Pea Protein vs Whey Protein: What Studies Show

At matched doses, pea protein and whey produced similar muscle and strength gains in head-to-head trials. In a 12-week trial of 161 men, neither beat the other for biceps thickness¹. Pooled data show a small edge for animal protein in younger adults². Pick pea if you avoid dairy, and whey if you tolerate it.

This page compares the two powders directly. For each one on its own, see our pea protein and whey protein pages.

Yes. In every head-to-head trial we found that measured muscle or strength, pea protein performed about as well as whey.

• 12 weeks, 161 men aged 18-35: 25 g of pea protein, whey or placebo twice a day alongside biceps training. Group differences in biceps thickness were only a trend (P = 0.09) and strength did not differ¹.
• In a post-hoc analysis of the weakest starters (the overall result was not significant): thickness rose 20.2% with pea, 15.6% with whey and 8.6% with placebo. Pea beat placebo, while whey did not differ from either¹.
• 84 days, sedentary adults: pea and whey did not differ for strength, muscle mass or likability. Whole-body strength rose 16.1% with pea (p = 0.01) and 11.1% with whey (p = 0.06)³.
• 8 weeks, 15 people doing high-intensity functional training: 24 g before and after exercise gave no group differences. It is a small pilot, so it cannot rule out a modest gap⁴.
• One 30 g dose, 24 young men: muscle protein synthesis was 0.053%/h after pea and 0.053%/h after milk protein (P = 0.96)⁵.

Muscle protein synthesis is how fast the body builds new muscle protein. Our muscle protein synthesis page covers it, with pea protein and whey protein each rated for it.

What do the meta-analyses say?

• Plant vs animal protein, 2025 (43 trials, 30 pooled): plant protein gave slightly less muscle mass (SMD -0.20; 95% CI -0.37 to -0.03). Strength did not differ (14 trials)⁶.
• Soy vs milk protein in that review (17 trials): no difference for muscle mass (SMD -0.02). Plant proteins other than soy, namely rice, chia, oat and potato, did worse than animal protein (SMD -0.58)⁶.
• Animal vs plant protein, 2021 (16 trials): source did not change absolute lean mass or strength. Adults under 50 gained 0.41 kg more lean mass with animal protein (95% CI 0.08 to 0.74)².
• Acute response, 2026 network meta-analysis (51 trials): native whey (P-score 0.81) and pea (0.77) ranked highest. Only conventional whey protein reached statistical significance, and certainty was low to moderate⁷.

The takeaway is cautious. The network meta-analysis authors advise that protein sources represented by few studies be interpreted with caution⁷. Our summaries of the 161-man trial and the 2021 meta-analysis have the full numbers.

Does either work better in older adults?

• 31 men aged about 72, 8 days: an extra 50 g a day of whey or pea raised muscle protein synthesis from 1.46 to 1.59%/day. Collagen did not⁸.
• 27 adults aged 50-70, 10 days: diets with 1.0 g/kg of protein from whey-supplemented or pea-supplemented sources gave the same rates of muscle protein synthesis⁹.
• Across the 30 trials pooled for muscle mass: the plant-protein gap was clearer in adults under 60 (SMD -0.20) than in adults 60 and older (SMD -0.05; 95% CI -0.32 to 0.23, not significant)⁶.

Whey lowered a muscle damage marker in one small trial of older adults, but it did not significantly beat pea in a larger trial, and neither powder reduced soreness.

• 92 men, 5 days after a 90-minute eccentric workout: whey lowered damage markers versus water (Cohen's d above 0.80). Pea had an intermediate, non-significant effect (d below 0.50), and whey and pea did not differ significantly. Soreness was unchanged by either¹⁰.
• 47 active adults aged 60 and over, 13 days at 25 g/day: 24 hours after a 20-30 km walk, creatine kinase was 175 with whey, 300 with pea and 330 with placebo (P < 0.001). Strength, muscle mass and soreness did not differ¹¹.

For recovery after hard efforts, the evidence leans only slightly toward whey. See our guide on when to take whey protein and the post-workout recovery page.

Whey delivers more essential amino acids into the blood than pea^{12, 13}. In a trial comparing pea with milk protein at 30 g, that gap did not change muscle protein synthesis⁵.

• Composition: indispensable amino acids made up 58% of whey isolate and 46% of pea isolate. In one trial of 9 men given 0.33 g/kg, the rise in total indispensable amino acids was 41% greater for whey (p < 0.001)¹⁴.
• 25 g meals, 20 adults: pea concentrate, isolate and extruded pea all gave lower plasma essential amino acids than whey (P < 0.001). Extruded pea was also delayed¹².
• 0.3 g/kg, 10 adults: essential amino acids were higher after whey than pea, and adding rice protein did not close the gap¹³.
• Pea vs milk protein, 30 g: milk raised essential amino acids more (151 vs 102 area units, P < 0.001), yet muscle protein synthesis matched⁵.

Is pea protein a complete protein?

Pea isolate supplies all nine essential amino acids. In 15 volunteers, its digestible indispensable amino acid score (DIAAS) was 1.00, meaning it met every requirement, versus 1.45 for casein¹⁵. Total digestibility was 93.6% for pea and 96.8% for casein, which was not a significant difference. Leucine, valine, lysine and phenylalanine were less digestible in pea¹⁵. That trial used casein, a milk protein, not whey, so it shows quality but not a whey comparison.

The fullness trials found no difference between pea and whey, and we found no long-term weight-loss trial that compared them.

• 30 men (15 young, 15 older), 40 g breakfast drinks: protein source had no effect on plasma appetite markers, food intake or energy expenditure, although the abstract also reports a protein-source effect on appetite ratings¹⁶.
• 10 adults, 0.3 g/kg: ghrelin, GLP-1, appetite ratings and buffet intake did not differ between pea and whey¹³.
• 20 adults, 25 g: satiety ratings were comparable¹².

These were single-meal trials, so they say little about weeks of dieting. Our weight loss support and appetite regulation pages cover the wider evidence, including whey protein for weight loss support.

Pea protein's main drawbacks are a smaller amino acid surge, a possible allergy, and metals that vary by product.

• Amino acids: lower blood essential amino acids than whey, as above^{12, 14}.
• Allergy: pea is among "nonpriority" legumes frequently implicated in severe allergic reactions. A scoping review found 47 eligible studies, mostly on prevalence¹⁷. A US case series described children reacting to foods containing pea protein¹⁸. Pea is not one of the nine major allergens the law requires labels to declare¹⁹.
• Metals (plant-based powders, not pea alone): 56 plant-based protein powders contained on average lead (0.07 mg/kg), cadmium (0.09 mg/kg) and aluminum (18.39 mg/kg). At 30 g/day, exposure stayed within reference limits²⁰.
• Likability: in the 84-day trial, product perception and likability scores did not differ between pea and whey³.

Most of the caution is about dairy, kidneys and contamination, and the trial evidence for harm in healthy adults is weak.

• Lactose: about 36% of people in the United States have lactose malabsorption, though most can handle some lactose²¹. See lactose intolerance.
• Milk allergy: milk is a major food allergen that labels must declare¹⁹.
• Kidneys and liver: a systematic review of 11 papers linked harm mostly to chronic, excessive use, with the kidneys and liver most affected²². In a 10-day trial of 27 adults, renal function did not change on whey-supplemented or pea-supplemented diets⁹. If you have chronic kidney disease, ask your clinician before using any protein powder.
• Acne: the systematic review above linked whey to acne, but in a 6-month trial of 49 men with acne, 30 g/day of whey did not worsen total lesions (mean difference -5.99; 95% CI -13.18 to 1.19)²³. See acne.
• Metals: in 47 whey powders, 30-100 g/day for 25 years gave a hazard index below one. At 100 g/day with the highest concentrations, chromium, zinc, iron, molybdenum and magnesium intakes exceeded recommended intakes²⁴.

People allergic to peas or other legumes should avoid pea protein, and everyone else should keep daily intake near label servings.

Is pea protein safe to consume daily?

In the 84-day trial, both pea and whey were safe and well tolerated in healthy sedentary adults³. At 30 g/day, mineral and metal exposure from plant-based powders stayed within reference intakes. At 100 g/day, intakes exceeded the adequate intake for copper (105%) and magnesium (106%) in women, and for molybdenum (250%) and iron (121%) in men and postmenopausal women²⁰.

• Peas or legumes allergy: avoid pea protein and check labels. See food allergies¹⁷.
• Milk allergy: avoid whey¹⁹.
• Kidney or liver disease: talk to your clinician first²².

Choose by tolerance and diet first, because the muscle results are similar at the same dose.

• You avoid dairy or eat vegan: pea. A trial of 25 g twice a day showed gains like whey¹.
• You tolerate dairy and want more trials behind your choice: whey. In the acute-response network meta-analysis only conventional whey reached statistical significance, although pea ranked similarly⁷.
• You are lactose intolerant: pea contains no lactose, though many people with lactose intolerance tolerate small amounts²¹.
• You react to peas or legumes: whey¹⁷.
• You are older and recovering from hard efforts: either supported muscle protein synthesis similarly^{8, 9}, but only whey lowered the damage marker¹¹.
• You are dieting: either; fullness was similar¹⁶.

Match grams, not scoops: the trials used 24-30 g per serving^{4, 5}. For a slower milk protein, see casein vs whey and the casein protein page.

Supplements in this guide

• Pea Protein
• Whey Protein
• Casein Protein

We searched the research literature indexed from PubMed on pea vs whey for muscle, absorption, fullness and safety. We read the abstracts and reported statistics of 22 papers and two government pages, and cite all of them. We prioritized head-to-head trials and systematic reviews. Most trials were in young men and several were small, and we did not read full texts. No long-term weight-loss trial compared the two. Last researched 2 November 2026.

1. Babault N, et al. Pea proteins oral supplementation promotes muscle thickness gains during resistance training: a double-blind, randomized, Placebo-controlled clinical trial vs. Whey protein. J Int Soc Sports Nutr. 2015;12(1):3. doi:10.1186/s12970-014-0064-5 Our study summary.
2. Lim MT, et al. Animal Protein versus Plant Protein in Supporting Lean Mass and Muscle Strength: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Nutrients. 2021;13(2). doi:10.3390/nu13020661 Our study summary.
3. Singh RG, et al. Efficacy of Pea Protein Supplementation in Combination with a Resistance Training Program on Muscle Performance in a Sedentary Adult Population: A Randomized, Comparator-Controlled, Parallel Clinical Trial. Nutrients. 2024;16(13). doi:10.3390/nu16132017
4. Banaszek A, et al. The Effects of Whey vs. Pea Protein on Physical Adaptations Following 8-Weeks of High-Intensity Functional Training (HIFT): A Pilot Study. Sports (Basel). 2019;7(1). doi:10.3390/sports7010012 Our study summary.
5. Pinckaers PJM, et al. Post-prandial muscle protein synthesis rates following the ingestion of pea-derived protein do not differ from ingesting an equivalent amount of milk-derived protein in healthy, young males. Eur J Nutr. 2024;63(3):893-904. doi:10.1007/s00394-023-03295-6
6. Reid-McCann RJ, et al. Effect of Plant Versus Animal Protein on Muscle Mass, Strength, Physical Performance, and Sarcopenia: A Systematic Review and Meta-analysis of Randomized Controlled Trials. Nutr Rev. 2025;83(7):e1581-e1603. doi:10.1093/nutrit/nuae200
7. Bischof K, et al. Impact of different protein sources on acute muscle protein synthesis following resistance training: a systematic review with standard and dose-response network meta-analyses. J Int Soc Sports Nutr. 2026;23(1):2740224. doi:10.1080/15502783.2026.2740224
8. McKendry J, et al. The effects of whey, pea, and collagen protein supplementation beyond the recommended dietary allowance on integrated myofibrillar protein synthetic rates in older males: a randomized controlled trial. Am J Clin Nutr. 2024;120(1):34-46. doi:10.1016/j.ajcnut.2024.05.009
9. Korzepa M, et al. Resistance training increases myofibrillar protein synthesis in middle-to-older aged adults consuming a typical diet with no influence of protein source: a randomized controlled trial. Am J Clin Nutr. 2025;122(1):122-136. doi:10.1016/j.ajcnut.2025.04.019
10. Nieman DC, et al. Effects of Whey and Pea Protein Supplementation on Post-Eccentric Exercise Muscle Damage: A Randomized Trial. Nutrients. 2020;12(8). doi:10.3390/nu12082382
11. Spoelder M, et al. Supplementation with Whey Protein, but Not Pea Protein, Reduces Muscle Damage Following Long-Distance Walking in Older Adults. Nutrients. 2023;15(2). doi:10.3390/nu15020342
12. Klug L, et al. Delayed Plasma Amino Acid Response following Ingestion of Extruded Pea Protein Compared with Nonextruded Pea Proteins in Healthy Adults: A Randomized Crossover Trial. J Nutr. 2026;156(9):101746. doi:10.1016/j.tjnut.2026.101746
13. Rogers LM, et al. Postprandial plasma aminoacidemia and indices of appetite regulation following pea-rice blend, pea isolate and whey protein ingestion in healthy young adults. Br J Nutr. 2024;132(6):691-700. doi:10.1017/S0007114524001958
14. Kozior M, et al. An Investigation of the Protein Quality and Temporal Pattern of Peripheral Blood Aminoacidemia following Ingestion of 0.33 g·kg-1 Body Mass Protein Isolates of Whey, Pea, and Fava Bean in Healthy, Young Adult Men. Nutrients. 2023;15(19). doi:10.3390/nu15194211
15. Guillin FM, et al. Real ileal amino acid digestibility of pea protein compared to casein in healthy humans: a randomized trial. Am J Clin Nutr. 2022;115(2):353-363. doi:10.1093/ajcn/nqab354
16. Hawley AL, et al. The Short-Term Effect of Whey Compared with Pea Protein on Appetite, Food Intake, and Energy Expenditure in Young and Older Men. Curr Dev Nutr. 2020;4(2):nzaa009. doi:10.1093/cdn/nzaa009
17. Hildebrand HV, et al. Adult and Pediatric Food Allergy to Chickpea, Pea, Lentil, and Lupine: A Scoping Review. J Allergy Clin Immunol Pract. 2021;9(1):290-301.e2. doi:10.1016/j.jaip.2020.10.046
18. Abi-Melhem R, et al. Is pea our hidden allergen? An American pediatric case series. J Allergy Clin Immunol Glob. 2023;2(2):100090. doi:10.1016/j.jacig.2023.100090
19. U.S. Food and Drug Administration. Food Allergies. https://www.fda.gov/food/nutrition-food-labeling-and-critical-foods/food-allergies
20. Bethencourt-Barbuzano E, et al. Plant-based protein supplements as emerging sources of metal exposure: A risk assessment study. J Trace Elem Med Biol. 2025;91:127703. doi:10.1016/j.jtemb.2025.127703
21. National Institute of Diabetes and Digestive and Kidney Diseases. Definition & Facts for Lactose Intolerance. https://www.niddk.nih.gov/health-information/digestive-diseases/lactose-intolerance/definition-facts
22. Vasconcelos QDJS, et al. Whey protein supplementation and its potentially adverse effects on health: a systematic review. Appl Physiol Nutr Metab. 2021;46(1):27-33. doi:10.1139/apnm-2020-0370
23. Sompochpruetikul K, et al. Whey protein and male acne: A double-blind, randomized controlled trial. J Dermatol. 2024;51(7):1022-1025. doi:10.1111/1346-8138.17109
24. Bethencourt-Barbuzano E, et al. Whey Protein Dietary Supplements: Metal Exposure Assessment and Risk Characterization. Nutrients. 2023;15(16). doi:10.3390/nu15163543