Pea Protein Vs Rice Protein: The Ultimate Comparison Guide

A comprehensive comparison of pea protein and rice protein, looking at amino acid profiles, muscle growth, taste, and which is truly healthier. Find out why a blend might be the best option.

Plant-based diets have exploded in popularity, driving demand for high-quality vegan protein sources. With global meat demand expected to rise by at least 50 percent by 2050, ^[1] alternative proteins use a fraction of the land and water required by conventional meat, generate fewer greenhouse gases, and reduce the flow of pollutants into communities and ecosystems. ^[2]

Among plant proteins, two contenders have emerged as frontrunners – pea protein and rice protein. These are two of the most popular plant based protein sources backed by solid science. But which one deserves a spot in your shake?

This analysis cuts through the marketing hype to examine amino acid profiles, muscle-building potential, digestibility, taste, and environmental impact. The goal = giving you the facts to make the best choice for your health and fitness goals.

What is Pea Protein?

Pea protein powder is a high-quality, easily digested protein source made from yellow peas. The process involves removing shells, milling peas into flour, then filtering out starches and sugars to isolate the protein. The result? A beige powder containing roughly 80% protein.

Nutritional Profile & Benefits

Pea protein is high in lysine and contains impressive amounts of branched-chain amino acids. Pea protein isolate contains 85% of proteins and is particularly rich in essential branched-chain amino acids (BCAA; leucine, isoleucine and valine) known to play an important role in muscle protein synthesis.

Here’s where pea protein stumbles. It only has very small amounts of methionine, one of the essential nine. This amino acid plays a critical role in metabolism and protein synthesis.

✅ Key Benefits

• Muscle Growth: The high BCAA content gives pea protein serious muscle-building credentials. A 12-week study found that males who consumed 50 grams of pea protein per day gained the same amount of muscle as those taking whey protein. Not bad for a plant protein. ^[4]
• Rich in Iron: Pea protein powders are rich in iron. Most products contain around 5–7.5 mg of iron per serving – roughly 28–42% of the reference daily intake for premenopausal women and 62–94% of the RDI for men and postmenopausal women. For vegans prone to iron deficiency, this is a game-changer.
• Supports Satiety: A 2022 study found that pea protein powder is just as effective at promoting fullness as dairy-based protein powders like casein or whey = it helps you feel fuller for longer. ^[5]

🤔 Potential Downsides:

• Some users report an earthy taste and thicker texture. You can compensate for pea protein’s “slightly dirt-like” flavor by adding in other ingredients like fruit, veggies, and nut butters. I personally find that it pairs extremely well with bananas.

What is Rice Protein?

Rice protein is typically made by treating brown rice with select enzymes that cause the carbohydrates and protein to separate. The protein can be isolated, resulting in a high quality, plant-based protein powder. When made from sprouted brown rice, it offers additional benefits from the sprouting process.

Nutritional Profile & Benefits

Rice protein is high in methionine (promotes detoxification and muscle contraction) and the semi-essential amino acid cysteine.

While it is technically a source of complete protein (contains all amino acids needed by the body), it is lower in the amino acid lysine compared to whey protein. This limits its muscle-building potential when used alone.

The biological value sits at 81, indicating good protein utilization.

“Biological Value? What’s that?”

✅ Key Benefits:

• Free from allergens: Rice protein is free from top 9 allergens and easily digestible, making it suitable for those with food sensitivities or intolerances. If you’re dealing with multiple food allergies, rice protein is often the safest bet.
• Gentle on Digestion: With most of the starch and fiber removed rice protein is easily digested and absorbed, making it a good choice for those with digestive issues. No bloating, no gas—just smooth digestion.
• Complements Pea Protein: This is where rice protein truly shines. What rice protein lacks in amino acids, pea protein makes up when paired together. The two proteins create a synergistic effect.

🤔 Potential Downsides:

• Rice protein can have a gritty texture and, when used alone, lacks sufficient lysine for optimal muscle building.

So, Which Protein is Better?

Neither protein wins universally. The “healthier” choice depends on your goals and physiology.

For Muscle Health & Performance: Pea Protein

The International Society of Sports Nutrition suggests that the optimal amount of leucine for muscle growth is between 0.7 grams and 3 grams per serving.

Whey has 105 mg of leucine per gram of protein, while pea protein contains about 81 mg of leucine per gram. Rice protein falls further behind with even lower leucine content.

While that’s a 25% difference between whey and pea, studies show that pea protein supports muscle growth just as well as whey protein, making it the superior choice over rice protein for muscle-building goals.

For Digestive Health & Allergen Avoidance: Rice Protein

Pea protein is generally easier on the stomach and less likely to cause digestive discomfort, making it a favorable option for individuals who experience bloating or gas with whey protein.

But rice protein takes this further – it’s practically bulletproof for sensitive digestive systems.

You see, rice protein is considered “bulletproof” for sensitive digestive systems because with most of the starch and fiber removed rice protein is easily digested and absorbed, making it a good choice for those with digestive issues.

Unlike pea protein, which can occasionally cause gas in some users, rice protein is hypoallergenic, gluten-free, and free from top 9 allergens (Milk/Dairy, Eggs, Peanuts, Tree nuts, Soy, Fish, Shellfish, Wheat, Sesame) and easily digestible, making it suitable for those with food sensitivities or intolerances.

The processing removes the compounds that typically cause digestive distress, and rice protein’s gentleness is so well-established that it’s even used in baby food and supplements as filler.

For Micronutrient Density: Pea Protein

The iron content alone makes pea protein superior for preventing deficiencies. Legumes, including peas, are a great source of the nutrient. This matters especially for women and vegans.

For Less Heavy Metals: Pea Protein

Here’s where things get serious. Rice plants, due to their physiology and growing conditions, accumulate 10 times more arsenic than other grain crops. ^[7] (Brown rice has been shown to contain higher concentrations of arsenic and other pesticide contaminants compared to white rice ^[8]).

Arsenic is a poisonous chemical that occurs naturally in soil and water, but pollution has made levels much higher in many places. When you consume arsenic regularly over time, it can cause cancer, heart problems, and other serious health issues—that’s why the EPA calls it a carcinogen.

A 2025 report found arsenic in 100% of 145 rice samples purchased from stores across the U.S., with one in four rice samples exceeding the federal limit of 100 parts per billion of inorganic arsenic. ^[9] It is worth noting that The Environmental Protection Agency has labeled inorganic arsenic a carcinogen. ^[10]

The arsenic contamination in rice protein creates a real safety concern. While rice protein can be safe when properly tested, choosing products from reputable brands that conduct third-party heavy metal testing becomes non-negotiable—not optional.

Pea protein sidesteps this entire issue. It generally carries much lower heavy metal risks while still delivering superior nutrition. In fact, pea protein (along with hemp and pumpkin seed proteins) contains 200-400% more arginine than whey protein isolate, supporting healthy blood flow and heart health.

Bottom Line: Pea protein edges out rice protein on pure health metrics, but the heavy metal issue in untested rice protein creates a significant safety gap.

For Less Environmental Footprint: Pea Protein

Pea Protein: Peas and other legumes enrich soil, rather than deplete it, through the process of nitrogen fixation. The roots of the pea plant convert nitrogen in the air to a form plants can use, reducing the need for nitrogen-based fertilizers. Peas have a shallow root system and are one of the lowest water consumers.

Rice Protein: Every kilogram of rice requires 2,250 liters of water. Rice cultivation is notoriously water-intensive and can have a higher carbon footprint than pea production.

Cost Comparison: Same

To compare actual prices, I went to iHerb and researched current market rates for both proteins:

The pricing varies significantly by brand rather than protein type. NOW Foods actually prices rice protein lower than pea, while Nutricost charges €15 more for organic rice protein. NutriBiotic keeps both proteins competitively priced within €1.50 of each other.

Bottom line: Price differences are brand-specific, not protein-specific. Both remain more affordable than premium whey isolates, typically ranging €27-46 for 600-900g depending on brand and organic certification.

Best For Taste: Rice Protein

Pea Protein: The earthier flavor works better in savory applications like soups or vegan “meat” products. In smoothies, strong-flavored add-ins help mask the taste.

Rice Protein: Rice protein powder is often described as mild and neutral in taste, making it versatile for various recipes and smoothies. It’s ideal for baking and protein bars where you want the protein to disappear flavor-wise.

The “Better Together” Solution

Combining pea and rice proteins makes up a more balanced amino acid composition. Pea protein lacks methionine but contains adequate lysine. Brown rice protein is the opposite. It contains high amounts of methionine but not enough lysine. When combined, they help fill in each other’s gaps to form a complete protein.

The math is simple: pea protein’s lysine + rice protein’s methionine = complete amino acid profile rivaling whey.

The two plant proteins therefore complement each other perfectly. A 50/50 blend delivers the muscle-building BCAAs from pea protein while providing the digestive gentleness and methionine from rice protein. Plus, blending reduces your exposure to any single source’s potential contaminants.

The combo also improves taste. Combining the two proteins also improves the flavor compared to pea protein on its own.

The Final Verdict

Both proteins bring unique strengths to the table. Pea protein delivers superior muscle-building BCAAs, higher iron content, and better environmental credentials. Rice protein offers unmatched digestibility, allergen-friendliness, and taste versatility.

But using either protein alone means accepting compromises. The smart money is on combining them. Proteins from rice and peas complement each other perfectly and are therefore often combined.

A quality pea-rice blend gives you complete amino acid coverage, balanced nutrition, and reduced risks associated with single-source proteins. It’s the closest you’ll get to whey’s benefits while staying completely plant-based.

The bottom line? While each protein has merit individually, the combination approach offers the most complete, balanced, and effective plant-based protein solution available today. That’s not marketing speak—it’s just smart nutrition.

(Ed. note: Always verify that any rice protein product you purchase has been third-party tested for heavy metals, regardless of organic certification.)