Key Takeaways

  1. How much protein you eat every day is far more important than where you get that protein.
  2. Whey and casein protein are the best protein powders for muscle growth overall, although a combination of pea and rice protein powder is a comparable vegan alternative.
  3. Soy, hemp, collagen, and gelatin protein are the worst mass-marketed protein powders for muscle growth.

When you think of protein powders for building muscle, you probably think of whey protein.

I know that’s the first one I thought of when I started lifting weights.

Over the years, it’s become not just a staple of bodybuilder’s but also a standard by which all other protein powders are measured.

Although whey used to be the only option for a while, now you can find many other kinds of animal and plant protein including casein, beef, egg, pea, hemp, soy, and others.

Poke around online and you’ll also hear various arguments as to why one protein is better than another.

Some say whey is the best because it’s easy to digest and spikes amino acid levels in your blood.

Others say that casein is the best because it digests slower and provides a steady stream of amino acids to your muscles.

And others say that plant proteins like pea, hemp, and soy are just as good as animal-based ones for building muscle, whereas others strongly disagree.

Who’s right?

You’re going to learn the answer to that question, and more, in this article.

By the end, you’ll know . . .

  • How protein helps you build muscle.
  • How whey and casein compare when it comes to muscle growth.
  • Why collagen and gelatin are absolutely awful protein powders for building muscle.
  • How vegan proteins like rice, pea, soy, and hemp protein compare to animal proteins for building muscle.
  • Whether or not hydrolyzed and cold-filtered protein powders are better for muscle growth.
  • And more.

Let’s get started.

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How Does Protein Help Build Muscle?

Before we get into the best protein powders for building muscle, let’s first look at the overarching goal: muscle growth.

More specifically, how eating protein (including protein powder) helps you build muscles.

The first reason protein helps build muscle is because muscle is protein.

In other words, it provides the raw materials necessary for muscles to grow. The concrete for building the foundation of a building, if you will.

You see, our skeletal muscles aren’t just responsible for helping us move. They’re also a storage site for amino acids, which can be poached for other purposes by different organs.

For example, if the liver, skin, or bones require more amino acids for remodeling and repair, they need to get them somewhere, and skeletal muscle is an appealing source of these vital nutrients.

When other organs are hungry for amino acids, they’ll often borrow them from skeletal muscle or the liver and intestines, which can also store limited amounts of amino acids. If this is kept up for a long time then muscle loss will occur . . . unless you provide your organs with another source of amino acids.

That’s where dietary protein comes into play.

Our organs can also use amino acids obtained from the food we eat, of course. Every time we eat a chicken breast, steak, or piece of salmon, our bodies break down the amino acids in these foods and distribute them to various organs in the body.

As a baseline, then, you want to be consuming enough protein to prevent your body from cannibalizing your muscle for amino acids.

That is, you want to eat enough protein to at least maintain your muscle mass.

If you’re like most people, though, you don’t want your muscles to stay the same size.

You want them to grow, and grow fast.

Turns out that protein can help in this department, too.

Like exercise, some amino acids found in protein also signal muscles to grow.

The primary protein with this property is known as leucine.

Leucine is found in abundance in many animal (and some plant) proteins, and it not only serves as a structural component of muscle but also directly stimulates muscle growth.

We don’t need to get into the exact mechanisms at play here, but the long story short is that leucine stimulates a protein in the body called mTOR, which when activated, tells muscle cells to collect and store amino acids.

As we’ll get into in a moment, the best proteins for muscle growth are also generally going to contain a fair amount of leucine.

By combining a signal telling muscle to grow and also being the component by which muscle does grow, dietary protein is stored in ever increasing amounts in our skeletal muscle which leads to them getting bigger.

So, how much protein should you eat every day?

In general, you want to aim for about 0.8 to 1.2 grams of protein per pound of body weight per day, which is generally around 40% of daily calories for most people.

If you want to learn where these numbers come from and more about how to decide how much protein you should eat, read this article:

How Much Protein Do I Need? The Definitive (and Science-Based) Answer

Summary: Protein supports muscle growth by providing amino acids for building muscle protein and by directly stimulating muscle growth due to the amino acid leucine.

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What Are the Best Protein Powders for Muscle Growth?

best-and-worst-protein-powder

The best protein powders are going to be those that are tasty, cheap, convenient, and—if all those parameters are hit—something that offers a few benefits beyond the basic requirements.

So, without further ado, here are the top three protein powders for building muscle:

  1. Whey protein
  2. Casein protein
  3. Rice and pea protein mix

Whey Protein

Right, so saying that whey protein is fast absorbed protein is kinda useless and beaten to death at this point.

Yes, whey protein is digested quickly, with a boatload of amino acids entering the bloodstream about an hour after being consumed. After another two to three hours or so, most of the amino acids are already absorbed and being put to use in the body.

You’re probably aware of this benefit, though.

To better understand whey protein’s other benefits, let’s just do a bullet point analysis of what whey protein is and how it differs from other proteins sources:

  • Whey protein is made from the liquid portion of milk—the stuff that doesn’t coagulate when introduced to rennin. The stuff that does bunch up, and later turned into cheese, is casein protein (discussed below).
  • About 0.7% of milk overall is whey. There’s about three times as much casein as whey in milk.
  • Whey protein is quite high in leucine and the other branched chain amino acids (BCAAs) and a respectable source of glutamine—all valued dietary supplements by themselves.
  • It’s possible that the benefits of whey are mostly because whey is just a good source of fast-absorbing essential amino acids and leucine.

Of course, whey isn’t just a bunch of amino acids floating around, they organize themselves into structures known as quaternary proteins. Sometimes these proteins do unique things, other times they just get digested and turn into amino acids.

Regardless, these quaternary proteins can have a number of benefits, which I’ll show you in a moment.

The main quaternary proteins in whey are:

  • β-lactoglobulin (50 to 55% of the whey protein)
  • α-lactalbumin (20 to 25% of the whey protein)
  • Immunoglobulins (10 to 15% of the whey protein)
  • Serum Albumin (5 to 10% of the whey protein)
  • Lactoferrin (1 to 2% of the whey protein)

These numbers are taken from this paper but seem to be derived from an in-print publication. The paper also mentions that sometimes whey, for commercial purposes, is repurposed from other dairy products every now and then so the numbers could vary.

These proteins can be beneficial for reducing blood pressure (ACE inhibition) and may reduce cholesterol as well. Blood pressure reduction has indeed been noted with whey.

Furthermore, due to delayed stomach emptying and reduced appetite seen with whey when compared to other proteins, it could be argued that whey is better for fat loss diets in general.

Plus, whey protein is very well absorbed after being ingested.

This makes it a good protein for pre-workout nutrition, as it quickly passes through the stomach and causes little to no stomach discomfort for most people.

All of these reasons are why whey protein has become the standard by which other proteins are measured, and I’m going to do the same in this article. If other forms of protein are comparable then it’s pretty impressive and, if they fall behind, still fairly okay; second place isn’t anything to scoff at.

That said, if they’re significantly worse than whey protein, they’re probably not worth consuming if your main goal is building muscle.

Summary: Whey is rich in essential amino acids and leucine, it’s quickly digested and absorbed, and it also contains special protein molecules that may have unique health properties.

Casein Protein

Casein protein is the primary protein found in milk, making up about 80% of the total protein.

Casein has gel-forming properties that make it desirable for a number of food products, and it’s also the primary source of protein in cheese products.

If you want to test out these gel-forming properties then put a scoop of casein protein in a bowl and slowly add water or milk when stirring; you get protein pudding.

Due to these gel-forming properties casein is digested and absorbed much slower than whey.

After consuming whey or casein, amino acids begin to appear in the bloodstream about an hour later.

Due to it being rapidly digested, whey protein causes a large spike in blood levels of amino acids after about two hours, after which blood levels of amino acids fall back to baseline.

In contrast, casein is digested much slower than whey, which causes blood levels of amino acids to stay elevated for up to six hours. The tradeoff is that casein doesn’t elevate blood levels of amino acids quite as high as whey protein.

Whey protein seems to be better than casein when it comes to looking at the rate of growth over a short period of time (likely due to the fast absorption of whey) but also in times when the muscle is not at 100%; in aged subjects and following muscle inactivity from a cast.

On the other hand, many experts have suggested that casein protein may be superior to whey because it provides amino acids over a longer period of time.

Ultimately, though, most studies suggest that the difference in muscle growth between whey and casein is negligible. Regardless, if sometimes whey outperforms and at other times casein merely ties then I think we can give whey the unofficial win here.

But whey can’t make pudding.

Summary: Casein protein is high in amino acids and leucine and is digested much slower than whey.

Rice and Pea Protein Mix

Rice and pea protein are sometimes referred to as vegan whey proteins since, despite coming from drastically different sources, they are somewhat comparable in their amino acid profile.

Rice protein alone is pretty high in the essential amino acids and BCAAs, with one study noting that 18% of the total amino acids were BCAAs. Pea protein is similar in how it’s high in BCAAs and glutamine.

Both rice protein and pea protein have, individually, been shown to be effective in promoting muscle gain when used as protein supplements. Both of these studies showed these proteins to be similarly effective to whey protein.

Despite being effective on their own, they’re commonly paired together not only for consistency and taste reasons (with pea having a thicker mouthfeel and rice being relatively smooth) but also because they form a complete protein source.

So ultimately, at least over the short term (8 to 12 weeks) rice and pea protein, and a combination of the two, is comparable to whey protein supplements and a fine vegan substitute for whey. They don’t offer too much more aside from the amino acid, though.

Summary: Rice and pea protein have a similar amino acid profile as whey protein and are also effective for building muscle, but combining the proteins together likely produces better results than taking either of them on their own.

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How Do Other Proteins Stack Up?

best protein powders

Given how we have the two protein powders derived from dairy, and one that is made to somewhat mimic the dairy proteins, what about the other options?

Is mimicking dairy protein all that’s needed or do the other protein powders have their own unique aspects. Are there actually bad proteins when it comes to muscle growth or are they all just different flavors of decent?

Let’s get into that with a look at the obviously contested one; the only protein claimed to give men breasts.

Soy Protein: Not As Bad as Many Think

In the past, when studies on protein were in their infancy, researchers figured they needed to have a control protein of sorts. Something to compare against the other proteins and use as a standard reference.

This was soy protein.

Scientists later found there are compounds known as soy isoflavones that, while sometimes healthy, have minor estrogenic properties. They’re honestly not much of an issue in moderation but it’s never good to have something in your ‘control’ protein screwing with the results.

As such, soy protein comes in both soy isolate and soy concentrate. Generally speaking concentrates lack the isoflavones (they’re treated with an alcohol extraction which takes a large amount of the isoflavones out of the soy) while the isolates contain the isoflavones.

When we look at soy protein that lacks the isoflavones, and is basically just a vegan source of complete protein, it does seem to have similar benefits to whey protein when it comes to muscle growth, at least if timing isn’t considered. Soy protein seems to be less effective for muscle growth when consumed during the workout than whey protein.

A possible long-term benefit to muscle growth associated with whey protein, increased satellite cell recruitment, also has not been seen with soy protein.

All the above also applies to the soy protein containing the isoflavones but they also give benefits to older women who want a daily protein supplement to help mitigate bone deterioration.

Summary: Soy protein is a good source of protein for building muscle. Although it can have slight estrogenic effects in men, this is unlikely to have any negative long-term effects.

Hemp Protein Is as Bland as You’d Expect

So, soy protein is sort of cool because it has unique properties due to being soy.

Whether you get the soy protein with isoflavones or not, at least it occupies an interesting niche.

But what if your protein was, legally, not allowed to be put in the niche?

Hemp protein was probably a really interesting protein source back before regulations prevented THC (the bioactive in marijuana) from being included in it but, nowadays, since it lacks any cannabinoids it doesn’t have any unique properties.

It’s just a source of amino acids.

Even then, the amino acid profile isn’t anything special. It doesn’t have many branched chain amino acids or essential amino acids, making it fairly mediocre in terms of muscle growth.

It basically carries itself on the marketing associated with being one of the few complete protein sources for vegans while also being associated with marijuana.

Summary: Hemp protein has relatively few essential amino acids compared to whey, casein, pea, or rice protein, and doesn’t have any advantages over these proteins, either, making it a poor choice for building muscle.

Collagen and Gelatin Are Basically Trash

It’s pretty clear at this point that, when talking about how good a protein source is for athletics and body composition, that the major factor are the amino acids it provides. The branched chain amino acids and overall essential amino acid content are pretty important.

Casein, soy, rice, fricking peas can all be comparable to whey protein if they just have similar levels of the good stuff as whey protein.

So what happens when you don’t have the good stuff? The result is just, well, a bunch of amino acids and not the ones you even want.

And that is what we see sometimes on the market, a bunch of random scrap amino acids thrown together under buzzwords.

For the most part this refers to gelatin protein or collagen protein (not the type II collagen used in Fortify) but, practically, it’s basically powdered glycine; the cheapest amino acid to produce.

Summary: Collagen and gelatin protein are some of the worst proteins for muscle growth. They have very little of the amino acids that help with muscle growth and no other benefits.

What About the Protein Buzzwords?

best protein powder for weight gain

Choosing between whey, casein, or soy is not the end-all-be-all of choosing a protein. Many times you see other buzzwords associated with these proteins beyond the standard isolate and concentrate.

Casein hydrolysate, cold-filtered whey protein, etc. Do these terms even mean anything or are they just meaningless terms to make the label look prettier?

“Hydrolysate”

Protein hydrolysates, or ‘hydrolyzed’ proteins, first came onto the scene when it comes to baby formulas, oddly enough.

Milk is nutritious but also contains many things that a baby’s gastrointestinal tract cannot properly digest, as well as some allergens. Partial hydrolysis of whey has been investigated for potentially reducing how allergic infant formulas are.

It’s unclear why hydrolysis was introduced into sports supplements but there are two major things that appear to be happening with them when compared to regular proteins; they’re significantly more soluble (to the point of casein losing its gel forming properties when hydrolysed) and the bioactive peptides may be able to act faster.

Whey protein hydrolysate has been shown to have an effect on the intestines in a manner suggesting it may cause laxation (when whole whey failed to have this effect) and could have inherent antioxidant effects that act in the intestinal tract (of rats in this study).

So it seems that acid hydrolysis can do some things to the quaternary proteins and make some unique ones, cool!

For exercise, however?

It does appear to be useful as a protein supplement and direct comparisons to other whey variants have found no major differences for muscle growth, strength, or satellite cell recruitment (which may promote long-term muscle gains).

There was a difference in fat loss favoring hydrolyzed though, no idea as to why but it should be looked into again.

For now, the major factor with hydrolyzed proteins is that they are insanely water soluble to the point where it looks like you’re just drinking colored water. It would be cool if that fat loss result could be replicated.

Also, generally speaking, proteins that are hydrolyzed get a pretty bitter taste associated with them (bad enough specific studies have been conducted to try and cover it up).

It can be covered up with flavoring agents of course but, just be warned, if you have the option to buy unflavored and unsweetened hydrolyzed proteins then don’t. If you did anyways, adding sweet and tart (perhaps sucralose with malic acid) is the way to go.

Summary: Hydrolyzed protein is digested faster and is more water soluble than non-hydrolyzed protein, but it’s also extremely bitter and has no additional muscle-building benefits.

“Cold-Filtered”

Cold filtration is a process by which protein is chilled, during processing, in an attempt to lessen how much of the protein gets denatured.

Denaturing, in this sense, refers to when amino acids actually lose their ‘amine’ group which would make them utterly useless nutritionally. Proteins can take some heat but there’s always going to be a point where they break down beyond repair.

Only problem here is that while the process may have some benefit to specific proteins that are sensitive to heat, whey isn’t really one of them. It’s not like standard whey processing uses enough heat to destroy the whey anyways; that would defeat the purpose.

Furthermore, there appear to be no studies conducted comparing cold-filtered whey protein versus other variants when it comes to any health parameter.

It seems like it’s just a buzzword.

Summary: “Cold-filtered protein doesn’t have any advantages over regular protein—it’s just a marketing term used to sell protein powder.

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The Bottom Line on the Best Protein Powders for Muscle Growth

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Protein supports muscle growth by providing amino acids for building muscle protein and by directly stimulating muscle growth due to the amino acid leucine.

When it comes to protein and muscle building, the most important thing is simply eating enough protein every day.

What kind of protein you eat to reach your daily protein target is far less important than how much you consume.

That said, protein powders offer one of the most convenient ways to hit your daily protein target.

What’s more, some kinds of protein powder also have unique benefits that extend beyond their muscle-building properties.

All things considered, whey and casein protein are the best protein for building muscle.

Some research says whey is slightly better and some says casein is slightly better, but in the end it’s a wash. They’re both exceptionally high in essential amino acids and leucine and are both easily digested and absorbed.

Rice and pea protein have a similar amino acid profile as whey protein and are also effective for building muscle, but combining the proteins together likely produces better results than taking either of them on their own.

Soy and hemp protein are decent vegan protein powders, but they also don’t have any advantages. Soy protein also may have slightly estrogenic effects in men.

Hemp protein has relatively few essential amino acids compared to whey, casein, pea, or rice protein, and doesn’t have any advantages over these proteins, either, making it a poor choice for building muscle.

Hemp protein has relatively few essential amino acids compared to whey, casein, pea, or rice protein, and doesn’t have any advantages over these proteins, either, making it a poor choice for building muscle.

Hydrolyzed proteins are digested faster than non-hydrolyzed proteins, but this doesn’t offer any benefits in terms of muscle building.

“Cold-filtered” whey isn’t any better than non cold-filtered whey. It’s just a buzzword.

So, what’s the final word on the best protein powder for building muscle?

Get a high-quality whey or casein if you aren’t vegan. I suggest you give Whey+ isolate protein powder or Casein+ protein powder a whirl.

If you are vegan, go with pea protein or a pea/rice protein blend, like Thrive.

If you don’t have the funds or the desire to get a supplement then don’t worry too much. Won’t make or break anything in the long run.

What’s your take on protein powders for muscle growth? Have anything else you’d like to share? Let me know in the comments below!

+ Scientific References