Look beyond protein to the variety of other supplements you can use to promote muscle growth. Expert nutritionist Laura Jennings has plenty of alternatives.

If you’re looking to build muscle in a bid to get in shape, supplements could be the way to go. The chances are you’ve used fitness supplements before, even though you might not have known it. From packing a protein shake in your gym bag to chugging the occasional isotonic sports drink, it’s likely you’ve supplemented your day-to-day nutrition while trying to stay in shape or recover from one workout to the next.

The trouble is that looking for the best supplements can get mighty confusing, especially as each manufacturer wants to convince you their products is better filtered, or more efficient, or will boost muscle growth the most. As you look around for the right product for you, you might feel as if you need a degree in chemistry to understand what you’d be putting into your body.

The science behind some of the best supplements for muscle growth may be slightly baffling, but we’ve done the hard work so you don’t have to. We’ve trawled through the latest developments in supplement science to dig out the important stuff: what you need, when you need it and why.

It’s possible you’ll find a supplement to send your training gains through the roof, or just learn a bit more about the products you’re already using. Either way, next time you put in the hard yards at the gym, you’ll know you’re getting the nutritional back-up you need.

BCAA powder with scoop


The benefits of BCAAs – otherwise known as branched-chain amino acids – are numerous. They’re the best supplement to take during workouts because they help to keep a steady supply of proteins flowing into your muscles.

If you’re looking for the best supplements for lean muscle growth, BCAAs are a great place to start. This helps with muscle building as it reduces the amount of muscle loss during exercise and improves protein synthesis, the process by which new muscle tissue is built.

BCAAs can also help to prevent muscle loss during periods of intermittent fasting.

NUTRITIONIST SAYS: “In my role as a registered nutritionist,” says Laura Jennings, “I support the utilization of BCAA (branched-chain amino acid) supplements for their indispensable role in muscle protein synthesis. The combination of leucine, isoleucine, and valine in BCAAs facilitates muscle recovery, alleviates exercise-induced muscle soreness, and helps maintain lean muscle mass. Particularly advantageous for those involved in rigorous workouts, BCAA supplements offer efficient muscle support.” 

Try Optimum Nutrition’s Gold Standard BCAA

2. Creatine

Your body metabolises creatine into ATP, which is used for every initial muscle movement.

It’s therefore vital to have adequate supplies when you’re doing heavy, high-intensity workouts in order to deliver the required energy to your muscles.

In other words, you should consider taking creatine if you’re looking to lift harder for longer, as it’s one of the best supplements for significant muscle growth.

NUTRITIONIST SAYS: “By replenishing ATP stores,” says Jennings, “creatine fuels short bursts of intense energy, boosting performance during high-intensity activities like weight lifting and sprinting. This supplement’s ability to draw water into muscle cells may contribute to cell volumization, further supporting muscle growth. I find creatine supplements to be a reliable and well-researched option for those seeking improved strength, enhanced workout capacity and accelerated muscle recovery.”

Try Protein Works’ Creatine Extreme

3. Leucine

The most anabolic amino acid, leucine can independently stimulate insulin secretion and muscle protein synthesis, enhancing the muscle-building process.

At 11%, the best whey protein powders are very high in leucine content, which is one reason it’s so effective as a post-workout elixir.

NUTRITIONIST SAYS: “Leucine supplements play a pivotal role in the intricate process of muscle protein synthesis, aiding in the repair of muscle tissue post-exercise,” explains Jennings. “As a key trigger for this process, leucine is essential for bolstering muscle strength and overall performance, making it a valuable supplement for those engaged in strength training or aiming to preserve muscle mass.

“Research shows that pairing leucine supplements with complimentary nutrients, such as vitamin D, maximises performance benefits. Incorporating leucine supplements into a well-rounded diet proves especially advantageous, facilitating efficient muscle development and fostering a speedy recovery post-exercise.”

Try Applied Nutrition’s Leucine 4K

4. L-carnitine

If burning fat during a workout is your priority, first you need to mobilise it.

L-carnitine is an amino acid responsible for transporting fatty acids into the mitochondria, our cells’ energy powerhouses. This makes it one of the best supplements for lean muscle growth.

NUTRITIONIST SAYS: “L-carnitine supplements are celebrated for their integral role in energy metabolism, facilitating the conversion of fat into a usable energy source,” says Jennings. “That’s especially advantageous for highly active individuals and those focused on weight management. Integrating L-carnitine may effectively support increased energy levels and optimise fat and glycogen utilisation during physical activity. L-carnitine’s association with enhanced exercise performance, potential fatigue reduction, and improved recovery make it a noteworthy addition to any training plan.”

Try Solgar’s liquid L-carnitine

Foods rich in glutamine – one of the best supplements for muscle growth

5. L-glutamine

This amino acid should be present in your body, but if you have problems with your digestion or are training hard, a supplement can help to strengthen the lining of your gut and help protein synthesis.

NUTRITIONIST SAYS: “As a nutritionist, I emphasize the crucial role of L-glutamine, the predominant amino acid in plasma and skeletal muscle, in post-workout recovery and overall exercise performance,” says Jennings. “After intense physical activity, glutamine levels decline, posing a risk to normal plasma levels and inviting protein breakdown. This decline is often associated with compromised immunity after prolonged exertion.

“L-glutamine supplements are instrumental in fortifying immune system health, defending against infections and preserving muscle mass post-exercise. Additionally, these supplements aid in mitigating gut damage, promoting overall gut health. Incorporating L-glutamine into your routine is advantageous for those seeking heightened physical resilience.”

Try the Reflex Nutrition’s L-glutamine

6. Magnesium

Every organ needs magnesium, especially the heart, muscles and kidneys. If you skimp on this vital mineral you can experience anxiety, sleep problems and irritability.

Magnesium also helps to maintain a normal heart rhythm and aids in the body’s energy production.

NUTRITIONIST SAYS: “Magnesium supplements offer myriad health benefits,” says Jennings. “As a vital mineral, magnesium is involved in over 300 biochemical reactions within the body, including energy production, muscle function, and nerve transmission.

“Supplementing with magnesium can support cardiovascular health by helping regulate blood pressure and reducing the risk of heart disease. In my opinion, integrating magnesium supplements is a valuable strategy for overall health, addressing key aspects of energy metabolism, cardiovascular function and sleep quality.”

Try BetterYou’s Magnesium Spray

7. Multivitamins

Whether or not you should take multivitamins is always a difficult question. Although you shouldn’t rely on them to make up for a bad diet, a quality multivitamin can help to fill in the gaps in an otherwise solid eating plan.

Deficiencies in vitamins can cause mood swings, depression, lethargy and exhaustion, but taking a daily dose will keep you on the up and focused on your goals. There is also evidence a multi-vitamin can help you recover from a tough workout. So, if you’re looking for the best supplements for muscle growth, taking a good quality multivitamin is a great place to start.

NUTRITIONIST SAYS: “Multivitamins provide a convenient way to address potential nutrient gaps in one’s diet, offering a diverse range of essential vitamins and minerals,” says Jennings. “This supplementation is especially beneficial for individuals with busy lifestyles or dietary restrictions. A well-formulated multivitamin supports energy production, physiological functions, immune function and overall vitality.”

Try Centrum Performance’s Multivitamin Tablets

8. Fish Oil

It’s important to include omega-3 fats in your diet for health reasons, and a supplement can help you to maintain a good ratio of omega-3 to omega-6 – most of us consume too much of the latter.

Studies have shown fish oil supplementation results in decreased body fat and reduced inflammation. It has also been linked with increased serotonin levels, more focus in training and less stress.

NUTRITIONIST SAYS: “Fish oil supplements, abundant in omega-3 fatty acids EPA and DHA, provide diverse health benefits,” says Jennings. “These essential fatty acids foster heart health by lowering triglycerides and promoting optimal blood vessel function. The supplements’ anti-inflammatory properties also contribute to relieving joint pain and stress-induced inflammation.

“Moreover, incorporating fish oil enhances cognitive functions such as learning, memory and overall brain health. From a professional’s view, omega-3 supplements are not only well-tolerated but also present a secure and advantageous option for cognitive enhancement and inflammation management.”

Try Nature’s Bounty’s Fish Oil

9. Vitamin D

You should get your vitamin D from the sun, but that’s a forlorn hope for the average desk-bound Briton – 20 minutes’ exposure is enough in the summer, but according to the National Institute of Health it’s impossible to get enough come the winter.

Deficiency is common and linked to lower strength levels and increased body fat, so it’s important to top up your levels with supplements if you want to boost your muscle growth – and overall health. Low vitamin D levels have also been associated with a number of diseases, including diabetes and depression. So you can see why it’s important to consider taking the best vitamin D supplements.

NUTRITIONIST SAYS: “As a nutritionist, I often highlight the importance of Vitamin D, often referred to as the ‘sunshine vitamin’ for overall health,” says Jennings. “It plays a pivotal role in calcium absorption, promoting strong bones and teeth. Adequate vitamin D levels are linked to immune system support, reduced inflammation, and a lowered risk of chronic diseases.

“While sunlight exposure is a natural source, supplements become essential, especially in regions with limited sun exposure. Ensuring optimal vitamin D levels is paramount for maintaining overall wellbeing, making it a cornerstone supplement for individuals of all ages.”

Try the BetterYou DLux Vitamin D Oral Spray

10. Green Tea

This is one of the best natural fat-burners around and can give your metabolism a jolt, making it one of the best supplements to augment your muscle growth journey.

Green tea is also packed with antioxidants and regular consumption has even been linked to reducing the risk of a range of conditions, including heart disease and Alzheimer’s.

NUTRITIONIST SAYS: “Green tea stands as a robust antioxidant source, abundant in catechins such as EGCG,” says Jennings. “These natural polyphenols harbour anti-inflammatory traits, bolstering cardiovascular wellbeing and potentially lowering the risk of specific cancers.

“The infusion’s moderate caffeine levels deliver a smooth energy lift without the jitters, heightening cognitive function. Additionally, green tea aids weight management by elevating metabolism and energy expenditure. The presence of L-theanine, a calming amino acid, promotes relaxation without inducing drowsiness, rendering green tea my ideal morning elixir for a gentle and refreshing start to the day.”

Try Twinings Pure Green Tea