Does pasteurization remove lactoferrin from milk?

Mostly, yes. How much it removes depends on how hot the milk got, and that is the part worth knowing. One word on the carton covers a range of heat wide enough to move the answer from "most of it survives" to "none of it does".

Milk is the main food source of lactoferrin, and the protein only does anything while it holds its folded shape. Heat unfolds it. So the question is never whether milk was heated. It is how hot, for how long, and whether the label lets you find out.

What "pasteurized" is allowed to mean

Federal regulation does not define pasteurization as one temperature. It lists five, each with its own holding time, and a product heated by any of them may be labeled pasteurized.

The regulation adds 5 °F to the first two rows for anything 10% fat or more, or with sweeteners added, which is why cream runs hotter than milk. It also allows any other combination shown to kill microbes equally well.

Top row to bottom row is a 67 °F spread, and a carton reading simply "pasteurized" sits somewhere on it without telling you where. That is the real shape of this question, and it is why a single answer about lactoferrin and pasteurized milk cannot be right for every carton.

Where lactoferrin falls on that scale

One row of that table is the one most milk actually goes through. The FDA names 161 °F for 15 seconds as the combination "most commonly utilized by the dairy industry", and calls it high-temperature-short-time, or flash pasteurization. If you are holding a refrigerated carton, this is the likely history of what is inside it.

That row is also the only one with a close match in the measurement record. A 2026 study in Foods ran one farm's raw milk through seven heat treatments and measured what was left of each protein by ELISA. Its gentlest heated step was 75 °C for 15 seconds, three degrees above the legal row, and about 65% of the lactoferrin came through it. At 85 °C the figure fell to 13%. At 95 °C the assay found none. The full ladder, with the other milk proteins alongside it for contrast, sits on the page about foods high in lactoferrin.

So an ordinary flash-pasteurized carton has probably kept a majority of its lactoferrin, since it was heated slightly less hard than the step that retained 65%.

Here is where the record runs out, and the gap is worth stating plainly. Every heated step in that study was held for 15 seconds or more. The regulation's three hottest rows are held for one second, a twentieth of a second and a hundredth of a second, and nobody has measured lactoferrin after those. Temperature and time trade against each other, so you cannot read 191 °F for 1 second off a 15-second curve. Milk processed that way may keep more lactoferrin than the bare temperature suggests, or less. No study on this site's reading list answers it.

Ultra-pasteurized is the word that changes the answer

"Ultra-pasteurized" is a separate legal term with its own definition, and it is the distinction that does the work here. It means the product was heated to at least 280 °F (138 °C) for at least two seconds, which buys it a long refrigerated shelf life. A carton carrying that word is making a claim with a temperature behind it.

Compare that with the study's UHT arm: 135 °C for 5 seconds, after which lactoferrin was undetectable. The legal ultra-pasteurized minimum is three degrees hotter than that. The hold is shorter, so the two are not identical, but 138 °C sits far above 95 °C, where 15 seconds already left nothing measurable.

Treat a carton marked ultra-pasteurized as a carton with no meaningful lactoferrin in it. The same goes for the shelf-stable boxes that need no refrigeration until opened. This is the most useful line on the label for anyone asking about lactoferrin, and it sits right next to the word most shoppers stop reading at.

Is raw milk the answer, then?

No. Raw milk does hold more lactoferrin than any heated milk, and that is the one place where the raw-milk argument has real evidence under it. It is still a bad trade.

The FDA counts at least 133 raw-milk-linked outbreaks in the US between 1987 and September 2010. Set against that, nobody has run a trial giving people raw milk to find out whether the lactoferrin in it does anything at all, so the gain is unmeasured while the risk is counted. The fuller version of this argument, including why the FDA can say pasteurization costs milk nothing nutritionally while this page says it costs most of the lactoferrin, is worked through on the foods page.

What to read on the carton

Four things, in order.

1. Look for the word "ultra-pasteurized". If it is there, assume the lactoferrin is gone.
2. Check whether the carton is shelf-stable. Boxes stored unrefrigerated are heated past the point where any survives.
3. If it says only "pasteurized" and lives in the chiller, it was most likely flash-pasteurized, and a majority of the lactoferrin probably survived.
4. Accept that the label stops there. No carton states its temperature, and none states a lactoferrin content.

That last line is the limit of what shopping can do. If a known daily amount is what you are after, milk cannot give you one, and the trials behind how much lactoferrin per day all used purified protein at a measured dose instead. A lactoferrin supplement is what that job needs, which is a point about dose and not a claim that the dose works.