Does Barley Contain Protein?

When people think of high-protein grains, quinoa and oats usually get the spotlight. Barley, that chewy grain in soups and salads, often gets overlooked. It doesn’t advertise its protein content the way trendy grains do, so the question sneaks in: does barley contain protein worth counting?

The short answer is yes — barley does hold a respectable amount of protein. Hulled barley delivers roughly 12.5 grams per 100-gram serving uncooked, which puts it in the conversation with other whole grains. However, there’s an important catch. Barley is not a complete protein, meaning it lacks enough of the essential amino acid lysine. Here’s what that means for your diet and how to work around it.

How Much Protein Does Barley Actually Have?

Per the USDA nutrition database, hulled barley — the least processed form — provides about 12.5 grams of protein per 100-gram uncooked weight. That’s roughly the same amount of protein you would get from a hard-boiled egg in a small portion of dry grain. Cooked barley drops down to around 3.6 grams per cup, still a meaningful contribution to a meal.

To put that in context, barley comes in ahead of white rice (about 2.7 grams per cooked cup) and corn (about 3.4 grams per cup), but behind quinoa (roughly 8 grams per cooked cup). Oats, another popular breakfast grain, offer around 5–6 grams per cooked cup. So barley holds its own among grains, especially considering its fiber content.

Exact protein depends on the variety. Hulled barley, which retains the bran and germ, naturally has more protein than pearled barley, where the outer layers are polished off. Pearled barley still provides protein but in lower amounts.

Why Barley’s Protein Falls Short

Despite a decent protein count, barley has a limitation that matters if you rely on it as a primary protein source. Like most grains, it’s low in the essential amino acid lysine. Lysine is needed for collagen production, calcium absorption, and making carnitine. Without enough lysine, your body cannot use the protein quite as efficiently.

• Lysine deficiency: Barley provides very little lysine compared to animal foods or legumes, which is why it is considered an incomplete protein.
• Less balanced amino acid pattern: A peer-reviewed study found that the gastrointestinal digest of barley protein has a less balanced amino acid pattern compared to quinoa protein, meaning the full protein value is not as available.
• BCAA content is lower: Oats, corn, and millet contain higher amounts of total branched-chain amino acids (BCAAs) than barley, per a grain comparison analysis.
• Not a stand-alone source: If you are eating a vegetarian or vegan diet, you cannot rely on barley alone to meet all essential amino acid needs.
• Pairing solves the problem: The good news is that lysine is abundant in many plant foods, making it easy to complement barley.

The takeaway is not that barley is a poor choice — just that it works best as part of a varied diet. When you pair it with foods rich in lysine, like beans, lentils, nuts, or animal proteins, you get the full amino acid profile your body needs.

How Barley Protein Compares to Other Grains

To see where barley fits in the grain protein hierarchy, it helps to line up the numbers side by side. The table below shows approximate protein content per 100 grams of uncooked hulled grain, based on USDA estimates.

As the table shows, barley sits in the middle range among grains. It is competitive compared to rice and corn but significantly behind quinoa and amaranth, which are complete proteins. Healthline’s Barley Protein Content page corroborates these ranges and adds that barley also provides notable fiber and B vitamins.

The key difference is that quinoa contains all nine essential amino acids in adequate amounts, while barley does not. For someone eating a variety of grains over the day, that is less of a concern — but for anyone optimizing plant-based protein intake, it is worth noting.

How to Make Barley a Complete Protein

You do not have to eat barley alone to get complete protein. A simple pairing strategy fills the lysine gap without much effort.

1. Pair barley with legumes: Lentils, chickpeas, black beans, or split peas supply plenty of lysine. A barley-lentil soup or barley salad with chickpeas creates a complete amino acid profile.
2. Add nuts or seeds: Pumpkin seeds, almonds, or sunflower seeds are rich in lysine. Sprinkle them over cooked barley or mix into a pilaf.
3. Include animal protein: If you are not plant-based, adding chicken, fish, eggs, or yogurt to a barley bowl easily rounds out the protein.
4. Combine with other grains: While not ideal, mixing barley with small amounts of amaranth or quinoa can boost lysine.

The concept of protein complementing is well-established, though modern nutrition science notes that eating a variety of proteins throughout the day works just as well as perfect pairing at every meal. Barley’s 3–4 grams of protein per cooked cup becomes more valuable with these additions.

What About Barley’s Other Nutritional Strengths?

Even with the protein caveat, barley brings a lot to the table nutritionally. Its real star is fiber — specifically beta-glucans, a type of soluble fiber linked to heart health and blood sugar regulation. A 100-gram serving of hulled barley provides over 17 grams of fiber, more than many other grains.

Barley is also a good source of B vitamins. It provides 43% of the Reference Daily Intake for thiamine (B1) and has five times more niacin (B3) than quinoa. These vitamins support energy metabolism and nervous system function. A peer-reviewed study in PubMed notes that barley lacks lysine, but also confirms its overall protein content and digestibility remain useful in grain-based diets.

Mineral-wise, cooked barley contains about 153 mg of potassium per cup and decent amounts of magnesium, phosphorus, and selenium. For anyone looking to increase fiber and B vitamins while adding moderate protein, barley is a practical choice.

The Bottom Line

Barley does contain protein — about 12.5 grams per 100 grams uncooked — but it is not a complete source due to low lysine. For most people eating a varied diet, that is not a problem. Pair it with legumes, nuts, or animal protein to cover all essential amino acids. When it comes to fiber and B vitamins, barley surpasses many grains.

If you are tracking protein for muscle gain or managing a condition that requires careful protein intake, a registered dietitian can help you fit barley into your overall plan and balance it with other sources to meet your complete amino acid needs.