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Leucine: Benefits, Doses and Side Effects Explained

Leucine: Benefits, Doses and Side Effects Explained

Article At A Glance

Leucine is a potent activator for muscle building and repair, making it a popular supplement among athletes and fitness enthusiasts.

Supplementing with leucine can help maintain muscle mass, increase power output, and promote muscle growth.

The optimal dose of leucine depends on several factors, but on average, it tends to be supplemented in the range of 2,000 – 5,000mg.

Product Recommendations
Platinum Blend by UM Sports
Resurrect by UM Sports
Amino Switch by Switch Nutrition

Health and fitness enthusiasts use sports supplements to maximize their performance, health, and recovery. 

Not surprisingly, the amino acid Leucine is becoming an essential part of athletes' supplement regimes, specifically for those looking to build and repair muscle.

Keep reading to uncover Leucine's benefits, optimal dosage, and side effects.

What is Leucine?

The primary benefit of the three BCAAs (Leucine, isoleucine, and valine) is their ability to enhance muscle growth and alleviate muscle fatigue.

Of all the amino acids, Leucine is the most potent activator of muscle protein synthesis(MPS), which involves the creation of new muscle tissue and repairing damaged muscle fibres (from workouts, injury, and illness). 

The body cannot make essential amino acids; therefore, it is crucial to consume them daily through foods such as meat, poultry, fish, eggs, and milk.

Benefits of Leucine

Leucine has many benefits, especially when it comes to building muscle for athletes and fitness enthusiasts alike.

Here are some of the key benefits when it comes to supplementing with Leucine:

  • Promotes muscle growth and repair: Studies have shown that leucine supplementation helps to increase muscle protein synthesis (Blomstrand et al., 2006). This results in an increase in muscle mass over time when optimal levels of leucine are consumed daily.
  • Helps maintain muscle mass: As we age, we may experience an increase in muscle loss, also known as sarcopenia. According to studies, Leucine supplementation may help counteract this process, helping maintain healthy muscles for longer (Hao et al., 2022).
  • Regulates cellular processes: Processes such as protein synthesis, tissue regeneration, and metabolism. Therefore, in addition to its performance and recovery benefits, Leucine supplementation may benefit a variety of conditions such as aging, muscle lesions, protein/energy deprivation, obesity, and diabetes mellitus (Pedroso et al., 2015).
  • Increase power output: Although it’s most likely attributed to Leucine’s potent ability to stimulate MPS, studies have underscored its ability to enhance strength performance during resistance training (Ispoglou et al., 2011).

Optimal Dose of Leucine

The optimal dose of leucine depends on several factors, including your age, weight, and activity level.

On average, Leucine tends to be supplemented in the dose range of 2,000 – 5,000mg range (Frank et al., 2019).

This dose can be met by consuming high-quality whey protein or amino acid supplements, and through foods that are high in leucine, such as meat, fish, and dairy products.

If you’re looking for a high protein supplement that can hit your Leucine goals, we recommend UM Sports Platinum Blend or Resurrect Growth and Recovery Matrix!

Side Effects of Leucine

Leucine is generally considered safe for most people when consumed in recommended doses. However, some people may experience side effects such as nausea, diarrhea, and stomach discomfort when taking high doses of leucine.

It is important to follow the recommended dose guidelines and consult with a healthcare professional before starting any new supplement.

The Takeaway

Leucine is a beneficial supplement for athletes and fitness enthusiasts looking to enhance their muscle growth, recovery, and power output. The optimal dose of leucine varies based on individual factors, and it is important to consult with a healthcare professional before starting any new supplement.

If you are looking for a reliable sports supplement brand in Australia, be sure to do your research and choose a reputable company that adheres to quality standards.


  • Hao, Z., Xu, G., Yuan, M., Tan, R., Xia, Y., Liu, Y., & Yin, X. (2022). Leucine Supplementation in Middle-Aged Male Mice Improved Aging-Induced Vascular Remodeling and Dysfunction via Activating the Sirt1-Foxo1 Axis. Nutrients, 14(18), 3856–3856.
  • Ispoglou, T., King, R. F. G. J., Polman, R. C. J., & Zanker, C. (2011). Daily L-Leucine Supplementation in Novice Trainees During a 12-Week Weight Training Program. International Journal of Sports Physiology and Performance, 6(1), 38–50.
  • Pedroso, J. A., Zampieri, T. T., & Donato, J., Jr (2015). Reviewing the Effects of L-Leucine Supplementation in the Regulation of Food Intake, Energy Balance, and Glucose Homeostasis. Nutrients, 7(5), 3914–3937. 


Stephen Brumwell, Nutritionist (ANTA #40048)

Teigen Faux, Exercise Physiologist (Honours) for Scientific Accuracy

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