Illustration showing a man gaining muscle while losing weight.

The Best Supplements for Muscle Gain & Weight Loss

What are the best supplements for people who are trying to lose weight while building muscle, aka, cutting or body recomposition. There are a few supplements that are good for this, and they all fall into one of three categories:

  1. Protein Supplements. Eating enough protein helps us gain or maintain muscle mass while losing weight. A good example is whey protein.
  2. Muscle-Building Supplements. Supplements that increase our rate of muscle growth, improve our hormones, or help us manage our stress can help us shuttle nutrients towards muscle growth, allowing us to burn more fat. A good example is creatine.
  3. Ergogenic supplements. If a supplement gives us the energy to move more, be more consistent with our workouts, or push ourselves harder while working out, then it can help us burn more calories and/or stimulate more muscle growth. A good example is caffeine.

Let’s go into each of those three categories in more detail.

Illustration of a tub of muscle-building supplements.

Introduction

In our article for skinny-fat guys, we talk about the five things you need to do if you want to build muscle, lose fat, and improve your body composition over time:

  1. Lift Weights
  2. Eat Enough Protein
  3. Get Enough Good Sleep
  4. Live a Generally Healthy Lifestyle
  5. Adjust Your Calorie Intake to Match Your Goals

There might be some magic bullets out there, but your body-fat isn’t a werewolf, and so it’s better slain by more conventional methods. Still, there some supplements that can make it easier to build muscle, easier to burn fat, and easier to achieve the elusive goal of doing both at once.

Protein Supplements

In this study, the participants were put on a weight training program and given a weight-loss diet. One group ate 0.5 grams of protein per pound bodyweight per day, and the other group ate twice that. For a 150-pound man, that’s 75 grams versus 150 grams of protein per day. Here’s what happened:

Graph showing that eating enough protein can help with muscle gain and fat loss (body recomposition)

Both groups lost a comparable amount of weight—around 8 pounds—but the group who ate enough protein gained 2.6 pounds of muscle, whereas the group that didn’t only gained 0.2. What this shows is that simply by eating enough protein, we can gain way more muscle while losing weight.

Now, do you need a supplement to help you eat more protein? Nope. You can get your protein from whole foods. And several whole foods are not only rich in protein, but also quite filling, which can make it easier to lose weight. Some good examples include lean cuts of red meat, chicken breast, and fish, greek yoghurt, pumpkin seeds, legumes, peas, and so on. But if you’re finding it hard to get your protein from whole foods, supplements can make it easier.

Whey protein is the gold standard of protein supplements. It’s minimally processed, has a perfect mix of amino acids for stimulating muscle growth, and it has a ton of research to prove its safety and efficacy (studystudy). But there are plenty of other good alternatives:

  • Pea/rice protein powder, which is ideal for plant-based diets.
  • Egg or beef protein powder, which are great for people who can’t eat dairy.
  • Casein protein powder, which is great to have before bed.
  • Protein bars, such as Quest Bars, which are more filling.

Just to reiterate, though, the important thing is making sure that you’re eating around a gram of protein per pound bodyweight per day, though. That’s what will help you gain or maintain muscle mass while losing weight. Supplements can make that easier, but you don’t need them.

How to take protein powders: have as much protein powder as you need to hit your daily protein targets. I’d try to get enough protein from whole foods that you only need 0–2 scoops of protein powder per day. Most people tolerate whey protein quite well, but if you get diarrhea, that can be a sign that you’re overdoing it. My favourite brand is Optimum Nutrition.

Muscle-Building Supplements

Creatine for Muscle Growth

Of all the muscle-building supplements, creatine is by far the most powerful (studystudystudystudy). It’s also the most widely researched, and the only known side effect is stomach cramping if you fail to consume it with enough water. In fact, it’s not only safe, it’s also a pretty good supplement for improving general health (studystudystudy).

Illustration of a bodybuilder flexing his muscles after doing compound lifts.

Some studies show creatine speeding up muscle growth by as much as 50%, at least in the first few weeks (study). That’s not uncommon, especially when you consider that creatine causes our muscles to swell up with extra fluid. After that initial period, creatine continues to help us build muscle, but the effects are less pronounced.

What’s neat about creatine is that it improves our results in a couple of complementary ways:

  • Creatine allows us to eke out a couple of extra reps when lifting in the moderate rep range (6-20 reps), which is the rep range that’s idea for building muscle. This can be a real boon when losing weight, which can make it harder to train as hard.
  • Creatine improves our ability to build muscle, allowing us to gain additional muscle mass. Again, this is a huge benefit when losing weight, as losing weight makes it harder to build muscle.

There are a few other supplements that have similar effects, with a notable example being beta-alanine. The effects are smaller and less reliable, though, and creates a sensation of being consumed by a horde of spiders. So we don’t typically recommend it unless someone is really enthusiastic about taking supplements.

Creatine, then, is one of the best supplements to take if you’re trying to build muscle while losing weight overall.

How to take creatine: the ideal dosage is 3–5 grams dissolved in a glass of water, taken once per day. It can be taken at any time of day, but we recommend first thing in the morning (which may help you wake up) or right after working out (which may slightly improve results). My favourite brand is AllMax.

Melatonin for Body Recomposition

There’s another supplement that often flies under the radar when people are trying to lose weight while gaining muscle: melatonin. In a recent study, 81 women took 1–3mg of melatonin before bed every night for a year and saw a 3.4% increase in muscle size. The placebo group, on the other hand, saw a 1.9% reduction in muscle size:

Graph showing that supplementing with melatonin increases muscle growth.

What’s even more impressive is that the melatonin group not only gained muscle, they also lost quite a bit of fat, especially when compared against the placebo group:

Graph showing that supplementing with melatonin causes fat loss.

Plus, these women weren’t lifting weights, eating more protein, or doing anything else. All they did was supplement with a bit of melatonin before bed, and it helped them build muscle while losing fat.

With that said, you don’t need to supplement with melatonin, you just need to get proper sleep. For example, if we look at this study, the participants were put on a weight training program and given instructions on how to improve their sleep. After only ten weeks, they were able to gain 3.7 pounds of muscle while losing 4 pounds of fat:

Graph showing simultaneous muscle growth and fat loss with sleep optimization.

How to improve your sleep: we recommend that you start by focusing on lifting weights (which improves sleep), eating enough protein (which improves sleep), and building a good sleep routine, as explained in our article on how to improve your sleep. If you’re still having trouble sleeping, melatonin might help, but you probably won’t need it.

Ashwagandha

A recent study came out showing that ashwagandha can help with building muscle, burning fat, reducing stress, and improving testosterone production. More specifically, the 8-week study found a 15% greater increase in testosterone and a 44-pound greater increase in bench press strength when compared to the placebo group, as well as some modest improvements to body composition.

Does this make ashwagandha a good supplement for building muscle while losing weight? Maybe! There don’t seem to be any real downsides to taking it. But the effects are fairly mild compared to creatine and getting enough good sleep each night.

Ergogenic Supplements

The most important part of building muscle is constantly striving to outlift ourselves. Every workout, we need to add a little bit of weight to the bar or fight for an extra rep. That’s how, over time, we become bigger, stronger, and more muscular.

Illustration of Milo of Croton carrying a calf as it grows into a bull, demonstrating the principle of progressive overload.

“Ergogenic” supplements improve our physical performance. For example, when you drink coffee, you feel more energetic, you can push yourself a bit harder, and you’re a bit less sensitive to the pain of working out. That can make it easier to outlift ourselves, which can lead to gradual increases in muscle mass over time.

Now, caffeine isn’t like creatine. It doesn’t directly improve our ability to build muscle. But it does help us show up to our workouts, give them our best effort, and enjoy them a bit more. If that’s a limiting factor for you, caffeine can help.

There are other supplements that fall into this category, kind of. Anything that you’d find in a typical pre-workout supplement or energy drink, such as theanine, taurine, or citrulline, might help a little bit. But there’s not very much research there, and the effects are likely modest.

How to take caffeine: most studies use fairly high doses of caffeine, and you probably wouldn’t want to imitate them, lest you interfere with your ability to get a good night’s sleep. I’d recommend sticking to coffee or tea, or perhaps a pre-workout supplement or energy drink when you really need it. Anecdotally, a lot of lifters swear by sipping on strong black coffee while lifting weights, myself included.

Summary

The most important parts of building muscle while losing weight are:

  1. Lifting Weights
  2. Eating Enough Protein
  3. Getting Enough Good Sleep
  4. Living a Generally Healthy Lifestyle
  5. Adjusting Your Calorie Intake to Match Your Goals
Illustration of a man losing weight while building muscle.

Still, some supplements make it easier to do those things. For example, protein powders make it easy to eat enough protein. Other supplements, such as creatine, improve our ability to build muscle. And others, like caffeine, can help us push ourselves in the gym, even when we’re tired.

The best supplements for building muscle while losing weight are:

  • Protein powders, such as whey: these supplements make it easier to eat more protein, allowing you to gain or maintain your muscle mass while losing weight.
  • Creatine: this supplement improves our workout performance, increases our lean mass, and improves our ability to gain muscle mass. It is, without a doubt, the most powerful muscle-building supplement.
  • Caffeine: which can improve energy, reduce fatigue, and make lifting a little bit less painful, especially when lifting in moderate rep ranges. This can help us push ourselves harder and increase our training volume.
  • Melatonin: this supplement is known for improving sleep, but your body can produce it naturally if you get into a good bedtime routine. I’d recommend starting there, only supplementing if you really need to.
Cover illustration of the Outlift intermediate bulking program for naturally skinny guys.

And, as always, if you want a customizable workout program (and full guide) that builds these principles in, check out our Outlift Intermediate Bulking Program. We also have our Bony to Beastly (men’s) program and Bony to Bombshell (women’s) program for skinny and skinny-fat beginners. If you liked this article, you’ll love our full programs.

Shane Duquette is the co-founder and creative lead of Outlift, Bony to Beastly, and Bony to Bombshell, and has a degree in design from York University in Toronto, Canada. He's personally gained 65 pounds at 11% body fat and has ten years of experience helping over 10,000 skinny people bulk up.

Marco Walker-Ng is the co-founder and strength coach of Outlift, Bony to Beastly, and Bony to Bombshell, and is a certified trainer (PTS) with a Bachelor's degree in Health Sciences (BHSc) from the University of Ottawa. His specialty is helping people build muscle to improve their strength and general health, with clients including college, professional, and Olympic athletes.