Is there lactose in casein?
Low — usually gentler than whey concentrate.
Casein protein (including micellar casein and caseinate) is low in lactose, because the processing that isolates the protein removes most of the milk sugar. Many lactose-sensitive people tolerate it well, but check the label.
Casein is the other major milk protein alongside whey, and it’s a popular “slow” protein powder. Here’s the reassuring bit if you’re lactose-sensitive: the filtering that isolates casein (as micellar casein or caseinate) strips out most of the milk sugar, so it’s low in lactose — typically gentler than a basic whey concentrate.
Worth ruling out: if a casein shake still bloats you despite the low lactose, it’s worth asking whether it’s the milk protein you’re reacting to rather than lactose. They’re different things — one’s a sugar, one’s a protein.
How much lactose is in casein protein?
Casein and caseinate contain roughly 0.1–1 g of lactose per 100 g — under 0.3 g in a 30 g scoop, low enough that most sensitive people tolerate it. Exact amounts vary by product grade, so the label is your best guide.
| Food | Lactose per 100 g | Per 30 g scoop |
|---|---|---|
| Casein / caseinate | 0.1–1 g | <0.3 g |
| Whey protein concentrate | 4–8 g | ~1.2–2.4 g |
| Plant protein (pea, rice) | 0 g | 0 g |
Figures from manufacturer and industry data (vary by processing grade) — see the full lactose chart & sources.
When to take a little care
Cheaper blends may mix casein with whey concentrate or added milk solids, nudging the lactose up. Look for “micellar casein,” “caseinate,” “isolate” or “lactose-free,” or compare options on our lactose content chart.
If casein isn't handy, reach for…
Common questions
Is casein protein OK for lactose intolerance?
Is casein lower in lactose than whey?
Does casein cause bloating?
Want the full picture? Grab our free Living Lactose-Free in Australia cheat sheet — it sorts 60+ foods like this one so you never have to guess at the supermarket again.