Key takeaways
- Milk allergy: cell-based milk contains the same casein and whey proteins as cow's milk. Treat it exactly like dairy.
- Lactose intolerance: mammary cells make lactose naturally, so whole-milk replicas are expected to contain it.
- Lactose-free versions are possible, using the same enzyme treatment as today's lactose-free milk.
- Precision-fermented 'animal-free' dairy usually has no lactose but still contains milk proteins.
People avoid dairy for two very different medical reasons, and cell-based milk affects each one differently. Here’s what to expect.
This article is general information, not medical advice. If you have a diagnosed allergy or digestive condition, talk to your doctor or an allergist before trying any new dairy product.
Milk allergy vs. lactose intolerance
They’re often confused, but they’re not the same thing.
- A milk allergy is an immune reaction to milk proteins, mainly casein and whey. Reactions can range from hives and stomach upset to life-threatening anaphylaxis. It’s one of the most common food allergies in young children.
- Lactose intolerance is a digestive issue. It occurs when the body produces too little lactase, the enzyme that breaks down milk sugar. It causes bloating, gas and discomfort, but it isn’t dangerous. It’s extremely common: a large 2017 meta-analysis estimated that about two-thirds of the world’s adults have reduced ability to digest lactose.
Milk allergy: assume it’s not safe
The whole point of cell-based milk is to produce the same proteins cows do. Brown Foods, for example, says its UnReal Milk contains the full set of major dairy proteins: alpha-S1, alpha-S2, beta and kappa casein, along with alpha-lactalbumin and beta-lactoglobulin. Those are exactly the proteins that trigger milk allergies.
If you’re allergic to cow’s milk, you should expect to be allergic to cell-based cow’s milk. No company has claimed otherwise, and products will almost certainly carry a milk allergen warning.
The same is true for precision-fermented “animal-free” dairy. Even though no cow is involved, the whey protein is molecularly identical to cow’s whey, and those products are labeled as containing milk allergens.
Lactose intolerance: probably contains lactose
Lactose isn’t made by the cow’s digestive system or added from its diet. It’s made right inside the mammary cells, by an enzyme complex called lactose synthase. That means a bioreactor full of mammary cells will naturally produce it too.
So a cell-based product designed as a whole-milk replica will most likely contain lactose, similar to regular milk.
But lactose-free versions are easy
Today’s lactose-free milk is regular milk with the enzyme lactase added, which splits lactose into simpler sugars before you drink it. There’s no technical reason the same process couldn’t be applied to cell-based milk, though no company has announced a lactose-free product yet.
Quick comparison
| Product | Milk proteins (allergy risk) | Lactose |
|---|---|---|
| Cow’s milk | Yes | Yes |
| Lactose-free cow’s milk | Yes | No (broken down) |
| Cell-based milk (whole-milk replica) | Yes | Expected |
| Precision-fermented “animal-free” dairy | Yes | Usually no |
| Plant milks (oat, almond, soy) | No* | No |
*Plant milks avoid milk proteins but may contain other allergens such as soy or tree nuts.
What about A2 milk?
Some people who feel unwell after milk do better with A2 milk, which contains only the A2 form of beta-casein. Because cell-based milk comes from a cell line, its beta-casein type depends on the genetics of the original cow. A producer could, in principle, start from an A2 cow’s cells. No company has announced an A2 cell-based product yet.
The bottom line
Cell-based milk is real dairy at the molecular level. If dairy is a problem for you because of allergy, it won’t solve that. If the problem is lactose, look for lactose-free versions once products launch, just as you would in the dairy aisle today.
For more on nutrition, see how cell-based milk tastes and how nutritious it is.
Sources
- Storhaug CL, Fosse SK, Fadnes LT, Country, regional, and global estimates for lactose malabsorption in adults: a systematic review and meta-analysis, Lancet Gastroenterology & Hepatology, 2017
- Brown Foods, “The World’s First Lab-Made Whole Cow Milk is Here”, February 25, 2025
- Good Food Institute, Fermentation: An introduction
