The 5 Best Supplements for Muscle Growth, According to Strength Coaches may earn compensation through affiliate links in this story. Learn more about our affiliate and product review process here.
Whey protein, casein protein and creatine are among the best supplements to help you build muscle and improve performance.
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If you've ever shopped for muscle-building supplements, you know there are endless options out there — which can make it difficult to figure out how to choose the very best supplements for muscle growth.


Here's the deal: If you want to build muscle, you have to give your body all of the right building blocks — nutrients, vitamins, water, oxygen flowing to your muscles and amino acids. Amino acids are what make up protein, which then builds muscle tissue. Without them, you can work out all you want, but your body can't make any muscle. It's kind of like a construction site without the raw materials.

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The best way to get those materials? "Consuming whole foods at mealtime," Ashley Kavanaugh, PhD, CSCS, an exercise physiologist and sports performance coach at Renaissance Periodization, tells

If you can't get all the muscle-building nutrients you need from your typical meals and snacks in one day, supplements can help you build more muscle. But not every powder or pill on the market actually works the way it says it does.

In this article, we'll discuss some of the best supplements for building muscle — and a few other types of supplements that can increase performance so you can push harder and ultimately increase those gains.


How We Chose

We spoke with sports scientists, strength coaches and bodybuilders about the muscle-building supplements they trust and use with their athletes and clients. We also dug into the scientific research to see what it has to say about the best supplements for building muscle.

Our picks also take into account the following criteria. You can learn more about how we cover products here.


  • Third-party certification
  • Reputation
  • Purity
  • Purpose

1. Best for Building: Whey Protein

When you're talking about building blocks for muscle, it all starts with protein, the raw material your body needs to build bulk, per the National Institute of Health (NIH).

When it's digested, protein in food is broken down into amino acids. Your body then uses these amino acids to assist a ton of bodily functions, including repairing and building muscle tissue, according to the NIH. If you can't get enough protein from your diet, or are looking to gain muscle or weight, protein powder can be an easy supplementary solution, according to the Cleveland Clinic.



Whey protein, one of the two proteins found in milk, is considered a go-to protein for muscle building because it's digested and absorbed into your tissues quickly, according to a February 2018 study in the ‌Journal of the International Society of Sports Nutrition‌. This means it's available sooner to be turned into muscle.

Another pro of whey protein: It's a complete protein, meaning it contains all of the essential amino acids for building muscle, according to a classic September 2004 article in the ‌Journal of Sports Science and Medicine‌. If you've heard about branch chain amino acids, or BCAAs, you can save your money if you're supplementing with whey. Whey protein already contains all the BCAAs you need.


How to use it:‌ Because it spikes your protein synthesis so quickly and then is metabolized fast, whey protein is often recommended right after a workout.

Shop These Whey Proteins

1. Optimum Nutrition Gold Standard 100% Whey

2. Biosteel Whey Protein Isolate


2. Best for Saving Muscle: Casein Protein

There are two types of milk protein: whey and casein. Casein protein makes up 80 percent of the protein in milk, and it's also what makes milk white, per the 2016 book ‌Encyclopedia of Food and Health‌.

Here's the part muscle-builders should care about: If whey is the best protein for muscle ‌building‌, casein protein is the best for ‌saving‌ muscle. Like whey, it's derived from milk and is a complete protein, per the September 2004 ‌Journal of Sports Science and Medicine‌ research.


But unlike whey, it doesn't spike your amino acids as quickly or as high. Instead, it's digested slowly, according to a May 2017 study in the International Journal of Exercise Scienc‌e. This helps to slow the rate of protein breakdown — saving your existing muscles from being used for fuel.


In a small January 2011 Endocrinology and Metabolism study, scientists found both whey and casein stimulated a similar amount of muscle protein growth over a six-hour period. The casein just took a lot longer to kick in. The study also suggests that a 50-50 combination of whey and casein may be ideal for post-workout supplementation.

Research is limited, but in a small, older February 2001 study in ‌Endocrinology and Metabolism‌, scientists looked at how casein and whey protein affect muscle protein synthesis and breakdown, and found that while whey was better at building, casein significantly reduced breakdown.

How to use it:‌ That extended release makes a scoop of casein ideal for use before fasting, as a late-night snack to keep protein levels up while you sleep or before a long day when you want to stay full.

Shop These Casein Proteins

1. Biosteel Recovery Protein

2. Optimum Nutrition Gold Standard 100% Casein

3. Best for Muscle Fuel: Creatine

Creatine monohydrate is a chemical compound produced in your liver, kidneys and pancreas that plays an important role in making your muscles work.

Creatine monohydrate binds with a phosphate molecule to restore adenosine triphosphate, or ATP, to your muscles, as explained in a March 2021 Nutrients study. ATP is your muscles' energy source for explosive, short-duration work. When it's restored, you can do more reps of high-intensity exercise — so you can put your muscles under more stress, triggering more muscle growth.

"It's not just that it lets you do another rep, though," says Alex Viada, CSCS, founder of Complete Human Performance. "ATP concentration in a cell is responsible for a lot of [muscle-building] processes, including aiding in muscle repair."


It can also help our brains work better.

"So even for athletes who don't have a [muscle-building goal] directly, creatine is still very good for doing things like improving motor learning," Viada says.

Of course, that improved motor learning can also mean doing exercises ‌better‌, which is always a helpful thing when you're trying to build muscle.

How to use it:‌ The research is mixed, but there seem to be benefits no matter when you take it: pre-workout, post-workout or whenever is convenient for you during the day.

Shop These Creatines

1. CytoSport Muscle Milk Pro Series Creatine Powder

2. Gnarly Nutrition Creatine

4. Best for Fighting Cortisol: Ashwagandha Root

Growing your muscles is about building muscle, but also about saving the muscles you have. And cortisol, a hormone that's released in response to stress, can attack your current supply of bulk.

"We all now constantly have these insane schedule changes and constant physical and mental stressors acting on us the last few years," says Brandon Lirio, CPT, director of BattleGround Fitness and a professional bodybuilder. More stress can mean more cortisol. "Cortisol is like a muscle-eating plague, and can affect not just your sleep and happiness, but also your recovery and how much muscle you build."

Ashwagandha root is an herb that has been used in traditional Eastern medicine for centuries. Modern studies have backed up its benefits: A small December 2019 Cureus study found people who took 250 milligrams of ashwagandha root extract per day (125 milligrams twice a day) had lower levels of cortisol and better quality sleep.


Sleep matters for muscle building, too. Sleep deprivation decreases testosterone levels, increases cortisol levels and reduces muscle protein synthesis, according to a small January 2021 study in Physiological Reports.

How to use it:‌ In the 2019 study, participants took 125 milligrams twice per day. Try it in the morning and evening. Ashwagandha should not make you drowsy, like a sleep aid, so you can take it before a workout, and you don't have to take it right before bed.

Shop These Ashwagandha Supplements

1. Agobi Ashwagandha

2. Transparent Labs KSM-66 Ashwagandha

5. Best Vitamin: Vitamin D

While you probably know the importance of D for your bone health, it's also crucial for maintaining and building muscle.

In one December 2010 Hormone and Metabolic Research study, a small group of participants who identified as men and took a vitamin D supplement for a year had significantly more testosterone in their systems than those who didn't take the supplement.

What we do know: It's common to be deficient, and risk factors for vitamin D deficiency include race, obesity and even education level, according to a June 2018 research review in ‌Cureus‌.

How to use it:‌ The National Institute of Health recommends adults get 600 international units (IU) or 15 micrograms (mcg) daily, though other organizations, like the Endocrine Society, recommend more (up to 1,000 IU daily). Talk to your doctor about a blood test to help you determine if you're deficient and need a higher-dose supplement to boost your levels.

Shop These Vitamin D Supplements

1. Designs for Health Vitamin D Supreme

2. Nature Made Vitamin D3 Softgels

5 Things to Consider When Buying Muscle-Building Supplements

1. Third-Party Certification

Unlike food, the nutritional claims of dietary supplements aren't regulated by the Food and Drug Administration — the law does not require the supplement company to prove that what it prints on the label is actually true.

When shopping for supplements, look for products that have been tested independently by one of these three third-party laboratories:, NSF International and the U.S. Pharmacopeial Convention (USP). These organizations test supplements and ingredients for quality, purity, potency and more.

2. Brand Reputation

After looking for third-party certifications, you may still find yourself with a large selection of options. Look at the reputation of the brand you're buying. Search to see if the brand has had supplements recalled in the past, which is a red flag.

Established supplement brands have more of a reputation to protect, so you may feel more confident their product includes what's actually on the label and will provide results.

3. Other Ingredients

Sometimes a "protein powder" has much more than protein. It may have some creatine already mixed in, tart cherry or beet root extract for recovery, caffeine or some other supplement.

While the labels of these products are not regulated by the FDA, the companies making them aren't necessarily "lying" on the labels — sometimes they include these ingredients to turn a supplement into a muscle-building mix. Read the ingredients list so you can see what's really inside, and decide if you want those additional components.

Another addition you might not expect: sugar. Some cheaper supplements include lots of sweetener, which you may not really want or need.

4. Compatibility With Other Meds

Always talk to your doctor before adding any new supplements or herbs to your regimen, but especially if you take prescription medication.

Supplements can interact with drugs, reducing or canceling out their effects. For example, ashwagandha root can interfere with diabetes and blood pressure medications, according to the National Library of Medicine.

It's just not worth jeopardizing your health to try and get a small edge in muscle building. Always talk to your doctor to rule out potential negative drug interactions.

5. Dietary Restrictions

If you have dietary restrictions, it's even more important to read the label: Make sure the supplement you're buying doesn't contain ingredients you can't digest, are allergic to or don't want to take in.

For example, several of the supplements listed above come from milk. If you can't stomach lactose, you may find that you're okay consuming whey isolate or casein isolate in place of whey and casein protein supplements, per the American Dairy Products Institute.

Isolates essentially contain just the protein — most of the fat and lactose is removed. They tend to be a little more expensive, but are usually more digestible for people with lactose intolerance. Note: They still aren't safe for dairy allergies.

If that isn't working for you — or if you're vegan — plant-based proteins are available. Pea protein, as found in this Ladder Sport Plant Protein supplement, has become a popular option, though its effectiveness has not been as extensively studied.

More Protein Powders We Love




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