Is Greek Yogurt Lactose Free? What the Evidence Says
The verdict: Greek yogurt is low in lactose, not lactose free
Regular Greek yogurt still contains lactose, so it is not lactose free. It does have much less than milk: plain nonfat Greek yogurt has about 2.5 grams of lactose per 100 grams, roughly half the 5 grams in whole milk, according to USDA FoodData Central. Its live cultures also help break down the lactose that remains, which is why many people with lactose intolerance handle it well.
If you need zero lactose, choose one labeled lactose free. If you only need less, plain Greek yogurt is one of the gentler dairy choices.
What the research shows
How much lactose is in Greek yogurt
USDA lab data give a clear picture. Plain nonfat Greek yogurt has 2.54 grams of lactose per 100 grams (USDA, Greek yogurt, plain, nonfat), and plain low-fat Greek yogurt has 2.92 grams (USDA, Greek yogurt, plain, lowfat). Whole milk has 5.05 grams per 100 grams (USDA, whole milk). The same USDA entry for nonfat Greek yogurt lists 0.7 grams of galactose, one of the two sugars lactose splits into, a sign that the cultures had already broken some of it down.
| Food (USDA serving) | Lactose per serving | Lactose per 100 g |
|---|---|---|
| Whole milk, 1 cup (244 g) | About 12.3 g | 5.05 g |
| Nonfat milk, 1 cup (245 g) | About 12.5 g | 5.09 g |
| Plain nonfat Greek yogurt, 1 container (170 g) | About 4.3 g | 2.54 g |
| Plain low-fat Greek yogurt, 1 container (200 g) | About 5.8 g | 2.92 g |
Per-serving figures are calculated from the USDA values per 100 grams and USDA serving weights (USDA, nonfat milk). A 6-ounce cup of plain nonfat Greek yogurt carries roughly a third of the lactose in a cup of milk.
Why straining removes lactose
Greek yogurt is regular yogurt with much of its liquid whey drained away (see how Greek yogurt is made). That whey is where much of the lactose goes. A Cornell analysis of acid whey from Greek yogurt plants found lactose was its main component, at up to 3.5 percent (Menchik et al., Journal of Dairy Science, 2019).
Time matters a little too. In a lab study from the Agricultural University of Athens, whey drained 24 hours after the yogurt was made contained slightly less lactose than whey drained right after incubation, because the cultures kept fermenting it (Karastamatis et al., Foods, 2022). The difference was small.
Live cultures help digest what is left
Yogurt bacteria carry their own lactase, the enzyme that splits lactose. In a classic breath-hydrogen study of lactase-deficient adults, 18 grams of lactose eaten as yogurt produced only about a third as much hydrogen as the same lactose in milk or water, and fewer reports of diarrhea or gas (Kolars et al., New England Journal of Medicine, 1984).
A follow-up trial in nine lactase-deficient people found that pasteurizing yogurt after fermentation removed the benefit, cutting its lactase activity tenfold and its bacteria count a hundredfold (Savaiano et al., American Journal of Clinical Nutrition, 1984). A 2014 review concluded that lactose in yogurt is digested more efficiently than in other dairy foods because the bacterial lactase survives the stomach and works in the small intestine (Savaiano, American Journal of Clinical Nutrition, 2014).
How much lactose most people can handle
A systematic review of 36 randomized trials found moderate-quality evidence that most adults with lactose intolerance or malabsorption can tolerate 12 to 15 grams of lactose, about one cup of milk (Shaukat et al., Annals of Internal Medicine, 2010). The NIDDK gives a similar figure of 12 grams and suggests trying yogurt and hard cheeses, which are lower in lactose than other milk products. A cup of plain Greek yogurt sits well under that.
Caveats to keep in mind
- Low is not zero: people who react to small amounts may still notice symptoms.
- Flavored cups differ: the 2014 review found flavored yogurts showed somewhat less lactase activity than plain ones, though they were still well tolerated (Savaiano, 2014).
- Live cultures matter: yogurt heated after fermentation loses most of its lactase help, as the 1984 pasteurized-yogurt trial showed. Our guide to whether all yogurt has probiotics explains what to look for.
- Milk allergy is a different problem: lactose intolerance is a digestive issue, while a milk allergy is an immune system disorder (NIDDK). Greek yogurt, lactose free or not, still contains milk proteins and is not safe for someone with a milk allergy.
- Tolerance varies: about 36 percent of people in the United States have lactose malabsorption, but only those with symptoms are considered lactose intolerant (NIDDK).
This article is general information, not medical advice. If dairy regularly causes pain, diarrhea or other symptoms, talk with a doctor before cutting out foods on your own.
How to choose and use Greek yogurt if lactose bothers you
- Start plain and small. Try a few spoonfuls of plain Greek yogurt with a meal. NIDDK suggests having small amounts of dairy at a time, with meals, and adding more gradually to see how you feel.
- Pick yogurt with live cultures. Avoid products labeled as heat treated after culturing, since the cultures are what help digest the lactose.
- Go lactose free when you need zero. NIDDK notes that lactose-free and lactose-reduced milk products can lower the lactose in your diet and are just as healthy as regular dairy.
- Strain longer at home. If you make your own, draining more whey removes more of the lactose with it. Our guides to making Greek yogurt and using the leftover whey cover the method.
Frequently asked questions
Is Greek yogurt lactose free?
No. Plain nonfat Greek yogurt has about 2.5 grams of lactose per 100 grams, about half as much as milk (USDA).
Does Greek yogurt have less lactose than regular yogurt?
Usually yes, because straining drains off whey, and lactose is the main component of that whey. The exact amount varies by brand and how long the yogurt is strained.
Can I eat Greek yogurt if I am lactose intolerant?
Many people can, especially in small portions with meals, because most adults with lactose intolerance tolerate 12 to 15 grams of lactose (Shaukat et al., 2010). Start small and see how you feel.
Is lactose-free Greek yogurt safe for a milk allergy?
No. Removing lactose does not remove milk proteins, which are what trigger a milk allergy.
Related topics
- What Is Greek Yogurt?: how it differs from regular yogurt.
- How Is Greek Yogurt Made?: the straining step that removes whey and lactose.
- Greek Yogurt and Milk: nutrition side by side and how milk becomes Greek yogurt.
- Is Yogurt Good for Upset Stomach?: what the evidence says.
- Best Milk for Gut Health: lactose-free and other options.
Sources
- Yogurt, Greek, plain, nonfat (USDA FoodData Central)
- Yogurt, Greek, plain, lowfat (USDA FoodData Central)
- Milk, whole, 3.25% milkfat, with added vitamin D (USDA FoodData Central)
- Milk, nonfat, fluid, with added vitamin A and vitamin D (USDA FoodData Central)
- Menchik P, et al. Short communication: Composition of coproduct streams from dairy processing: Acid whey and milk permeate (Journal of Dairy Science, 2019)
- Karastamatis S, et al. Effect of Modified Manufacturing Conditions on the Composition of Greek Strained Yogurt and the Quantity and Composition of Generated Acid Whey (Foods, 2022)
- Kolars JC, et al. Yogurt: an autodigesting source of lactose (New England Journal of Medicine, 1984)
- Savaiano DA, et al. Lactose malabsorption from yogurt, pasteurized yogurt, sweet acidophilus milk, and cultured milk in lactase-deficient individuals (American Journal of Clinical Nutrition, 1984)
- Savaiano DA. Lactose digestion from yogurt: mechanism and relevance (American Journal of Clinical Nutrition, 2014)
- Shaukat A, et al. Systematic review: effective management strategies for lactose intolerance (Annals of Internal Medicine, 2010)
- Eating, Diet, and Nutrition for Lactose Intolerance (NIDDK)
- Definition and Facts for Lactose Intolerance (NIDDK)
