Most common mushrooms contain between 2 and 3 grams of protein per 100 grams (about 1.5 cups raw, sliced). That puts them on the lower end of protein sources overall, but notably higher than most vegetables. If you’re adding mushrooms to meals hoping for a protein boost, here’s what the numbers actually look like across varieties and what affects how much of that protein your body can use.
Protein Content by Variety
Not all mushrooms are created equal when it comes to protein. USDA data on raw mushrooms per 100 grams breaks down like this:
- White button: 3.0 g
- Oyster: 2.75 g
- Enoki: 2.66 g
- Lion’s mane: 2.5 g
- Maitake: 1.94 g
White button mushrooms, the most common variety in grocery stores, actually top this list. One cup of sliced white mushrooms (about 70 grams) gives you roughly 2.1 grams of protein with only about 15 calories. That’s a better protein-to-calorie ratio than many people expect from a fungus.
Dried mushrooms concentrate these numbers significantly because the water is removed. Since fresh mushrooms are roughly 90% water by weight, a 100-gram portion of dried mushrooms can contain 20 to 30 grams of protein depending on variety. Keep in mind you’d typically rehydrate them before cooking and use far less than 100 grams in a dish.
How Mushroom Protein Compares
To put those numbers in context: 100 grams of raw chicken breast has about 31 grams of protein, a large egg has around 6 grams, and 100 grams of cooked lentils provides roughly 9 grams. Mushrooms aren’t competing with any of these as a primary protein source. Where they shine is compared to other produce. Most raw vegetables deliver less than 2 grams of protein per 100 grams. Broccoli, one of the higher-protein vegetables, comes in at about 2.8 grams, putting it right alongside mushrooms.
If you’re eating mushrooms as a meat substitute in dishes like burgers or tacos, the protein gap is real. A portobello cap weighing around 85 grams has only about 2.5 grams of protein. You’d need to pair it with beans, grains, or another protein source to make the meal nutritionally comparable to one built around meat.
Amino Acid Quality
Protein isn’t just about quantity. Your body needs nine essential amino acids from food, and mushrooms do contain all of them, including leucine, lysine, and methionine. Research on both cultivated and wild species has found that the amino acid profile stays consistent within a given species regardless of where or how it grows. Soil type, tree cover, and other environmental conditions change total protein amounts but not which amino acids are present.
That said, mushrooms are relatively low in certain essential amino acids compared to animal proteins or legumes. They provide a broader amino acid range than most vegetables, but the total amounts per serving are small enough that mushrooms work best as one protein contributor among several in a meal rather than the sole source.
Cooking Matters for Absorption
Raw mushrooms present a problem your gut can’t easily solve. Mushroom cells are surrounded by walls made of chitin, the same tough material found in insect exoskeletons and crab shells. This chitin layer locks away protein and other nutrients, making them harder for your digestive system to access.
Cooking breaks down these cell walls and significantly improves how much protein your body actually absorbs. Research on king oyster mushrooms found that disrupting the cell wall structure, whether through heat or enzymatic treatments, effectively increased protein accessibility. In practical terms, this means sautéing, roasting, grilling, or even microwaving mushrooms isn’t just a taste preference. It’s a meaningful nutritional step. Eating raw mushrooms in a salad delivers less usable protein than the same mushrooms cooked.
Getting More Protein From Mushrooms
If you want to maximize the protein you get from mushrooms, a few strategies help. Choose white button or cremini mushrooms (which are actually the same species at different stages of maturity) since they sit at the higher end of the protein range. Cook them thoroughly. And use them in volume, since their low calorie density means you can eat a generous portion without much caloric cost.
A practical serving in most meals is about one cup cooked, which gives you roughly 2 to 3 grams of protein. That’s meaningful as part of a stir-fry with tofu, a grain bowl with beans, or an omelet. It’s not meaningful as a standalone protein source. Mushrooms are best understood as a protein supplement to a meal, not the foundation of one.