Whey Protein vs. Pea Protein

In response to the recent post on whey vs. collagen, a number of readers wrote in asking about pea protein. Today, I’m going to compare the two.

Before I begin, let’s get this out of the way: I’m biased toward whey protein. I sell the stuff. But the reason I sell whey protein is because I really like it, not the other way around. All my products are things that solved a problem I was having, an itch I needed to scratch. I made Primal Kitchen Mayo with avocado oil because I couldn’t find one without industrial seed oils and I didn’t want to make it fresh every time I wanted tuna salad. I put together Adaptogenic Calm (formerly Primal Calm) to help me and my buddies recover from heavy training. And so on. I made Primal Fuel out of whey protein isolate because it is the best gram-for-gram protein powder around. But pea protein is having its day in the sun now, and readers want the facts.

Common Arguments For Pea Protein

Is pea protein just as good as whey at building muscle?

Well, let’s take a look at the literature.

First of all, pea protein contains all 9 essential amino acids. That’s great.

Pea protein contains fewer branch chain amino acids—those amino acids that contribute most to muscle protein synthesis, but it does have them.

Pea protein is about 9% leucine, a very important amino acid for muscle building. Whey is 10-11% leucine, so pea comes pretty close.

In one study, resistance trained men and women in their 20s-40s were split into two groups. One group used pea protein. The other used whey protein. Both groups trained in the same manner (Crossfit-esque). At the end of 8 weeks they measured changes in muscle thickness, force production, and WOD (workout of the day) performance. Neither group had an advantage. Both groups gained about the same amount of muscle, performance, and force production.

In another study of resistance-training adults (men, aged 18-35), pea protein and whey protein resulted in similar bicep muscle gains.

That all looks pretty good for pea (and whey), but these were relatively young adults. As people age, the quality of the protein becomes ever more paramount. A young man or woman is hormonally primed for hypertrophy. Nature is working with them, not against them. If anything, they can actually get away with eating less protein than an older person of the same weight and still gain and maintain muscle because their ability to utilize dietary protein is optimized. Older people need more protein to do the same job because their ability to utilize dietary protein has degraded.

Not only do older people need high quantities of protein, they need high quality protein—bioavailable protein full of amino acids that promote muscle protein synthesis. Whey is simply higher quality on a biological level than pea protein. That difference may not show up as much in the younger person lifting and drinking protein shakes to increase their calories for mass gain, but it certainly shows up in the older person lifting and drinking protein shakes and trying to hold on to their lean mass.

Okay. You’re younger. You’re eating plenty of calories. You’re trying to gain weight. Your muscle protein synthesis capacities are optimal. You should, in theory, be fine with pea protein. Right? Sure, but why?

Pea protein is usually more expensive. It’s still technically lower quality than whey. The best justification for using pea protein to gain/maintain muscle is either you’ve got an uncle who works at a pea protein processing plant and can get you a great deal, or you’re vegan. That’s it.

All that said, pea protein looks to be the best plant-based protein around for performance in the gym. No arguments there.

What about high blood pressure? I’ve seen claims that pea protein can lower it.

Perhaps. In hypertensive rodents (probably working high stress jobs, enduring long commutes, and generally deep into the rat race), pea protein causes drastic reductions in high blood pressure, while the reductions are much more modest in humans taking pea protein daily for three weeks.

Whey does it too. In humans, a single dose of whey protein after a meal reduces postprandial blood pressure and improves arterial stiffness for up to 5 hours. It may just be the protein. Extra protein in general is great at lowering blood pressure, especially if you remove carbohydrates.

The (Relatively) Unique Strengths Of Whey Protein

The thing about protein powder is this—although whey gets most of its accolades on account of its effect on hypertrophy—gains, larger muscles, better performance, etc.—that’s not everything it can do. It also has some very unique health effects that other protein powders, most especially plant proteins like pea, do not possess.

Whey is anti-allergenic.

On the one hand, whey intolerance is the dairy protein intolerance with the lowest incidence. People are far more likely to be intolerant of or allergic to casein. But whey isn’t just less likely to be allergenic. It’s downright anti-allergenic. Whey-based formulas have shown efficacy in the prevention of allergic diseases like asthma and eczema in susceptible children and infants.

There’s no evidence that pea protein powder can do this.

Whey is anti-stress.

In “high-stress” subjects, a whey protein shake improved cognitive function and performance by increasing serotonin levels. The same shake had no effect on “low-stress” subjects. And dietary whey also lowers oxidative brain stress, at least in mice.

Pea protein may do this, but I haven’t seen the research.

Whey boosts antioxidant capacity.

Whey protein is one of the best foods we know that increase levels of glutathione—the body’s master antioxidant. We use glutathione to detoxify the liver, to metabolize alcohol and other toxic substances, to control allergic reactions, to recycle and restore to active status vitamins and antioxidants, to quell free radicals, and to perform many other vital processes.

There is simply no evidence that pea protein has the same effect. It doesn’t have enough cysteine.

Whey transforms when you digest it.

Once the whey protein hits your GI tract, many different bioactive peptides with their own unique effects are formed. In a recent review (PDF), a team of Polish researchers explored the effects of at least nine of these whey-derived peptides. Some improve blood lipids, lower blood pressure, or act as opioid receptor agonists (if you’ve ever seen a milk-drunk baby bliss out after nursing, his opioid receptors are likely being severely agonized by bioactive peptides). Others induce satiety and improve metabolic health biomarkers.

I’m sure other proteins change when digested, but their effects haven’t been studied as closely as whey.

Bioactive Components In Whey (But Not Pea Protein)

There are also a number of bioactive components in whey protein that are not in pea protein:




  • Improves bone healing and prevents bone loss.
  • Chelates excessive iron, preventing it from fueling infections (many bacteria require iron), increasing inflammation, or becoming carcinogenic.
  • Has anti-bacterial effects against food pathogens like E. coli and Listeria.

Immuno-globulins (A, M, G)

Could pea protein have similar aspects that have yet to be quantified and studied? Perhaps. But I doubt it.

After all, whey was designed by evolutionary processes to be food for other entities. It’s meant to be consumed—that’s its express purpose, and it’s why it has so many interesting bioactive components that support health.  Pea protein was not, and likely does not.

Again, if you’re vegan and looking to gain muscle, pea protein is a great choice. But if you’re not, and you’re interested in other aspects of health, whey protein is the much better option.

Thanks for reading, everyone. Take care!


Banaszek A, Townsend JR, Bender D, Vantrease WC, Marshall AC, Johnson KD. 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)

Babault N, Païzis C, Deley G, 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.

Teunissen-beekman KF, Dopheide J, Geleijnse JM, et al. Protein supplementation lowers blood pressure in overweight adults: effect of dietary proteins on blood pressure (PROPRES), a randomized trial. Am J Clin Nutr. 2012;95(4):966-71.

Bumrungpert A, Pavadhgul P, Nunthanawanich P, Sirikanchanarod A, Adulbhan A. Whey Protein Supplementation Improves Nutritional Status, Glutathione Levels, and Immune Function in Cancer Patients: A Randomized, Double-Blind Controlled Trial. J Med Food. 2018;21(6):612-616.

Chandra RK. Food hypersensitivity and allergic diseases. Eur J Clin Nutr. 2002;56 Suppl 3:S54-6.

Markus CR, Olivier B, De haan EH. Whey protein rich in alpha-lactalbumin increases the ratio of plasma tryptophan to the sum of the other large neutral amino acids and improves cognitive performance in stress-vulnerable subjects. Am J Clin Nutr. 2002;75(6):1051-6.

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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46 thoughts on “Whey Protein vs. Pea Protein”

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  1. As an aside, when I (briefly) tried pea protein (310) I had the WORST gas of my life. Like old-dog-farts gas. My family BEGGED me to stop drinking the stuff. Also, no matter how I prepared it, it was grainy. Now it could be that I am just sensitive to peas (though I never have been before…) but it is not something I ever want to repeat. Thanks, Mark, for all you do. As a 66 year old going through a major lifestyle change, I’ve learned so much from you that, even if I lived to be 1000, I could never repay you! So go you!!!!

  2. Whey protein in smoothies made me feel great, but after a year of 3 times per week use, I started to get joint swelling in my hands and feet. My blood work showed elevated thyroid antibodies, which I was told can cause those symptoms. After some research, I found that Dr. Izabella Wentz suspects that whey protein can elevate thyroid antibodies is some individuals, and exacerbate Hashimoto’s. I’m hoping that the whey protein isn’t the culprit, as I feel a definite health boost when I use it.

    1. That’s very interesting. But if it was me, I’d choose the quality of life over some blood test. Unless they can prove it’s the whey. Which it doesn’t seem that they’re sure.

  3. Very interesting article!! As a biomed nerd interested in nutrition science, your articles that break down the details like this are fascinating and helpful. My hubby and I always keep a stock of plain collagen peptides around, and usually rotate between whey and plant based flavored protein powder (whichever is on sale that day lol). I think trying different types of proteins is important. You can see what your body responds best to, as everyone is built a bit different, and that way you don’t get too much of one thing!

  4. Have you made any comparison between Quinoa (or Quinua) and Whey ???

  5. Wow! I’ve always stayed away from whey because of the dairy association and I don’t even have a known allergy or intolerance. I’m just brain-wired to avoid dairy unless I know I’m getting the freshest, cleanest, least process product available. Can you comment on whey vs. egg white protein? I know it doesn’t warrant its own post by the fact I’m having a harder and harder time finding it to buy. ?

  6. Isnt it worth noting whether the whey is from grass fed cows? I feel this is a pretty important distinction to get most of the benefits

    1. I might be mistaken, but I think the protein from conventional feed cows and the protein from grass fed cows is actually pretty similar. It’s the fat profile that is so different. I totally agree with you from an environmental perspective, but I think, in terms of protein, they are pretty similar.

      1. yes the nutrients are in the fat. so a big difference between the 2

  7. So if you have a casein sensitivity, it is safe to use Primal Fuel? The allergen list on the container lists milk.

    1. It’s not safe if your allergy is mediated by IgE. If it’s just a sensitivity and not IgE, then it’s dependent on your personal tolerance level. You can get an IgE milk allergy test for less than $50 at a direct to consumer lab in the US. Here’s mine (it was a package that included all 8 major allergens) https://www.nixgluten.com/2018/03/officially-not-allergic-to-big-8.html

      That test didn’t test me to find out if I have a sensitivity, that’s a different test and kind of controversial. Those are done by Cyrex, or diagnosed by allergists based on keeping a food log.

      Additionally, I’m Celiac, but I’m not allergic to wheat. My reaction is totally different than an IgE allergy would be.

      If all this sounds complex, this is why people end these kinds of comments with “Talk to your doctor” 🙂

  8. I have alpha-gal allergy and have to refrain from all mammal products, meat and dairy both. Does whey protein contain alpha galactose?

  9. What do you think about soy protein? I have used soy powders for the estrogen ice effect during menopause, but now that I am older I wonder if I should give whey powder a try. Thanks!

  10. How does whey protein compare to grrass-fed beef protein (BeefISO), ie Equip’s Prime Protein

  11. Great Read but curious about bone broth protein & collagen protein powder??

  12. Really timely analysis Mark. Up in Canada, pea processing plants are opening all over with huge media coverage on perceived benefits and reducing reliance on red meat, etc. The fast food giants like A&W pushing veggie and plant protein burgers. Similar to trend in Big Tobacco pushing Vape and now doing damage control as the health risks coming out.

    Keep up the great work you do!

  13. Gee … can you get any of these benefits by eating meat? Asking for a friend. 😉

  14. Whey protein makes me break out, which I’ve read is rather common. Bit of a bummer cause it tastes much better than pea protein.

  15. I am highly sensitive to whey protein. Immediately get tightness in my throat after drinking it. Doesn’t seem like this is possible from the info you present here, but it is true. Wish it was anti-allergenic for me!

    1. I can’t drink whey protein either. I’ve tried several different brands and types, always with the same result. About 15 minutes after drinking it I get a very upset stomach that takes a couple of hours to go away.

      I gave up on protein products and just try to get sufficient protein through the food I eat.

  16. Another reason to choose pea protein over whey is if you have a confirmed sensitivity to casein. I’m glad to see the comparisons here though. I cannot ingest whey and choose pea protein as my protein source in smoothies etc. I also use collagen. Many people with autoimmune issues have problems with whey. I’m wondering if grass fed beef protein would be superior to pea protein for me.

    1. Whey might be awesome, just not for them with allergies or sensitivies or those with autoimmune diseases. That is a whole bunch of people, afterwards.

      I can´t neither consume whey or casein. Pea works great for me and I combine with collagen and beef protein.

  17. You start with evidence, when showing how they are pretty much equal, but then you immediately stop citing evidence when you (out of no where) state that whey is superior as you age. You pick up again with evidence-supported statements when you start talking about whey, alone, not compared to pea. So you aren’t really answering the question in the title. The quality of your writing has gone down hill.

    1. Noticed the same. Should actually have stopped reading at “I’m biased toward whey protein. I sell the stuff.”

      Science yes, when it fits my narrative.

  18. I have Hashimoto´s hypothyroidism and cow casein and whey are a huge problem for me. When i consume them, my antibodies are higher and i can feel the inflammation in my body (mostly my joints and headaches), also the bloating.

    I can manage with a little sheep or goat cheese and maybe if goat or sheep whay was available, it could be an option.

    But for now, pea protein is great. I also use beef protein and collagen with good results. In the past i have used hemp (the taste has to be hidden with some avocados) but pea seems to work better.

    However some functional practicioners mean that pea is a legume and that us with autoimmune problems, should avoid it. At the same time, they reccomend coconut everything and many report problems with it…

  19. Really appreciated this post! I have an autoimmune disease and am sensitive to dairy so this was really great to read. Would love to buy your brand (I buy all my other supplements through you) but whey is problematic for me as dairy is a major trigger food sadly.

    On the topic of reader requested posts- may I politely request an updated write up on the carnivore diet? All the new iterations of it and what you think would make it work best? Also why it works? A breakdown of some key foods included and their vitamin and mineral content would be amazing- I get worried you can’t get all you need! I’m interested to try but would love your insights Mark!

  20. In an earlier post, didn’t you say that the problem with grain-free dog food isn’t the fact there’s no grain in there, but rather the fact that they use pea protein. It was speculated that the pea protein might be causing the rise in the heart issues in dogs fed these foods.

    But pea protein is ok for humans?

    Did I miss something important?

    1. Plenty of thiings safe for human consumption but not dogs. Take chocolare and coffee, for example.

      That said, the dog thiing has certainly made me wary of the idea of pea protein as well.

  21. Hi Mark, When you say whey protein is anti-allergenic, have you found that people who are very allergic to dairy products like milk, cheese and butter are able to tolerate it well? Dairy tends to make me wheeze pretty badly. Any links I could read up on? Thank you so much for all that you do!

  22. I just want to add that allergy to casein makes it impossible to take whey protein supplements. If the allergy is IgE mediated, then the person either has to stay away entirely or have desensitization therapy before whey is tolerated. If it’s not IgE, but a food sensitivity, then whey might be ok. I went through a period where I was sensitive to casein and couldn’t even use whey protein. I missed it so much. I’m OK now, but it was a real chore avoiding casein. Whey is back on my ok list.

    The thing about protein powder though, is that it’s essentially a processed food. If it was beef protein powder, everyone would say, “Just eat a steak.” Yet hardly anyone says, “Just curdle milk and drink the whey.”

    One of the big differences between plant food and milk is that milk is designed for a baby animal to eat it. Plant foods are designed to discourage you from eating them. Bitterness, etc. While I’d like to see a lot more research on which plants are helpful to humans and which aren’t (especially herbals that are medicinal), I’m guessing that if it’s food value we’re looking for, milk will outclass any plant.

  23. I choose pea protein to avoid the massive insulin spike caused by whey. I’m diabetic. Subscribing to Jason Fungs theory that high insulin causes insulin resistance my focus is on reducing insulin. I was surprised that you offered no information on this very important difference

  24. If I eat peas I get severe internal bleeding in my gut, often not revealing itself for days after consumption. It took me years to figure this out, and I can’t find any info online about any mention of a similar reaction.

  25. I’m confused. I thought peas were legumes, and therefore not included in Primal or Paleo framework.

  26. The only protein powder I use on a regular basis is collagen peptides, which I mostly take for the benefits I have seen in my skin. And I’ve done fine with whey the few times I’ve used it.

    I tried pea protein for a few days several years ago and felt very bloated and uncomforable, to the point that I’ve never even wanted to try it again. It also appeared to trigger my cystic acne, which was no fun.

    At the end of the day, I really prefer to get my protein from whole foods like pastured eggs, grass fed beef and wild caught fish. But when I want to supplement, I’m sticking with collagen and whey!

  27. I do not understand all the attention being given to whey or any other powdered protein. They are not natural food. It is pretty obvious to me that these are NOT foods that my ancestors would have eaten. The only reason that I can see for consuming whey rather than whole milk is a casein sensitivity. But even so, there are plenty of other whole proteins that you can eat.
    I think that there is huge potential for companies to use low-quality materials to make any processed food product. And I don’t think our bodies are optimized for eating these processed food products, either.
    Eat real food!

  28. I would also like to point out that you can get pea protein from eating peas. No need to go with powder. Getting whey is not that easy so there using a powder may be useful, though many also contain sweeteners and soy products.

  29. What about hormones and women when comparing whey to pea protein. I felt that whey I gained weight and not the good muscle kind but the midsection. Where as pea I was able to maintain weight and muscle even when lowered exercise levels.

  30. I am trying to regain muscle mass at age 60, and I am missing one kidney.I recall seeing a post somewhere about pea protein being easier on kidneys than other forms. Have you seen any research regarding that?

    1. Hi Robert – also look into supplementing with magnesium – and get vitamin D checked -make sure it is at optimal level (Optimal: 50-80 ng/mL or 125 to 200 nmol/L) and that you also take vitamin K.
      At same age my muscle strength and endurance has improved with this since adding magnesium.

  31. Sorry Mark but whey protein can and does cause allergic reactions in people and is contraindicated for those with auto-immune or thyroid issues. So there are definitely good reasons for people to use pea protein powder. A little more research would have benefitted your followers greatly. But you did acknowledge your bias and that made me do more research and I am glad I did!

  32. Fantastic article! You nailed it so to speak. Yes, when I was younger I liked going on little protein and did fine as a vegetarian. Recently turning around completely but not to meat. For me, adding an egg was a time when I noticed and understood my body rejoicing! That was yesterday. I’ve been using pea since I started adding protein. Anyway… checked out your product; don’t know if it’s on amazon. I’ve decided on two brands, BN Grass Fed, is the first I’ll be trialing. Actually I can’t wait until it arrives… that’s how ‘desperate I have gotten since seeing clearly what’s in back of all my digestive issues that I never had in the past and it all has to do with getting older and have none of the things my body so much needs, as a vegetarian! I won’t be switching to meat but certainly am cutting out roughage from grains entirely… making milk of what I have until I use it up… squeezing out as much fiber as I can, and adding eggs and whey to the diet. What I am approaching is a liquid diet and actually… I can’t wait! KEFIR, home cultured kefir is the most beautiful spiritual and physical experience for me. I don’t know if it’s keto. Re: whey, BN’s price is good. I’ve tended toward the concentrate as I think the very things you mention as special to whey and not in pea, are higher in concentrate than isolate? But you’re selling isolate I think. I’ll keep reading. Anyway, thanks for the article.

  33. Grass fed whey has all those components that pea protein does not have but regular whey if it has them has less of all of them. That’s what I meant to say in another comment – it isn’t an isolate vs concentrate issue as I wrongly wrote but it is a grass fed vs regular whey issue.