG: lactoferrin, proline-rich polypeptides, growth factors, oligosaccharides, fatty acids. When a manufacturer standardises to a high IgG figure, that concentration usually comes from removing other components. You have optimised for the one number the label prints, which is not the same thing as optimising for the product.
Whole-colostrum brands such as Anovité make the opposite bet: keep everything, publish no headline number. Both positions are defensible. What is not defensible is a brand that neither publishes a number nor explains why.
What to do when there is no IgG figure
Several of the most expensive colostrum products on the market publish nothing. ARMRA does not state an IgG volume per serving. Sovereign Laboratories does not put one on the label. Anovité does not standardise to one.
When the number is missing, work down this list instead.
1. Collection window. Does the brand state the hours after calving in which it collects? A stated window is a checkable commitment.
2. First milking. Is it first-milking only, or blended across milkings?
3. Processing. Low-temperature drying preserves more than high-heat processing. Has fat or casein been removed?
4. Certificate of analysis. Ask for the current batch COA. Ask which lab ran it. A brand that names its lab is in a different category from one that says "third-party tested" and stops there.
5. Ingredient list length. If the tub contains sugar, flavouring or bulking agents, potency questions are academic — you are buying a drink mix.
The practical version
If you want the cheapest verified immunoglobulins, buy a brand that publishes a standardised IgG percentage and compare on cost per gram of IgG.
If you want the whole food and are prepared to judge on provenance instead of a single marker, buy on collection window and certificate of analysis.
What you should not do is pay premium prices to a brand that gives you neither.
Frequently asked questions
What is a good IgG percentage for colostrum?
For a standardised powder, 15–20% IgG is mainstream premium and is the band most clinical research sits in. Figures of 25–40% indicate a concentrated or standardised product. Below 10% usually indicates dilution with skim milk powder.
Is 40% IgG colostrum better than 20%?
Not necessarily. A higher IgG percentage is usually achieved by removing other components of colostrum. You get more of one measured protein and less of everything else. Which is better depends on whether you are buying colostrum for IgG specifically or for the whole profile.
Why do premium colostrum brands not publish IgG?
Two different reasons. Whole-colostrum brands such as Anovité do not standardise to a fixed marker, so there is no single figure to print. Other brands simply choose not to disclose it, which is a marketing decision rather than a technical constraint.
What is the IgG content of Anovite Colostrum6?
Anovité does not publish a standardised IgG percentage for Colostrum6. The product is sold as whole, unfractionated colostrum rather than standardised to a fixed marker. If a published IgG figure is essential to your decision, choose a brand that states one.
Does a higher IgG percentage mean a smaller dose works?
In principle yes, if IgG is the only thing you care about. In practice, most positive clinical results in colostrum research come from total daily colostrum doses substantially larger than a typical supplement serving, regardless of concentration.
What else should be on a good colostrum label?
Collection window, first-milking status, country and herd standard, processing temperature, whether fat and casein remain, and a reference to third-party testing with a named lab.
Should I ask for a certificate of analysis?
Yes. A current batch certificate of analysis is the single most useful document a supplement buyer can request, and any brand charging premium prices should be able to supply one without friction.