Skyr: What It Is, Nutrition, Protein and How It Compares

Skyr (say “skeer”) is a thick, tangy cultured dairy food from Iceland. It is eaten with a spoon like yogurt, and US stores shelve it next to yogurt, often as “Icelandic yogurt”, but Icelandic food scientists class it as a fresh cheese made from skimmed milk. Straining away much of the whey is what makes skyr so dense and high in protein per spoonful. One detail matters for anyone comparing numbers: the USDA SR Legacy database, the reference behind most nutrition tables, has no entry for skyr. This guide explains what skyr is, how skyr nutrition and skyr protein compare with the dairy foods USDA does list, how skyr vs Greek yogurt plays out, and what to check on the label.

Peptide Labs does not sell skyr or dairy foods. This article is general nutrition information, not medical advice.

What is skyr?

Skyr is a traditional Icelandic food, one of the staples analysed for Iceland’s food composition database, and it is now also made abroad; a 2022 Brazilian consumer study described shoppers there as still unfamiliar with it. The basic method is simple. Skimmed milk is pasteurized, cultured with lactic acid bacteria until it thickens and sours, and then strained so that liquid whey drains off. What stays behind is a very thick, mild, slightly sour curd that is low in fat when it starts from skim milk.

A 2011 analysis of typical Icelandic foods, carried out to update Iceland’s food composition database, classed skyr as a fresh cheese. It found skyr rich in protein, calcium and phosphorus, and noted that skyr keeps almost all of the selenium in the skimmed milk used to make it. The whey drained from skyr turned out to be mineral-rich too, which shows that straining moves some nutrients into the liquid that is removed.

In US supermarkets, the word “skyr” is a style name, not a federally defined product. The federal yogurt standard (21 CFR 131.200) does not mention skyr, Greek style or straining, so recipes differ from brand to brand. A 2025 lab study of skyr-type yogurts, for example, measured noticeably less protein than many commercial cups list, which is a reminder to read each label rather than assume.

Skyr nutrition and protein: what USDA does and does not list

We use the USDA FoodData Central SR Legacy database for every food guide on this site. It has no entry for skyr, so there is no USDA value to quote for skyr calories, skyr protein or calcium. The closest entries are plain strained (Greek-style) yogurts, which are made the same basic way. The table puts them next to regular plain yogurt and lowfat cottage cheese, per 170 grams (a common 6-ounce cup), so you can see what straining does. Read the strained yogurt rows as a stand-in, not as skyr.

Two patterns stand out in the USDA rows. First, the strained nonfat yogurt has close to twice the protein of regular skim yogurt per 170 grams, with less than half the sugar, because straining concentrates the milk protein and drains off some lactose with the whey. Second, the regular yogurt has more calcium per cup. Harvard’s Nutrition Source notes that some calcium is removed during straining, and the USDA numbers fit that pattern. The nonfat strained entry also supplies about 53% of the Daily Value for vitamin B12 and 36% for riboflavin per 170 grams; our B12 foods guide covers other sources.

For skyr itself, the label is the source of truth. Check the Nutrition Facts panel for protein, total and added sugars, fat and calcium per serving, and note the serving size, since cups vary.

Skyr vs Greek yogurt

This is the comparison most shoppers are making in the dairy aisle. Both are cultured milk products strained until thick, both are high in protein for their calories when plain, and both come in nonfat, lowfat and whole-milk versions. Our Greek yogurt guide covers that product in depth. The practical differences are smaller than marketing suggests:

• Starting milk: traditional skyr starts from skimmed milk, so classic plain skyr is nonfat or close to it. Strained yogurt is sold at every fat level; check the fat line on any skyr cup, since recipes vary.
• Texture and taste: both are thick and tangy, and thickness and sourness vary by brand more than by style name, so compare plain versions side by side.
• Protein and sugar: per gram, plain versions of both tend to land in a similar range. Compare labels at the same serving size rather than by the style name.
• Regulation: neither “skyr” nor “Greek” is defined in the federal yogurt standard, so there is no legal minimum protein for either term.

Cottage cheese is the other common high-protein dairy option; our cottage cheese guide explains why it usually carries far more sodium than plain strained yogurt, as the table shows. Kefir is a thinner, drinkable cultured milk; see our kefir guide.

Live cultures, lactose and labels

Skyr is a fermented dairy food, so it usually contains live bacteria when it leaves the plant. For products sold as yogurt, the federal standard lets the label say “contains live and active cultures” when the culture count meets an FDA minimum, and requires “does not contain live and active cultures” if the product was heated after culturing to inactivate the bacteria. Having live cultures is not the same as having a studied probiotic strain at a known amount; our guide to choosing a probiotic and fermented foods guide explain the difference.

For lactose, the NIDDK lists yogurt among the dairy foods that many people with lactose intolerance handle better, and research reviews report that the bacteria in yogurt help digest its lactose. Straining also leaves less sugar in the cup, as the USDA rows show. Skyr is not lactose free unless the label says so; our lactase guide covers lactase enzyme products, and a clinician can help sort out symptoms.

How to eat skyr, and who should be careful

• Eat it plain with fruit and nuts, or use it in place of sour cream in dips and sauces.
• Flavored cups can carry added sugar; check the Added Sugars line.
• Stir it into overnight oats or blend it into smoothies for a thicker texture.
• Keep it refrigerated and follow the date on the cup.

Milk is one of the nine major food allergens under US law, so skyr is not suitable for anyone with a milk allergy; if you choose a plant-based alternative, read its allergen statement. If you suspect a food reaction, an allergist can test properly, and our elimination diet guide explains why self-testing at home has limits. For broader context on calcium and protein foods, see our guides to calcium in foods and protein-rich foods, and for a different grab-and-go dairy option, our string cheese guide.

Frequently Asked Questions

Questions about a label? Contact us or read our Buyer’s Guide. Food comes first; follow the label and ask a healthcare provider before starting a supplement, especially if you take medicines, are pregnant or have a food allergy. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Last reviewed October 2026.

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