Browse any online or brick-and-mortar supplement store, and you’ll find a plethora of supplements for building muscle.

So many, in fact, that it can be difficult to know which supplements work for muscle growth and which are completely bogus.

The truth is that most weightlifting supplements being sold as the “best supplements for muscle growth” will do little to help you reach your health and fitness goals. Actually, that’s being diplomatic—most of them are hot garbage. 

In this article you’ll learn about the only supplements you need to build muscle fast (plus a few well-known muscle building supplements you should definitely avoid).

If you want to know about the best muscle-building supplements money can buy, this is the article for you!

(If you’d prefer to skip all of the scientific mumbo jumbo, though, and you just want to know exactly what supplements to take to reach your fitness goals, no problem! Just take the Legion Supplement Finder Quiz, and in less than a minute, you’ll know exactly what supplements are right for you. Click here to check it out.)

The 7 Best Muscle-Building Supplements

1. Whey Protein Powder

Why it’s important: When it comes to bodybuilding supplements, whey protein powder is most people’s top pick—and for good reason. 

Not only is it rich in the amino acid leucine—an amino acid that plays a vital role in stimulating protein synthesis—it’s rapidly digested and easily absorbed by the body. In other words, it kicks off the muscle-building process, then provides everything the body needs to get the job done quickly and easily. 

What’s more, high-quality whey protein powder tastes good and tends to provide a lot of protein per dollar spent, so it’s convenient and cost-effective.

How to take it: Mix whey protein powder with 8-to-10 ounces of water, milk, or your favorite beverage. If you like to use whey protein powder as part of your pre-workout nutrition, take one 30-gram serving 30-to-60 minutes before working out. For post-workout nutrition, take one 30-gram serving within 60 minutes of finishing your workout if you weigh less than 150 pounds and 2 servings if you weigh more than 180 pounds.

Best source: If you want to enjoy a 100% natural grass-fed whey isolate protein powder made with milk from small, sustainable dairy farms in Ireland, try Whey+.

2. Casein Protein Powder

Why it’s important: Like whey protein powder, casein protein powder is a well-digested and well-absorbed weightlifting supplement that’s tasty, convenient, and rich in essential amino acids. That’s why most scientific research shows they’re more or less comparable when it comes to building muscle.

Unlike whey, which causes a large spike in blood levels of amino acids immediately after you consume it, casein is digested slowly, which means it provides a steady, gradual release of amino acids into the blood for several hours. This is why many people use casein to speed up muscle recovery by consuming it before they go to bed.

How to take it: Mix casein with 8-to-10 ounces of water, milk, or your favorite beverage. For pre-bed nutrition, take one 30-to-40-gram serving 30-to-60 minutes before going to sleep. For pre-workout nutrition, take one 30-to-40-gram serving 30-to-60 minutes before working out. For post-workout nutrition, take one 30-to-40-gram serving within 60 minutes of finishing your workout if you weigh less than 150 pounds and 2 servings if you weigh more than 180 pounds.

Best source: If you want a clean, 100% natural, delicious micellar casein protein powder that’s naturally sweetened and flavored and contains no artificial dyes or other chemical junk, try Casein+. 

3. Plant Protein Powder

Why it’s important: Despite what vegans often preach, veggies aren’t a great source of protein. Animal protein is superior to vegan protein for building muscle because it’s better absorbed by the body and contains much larger amounts of the amino acid leucine, which directly stimulates muscle growth. This is why it can be difficult to hit your daily protein target while following a plant-based diet.

One solution to this problem is to simply eat more total protein, but this can be impractical and unpleasant (you can only get so much protein from peas before your bowels knuckle under). 

A better approach is to supplement with plant protein powder. Generally speaking, the best plant-based protein supplements to build muscle fast are blends of rice and pea protein. This is because they’re easily digested, taste good, and contain high amounts of the essential amino acids leucine, isoleucine, and valine, which make them particularly good for building muscle. 

Thus, it’s not surprising that research shows a mix of pea and rice protein is about as effective as whey protein for building muscle. 

How to take it: Mix plant protein powder with 8-to-10 ounces of water, a non-dairy milk, or your favorite beverage. If you like to use plant protein powder as part of your pre-workout nutrition, take one 40-gram serving 30-to-60 minutes before working out. For post-workout nutrition, take one 40-gram serving within 60 minutes of finishing working out if you weigh less than 150 pounds and 2 servings if you weigh more than 180 pounds.

Best source: If you want a high-protein, all-natural, and nutritionally enhanced plant protein powder that’s also delicious to drink, try Plant+.

4. Creatine

Why it’s important: Creatine is a compound made up of the amino acids L-arginine, glycine, and methionine, and it’s one of the best natural supplements for muscle growth there is. In fact, the best muscle-building supplement after protein.

Research shows supplementation with creatine . . .

  • Boosts muscle and strength gain
  • Improves anaerobic endurance
  • Reduces muscle damage and soreness from exercise
  • Increases the amount of glycogen your muscles can store
  • Helps preserve lean mass and strength while restricting calories

. . . and in case you’re worried that creatine is bad for your kidneys, these claims have been wildly overblown. Creatine supplementation isn’t advised in cases of kidney disease treated by diuretics, but in healthy people, both short- and long-term usage of creatine has no harmful side effects whatsoever.

How to take it: Research shows that supplementing with 3-to-5 grams of creatine per day is optimal for improving strength, power, and muscle growth and recovery.

Taking around 20 grams per day for the first 5-to-7 days may or may not help creatine exert its benefits sooner, but since creatine is relatively cheap, there’s no downside to “loading” it when you first start taking it. 

For years, many people thought you needed to take creatine post-workout to maximize its effects, but more recent research has found this isn’t the case. You can take creatine any time during the day and get the full benefits.

Best source: If you want a 100% natural source of creatine that also includes two other ingredients that will help boost muscle growth and recovery, try Recharge.

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5. Caffeine

Why it’s important: Many of us can’t shake the cobwebs without our morning cup of coffee, but this powerful compound is a lot more than a mere pick-me-up. 

As well as getting you revved up for your workouts, research shows that caffeine boosts metabolism, improves strength, promotes muscle endurance, and enhances anaerobic performance. 

In other words, it helps you get your head in the game, provides you the energy you need to push harder and longer in the gym, and it helps you burn a few extra calories to boot.

How to take it: Some studies have shown performance benefits with dosages as low as 3 milligrams per kilogram of body weight, but 5-to-6 milligrams per kilogram is more common and generally accepted as the “optimal” dose for maximizing caffeine’s benefits while also mitigating unwanted side effects.

To put those numbers in perspective, 6 milligrams per kilogram would be about 300 milligrams for a 120-pound woman (~3 cups of coffee) and 500 milligrams (~5 cups) for a 180-pound man. That’s much more than most people ingest before training, which is usually closer to 100-to-200 milligrams.

If you’re new to caffeine, consume 3 milligrams of caffeine per kilogram of body weight 15-to-30 minutes before your workout to assess tolerance. If you don’t experience any unwanted side effects (jitters, nausea, anxiety, hot flashes, etc.), move up to a higher dosage (closer to 6 milligrams per kilogram of body weight).

Best source: If you want a clean, delicious source of caffeine that also contains five other ingredients that will boost your workout performance, try Pulse.

6. Citrulline Malate (L-Citrulline)

Why it’s important: Citrulline malate is the amino acid L-citrulline bound with malic acid, a natural substance found in many fruits that’s involved in the creation of cellular energy.

L-citrulline turns into another amino acid in the body known as L-arginine. This increases the production of a gas known as nitric oxide that widens blood vessels and improves blood flow, which in turn improves physical performance.

In one study, participants who supplemented with L-citrulline were able to do around 53% more reps on the bench press than participants who took a placebo. What’s more, the group that took L-citrulline experienced 40% less muscle soreness. This jives with results from several other studies, too.

Research also shows that supplementing with L-citrulline improves aerobic performance.

For example, in one study conducted by scientists at Faculté de Médecine de la Timone, daily supplementation with L-citrulline increased cellular energy production (ATP) during exercise by 34%, which allows you to train at higher intensities for longer periods of time.

How to take it: Mix 4-to-10 grams of citrulline malate with 10-to-12 ounces of water and consume it 15-to-30 minutes prior to exercise.

Best source: If you want an all-natural citrulline malate supplement that also contains five other ingredients designed to increase energy, improve mood, sharpen mental focus, increase strength and endurance, and reduce fatigue, try Pulse.

7. Beta-Alanine

Why it’s important: Beta-alanine is a naturally occurring amino acid that regulates the amount of the molecule carnosine that can be stored in your muscles. Carnosine reduces muscle acidity, which increases the amount of work that your muscles can do before they become fatigued.

That’s why research shows that supplementing with beta-alanine reduces exercise-induced fatigue and increases the amount of work you can do in your workouts.

For example, in a study conducted at The College of New Jersey, researchers found that taking beta-alanine allowed participants to do an average of 22% more reps and lift 18% more total weight in each workout than they could when they took a placebo.

What’s more, research also shows beta-alanine improves anaerobic exercise capacity and reduces feelings of fatigue during exercise.

How to take it: Beta-alanine is often included in pre-workout supplements, so it may come as a surprise that you don’t need to take it before a workout to get the benefits.

Beta-alanine is similar to creatine in that it’s effects are cumulative in nature. It takes several weeks for it to increase carnosine levels in your muscles enough to improve your performance.

That’s why studies show that taking small doses throughout the day is as beneficial as taking it immediately before training. In other words, as long as you consume the clinically effective dose of between 2.6 and 6.4 grams every day, it doesn’t matter when you consume beta-alanine.

Best source: If you want a 100% natural beta-alanine supplement that also contains five other ingredients designed to get you fired up, zeroed in, and ready to crush your workouts, try Pulse.

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The 3 Worst Muscle-Building Supplements

Like I mentioned earlier in this article, not all muscle-building supplements are worth taking. Here are three of the most common muscle-building supplements that aren’t worth a plugged nickel.

1. Testosterone Boosters

There are two main reasons testosterone boosters are a waste of money . . .

  1. Research shows that the ingredients found in most popular testosterone boosters—such as Tribulus terrestris, ZMA, and D-aspartic acid—don’t increase your testosterone levels to any meaningful degree. 
  2. Even if testosterone boosters did increase your testosterone, they would never increase it enough to make a significant difference in how much muscle and strength you gain. This isn’t just my opinion, either—it’s a scientific fact.

The bottom line is that small variations in testoereone levels that are within the normal physiological range simply don’t have much of any impact on muscle or strength gain. It’s only when you take substances (steroids) that dramatically boost your blood levels of testosterone that you see muscle growth take off.

Unfortunately, there just aren’t any (natural) quick fixes for increasing testosterone. That said, through consistent healthy living you can move the needle in the right direction.

If you want to learn more about how to increase your testosterone naturally, check out this article:

How to Actually Increase Your Testosterone (and How Not to)

2. Branched-Chain Amino Acids (BCAAs)

Branched-chain amino acids (BCAAs), are a group of three amino acids that research shows are particularly helpful for building muscle:

  • Leucine
  • Isoleucine
  • Valine

There are quite a few studies that can be cited to convince you that BCAAs improve immune function, diminish fatigue, minimize exercise-induced muscle damage, and enhance post-workout muscle growth.

The problem, though, is the bulk of this research doesn’t directly apply to the average healthy, physically active person who follows a sensible workout routine. What’s more, most of this research was conducted on people following a low-protein diet that didn’t provide much leucine, isoleucine, and valine. Thus, if you eat a high-protein diet, you’ll get all the branched-chain amino acids you need to recover and build muscle from food. Supplementing with more is simply a waste of money.

In fact, there’s research that suggests getting your BCAAs from food is more effective than supplementation (and probably more enjoyable, too).

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3. β-Hydroxy β-Methylbutyrate (HMB)

HMB is one of the chemicals that the amino acid leucine breaks down into in the body.

Companies that sell it as a supplement for building muscle often quote a few studies as proof that it should be counted alongside proven weightlifting supplements such as citrulline malate and creatine as one of the best supplements for muscle growth you can buy. 

The problem is . . .

  • Some of these studies were conducted by Steven Nissen, the inventor of HMB and owner of the patent (conflict of interest much?).
  • The results of other studies are so outstanding that they can only be the result of shenanigans or errors on the part of the researchers. For example, one infamous study found that HMB was more anabolic than steroids. If that doesn’t break your BS-o-meter, then nothing will. 

What’s more, if you review the wider body of scientific literature on HMB and muscle building, you quickly realize it’s mostly a dud.

There is one situation where HMB supplementation makes a lot of sense, however: fasted exercise.

This is because HMB is an extremely effective anti-catabolic agent, which means it stops your body breaking down muscle while you train in a fasted state. It also has no effect on insulin levels, which means you remain in a true, fully-fasted state, even when you take HMB before you train.

If you want to learn more about HMB and its uses in fasted training, check out this article:

This Is the Definitive Guide to HMB Supplementation

And again, if you want help deciding which supplements are the best fit for your budget, circumstances, and goals, then take the Legion Supplement Finder Quiz! In less than a minute, it’ll tell you exactly what supplements are right for you. Click here to check it out.

Scientific References +