Which seeds have all 9 essential amino acids? A guide to plant-based complete proteins

October 31, 2025 •

4 min read

Although animal products are famously complete protein sources, a growing number of plant-based foods, including specific seeds and grains, provide all nine essential amino acids. Learning which seeds have all 9 essential amino acids is crucial for anyone seeking to diversify their protein intake and follow a vegan or vegetarian lifestyle without sacrificing nutritional completeness.

Quick Summary

Several plant foods, including hemp seeds, chia seeds, and the pseudocereal quinoa, contain all nine essential amino acids, making them complete protein sources. They are vital for plant-based diets and offer a range of other nutrients, like healthy fats and fiber. Combining different plant proteins throughout the day can also ensure a complete amino acid profile.

Key Points

Hemp Seeds: Provide about 10g of protein per 3 tablespoons and contain all nine essential amino acids, along with omega fatty acids and minerals.
Chia Seeds: A complete protein source, though with lower protein per serving than hemp, but very high in fiber and omega-3s, excellent for digestive health.
Quinoa: Technically a seed, this gluten-free pseudocereal is a complete protein, offering a great source of fiber, magnesium, and iron.
Combine Incomplete Proteins: You don't need all essential amino acids in one meal; combining foods like grains and legumes with other seeds throughout the day is an effective strategy.
Diverse Diet is Key: Relying on a variety of plant-based proteins, rather than a single source, ensures a balanced intake of all necessary nutrients over time.
Other Nutritious Seeds: Seeds like pumpkin, flax, and sunflower are not complete proteins on their own but offer significant nutritional value and can be combined to form a full amino acid profile.

Understanding Complete Proteins

Protein is a crucial macronutrient composed of building blocks called amino acids. Of the 20 different amino acids our bodies need, nine are classified as "essential" because the human body cannot produce them on its own. Therefore, these nine—histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine—must be obtained through diet. A "complete protein" source is one that provides all nine essential amino acids in sufficient amounts. While animal products are classic examples, the notion that plant proteins are universally incomplete is a myth, as several plant-based foods offer a full amino acid profile.

Seeds and Grains with a Complete Amino Acid Profile

Hemp Seeds: The Plant-Based Powerhouse

Hemp seeds are one of the most celebrated plant-based complete protein sources. A 3-tablespoon serving provides approximately 10 grams of protein and all nine essential amino acids. Beyond their robust protein content, hemp seeds are rich in omega-3 and omega-6 fatty acids in a ratio that is beneficial for heart health and inflammation reduction. They also offer an excellent source of minerals such as magnesium, iron, and zinc, making them a dense and versatile nutrient source. Hulled hemp seeds, or hemp hearts, are soft, nutty, and easy to add to a variety of meals, from smoothies and oatmeal to salads and baked goods.

Chia Seeds: The Hydrating Nutrient-Bomb

These tiny black seeds are packed with nutritional benefits and are another source of complete protein. Though they contain slightly lower protein per serving compared to hemp seeds, they are one of the richest plant-based sources of omega-3 fatty acids. Chia seeds are also exceptionally high in fiber, which promotes satiety, aids digestion, and helps regulate blood sugar levels. When soaked in liquid, they expand to form a gel-like consistency, making them a popular addition to puddings, jams, and overnight oats.

Quinoa: The Versatile Pseudocereal

Often mistaken for a grain, quinoa is technically a seed and a fantastic source of complete protein. Cooked quinoa offers about 8 grams of protein per cup and contains a higher amount of lysine than many other grains. This gluten-free option is also a great source of fiber and minerals like manganese, magnesium, and iron. Quinoa's mild, nutty flavor makes it a versatile ingredient that can replace rice, form the base of salads and bowls, or be cooked into a hot breakfast porridge.

Complete Protein Seeds: A Nutritional Snapshot


Seed/Grain	Protein (per oz/28g)	Omega-3s	Key Nutrients	Notes
Hemp Seeds	~10g (hulled)	Excellent	Magnesium, Iron, Zinc	Most complete EAA profile; nutty flavor
Chia Seeds	~5g	Excellent (ALA)	Calcium, Manganese, Fiber	Absorbs liquid to form a gel; very high in fiber
Quinoa	~8g (per cooked cup)	Minor	Magnesium, Iron, Zinc	Pseudocereal, gluten-free, versatile

Beyond the 'Complete' List: The Power of Combining Proteins

While hemp, chia, and quinoa are standout complete proteins, it's important to remember that you don't need to consume a complete protein source at every meal. The body stores and recycles amino acids throughout the day. Therefore, consuming a variety of plant-based protein sources will provide all the essential amino acids over time. Other seeds, while not complete on their own, are still incredibly nutritious and can be combined with other foods to form a complete profile. For example:

Pumpkin seeds: A very good source of protein, rich in magnesium, iron, and zinc. They are a great topping for salads or soups.
Flaxseeds: Known for their dietary fiber and omega-3 fatty acids (ALA) content. Best consumed ground for optimal nutrient absorption.
Sesame seeds: A high source of calcium and other minerals. They can be ground into tahini or sprinkled over stir-fries.
Sunflower seeds: Rich in Vitamin E, a potent antioxidant, and offer a nutty flavor perfect for trail mixes.

A simple strategy is to combine grains (like brown rice) with legumes (like beans or lentils) and seeds for a complete meal. Examples include a bowl of brown rice with black beans and sprinkled hemp seeds, or whole-wheat toast with mashed chickpeas and sunflower seeds.

How to Incorporate Complete Protein Seeds

These nutrient-rich seeds can be easily integrated into your daily diet. Here are some simple ideas:

Breakfast Boost: Stir hemp or chia seeds into your morning oatmeal, yogurt, or smoothie for a protein and fiber boost.
Salad Topping: Sprinkle raw or lightly toasted hemp, chia, or pumpkin seeds over salads for added crunch and nutrition.
Baking: Mix ground flaxseeds or chia seeds into muffins, breads, or cookies.
Homemade Dressings: Blend seeds or nut butters into salad dressings for a creamy, nutrient-rich base.
Meal Base: Use cooked quinoa as a base for hearty bowls with roasted vegetables, legumes, and a flavorful dressing.
Seed Cycling: Rotate flax and sesame seeds or pumpkin and sunflower seeds throughout the month for a variety of nutrients and potential hormonal benefits.

Conclusion: Beyond a Single Source

While hemp seeds, chia seeds, and quinoa stand out as complete protein sources among plant foods, a balanced and varied diet is the key to ensuring adequate amino acid intake. Instead of focusing solely on these single "complete" sources, embracing a wide range of plant-based foods—combining grains, legumes, nuts, and seeds—will provide a robust and healthy nutritional profile. Whether you're a long-time vegan or simply aiming to increase your plant-based protein consumption, these seeds and grains are valuable, versatile additions to your pantry.

For more information on balancing plant-based diets, consult resources like the Harvard T.H. Chan School of Public Health.

Frequently Asked Questions

Yes, hemp seeds are a complete protein source because they contain all nine essential amino acids that the human body needs but cannot produce on its own.

Both chia and hemp seeds are complete proteins. However, hemp seeds offer a higher protein content per serving, while chia seeds are an excellent source of fiber and omega-3 fatty acids.

Pumpkin seeds contain all nine essential amino acids but are typically considered an incomplete protein because their amino acid lysine content is too low to be considered a complete source on its own.

No, it is not necessary to combine incomplete proteins within the same meal. The body stores amino acids in a pool throughout the day, so consuming a variety of plant proteins over the course of a day is sufficient.

Like many seeds, most nuts are not complete protein sources on their own, with the exception of pistachios, which have been classified as a complete protein. Other nuts can be combined with legumes or grains to create a complete profile.

Vegans can obtain all essential amino acids by consuming a variety of protein-rich plant foods like tofu, tempeh, edamame, and whole foods combinations like lentils with grains or hummus with whole-wheat bread. Focusing on naturally complete plant proteins such as hemp seeds, chia seeds, and quinoa is also effective.

Soaking, sprouting, or grinding seeds can improve digestibility and nutrient absorption. Grinding flaxseeds, for instance, is recommended for better omega-3 and fiber absorption.