In 2024, creatine rose in popularity as a fitness supplement, but in 2025, the hottest supplement is expected to be leucine. Dr. Erin Barrett, PhD and Sr. Director of Innovation and Scientific Affairs at , anticipates leucine will become 2025’s “it” supplement. Leucine, an essential amino acid, is pivotal in creating muscle protein and is used by athletes and bodybuilders to enhance muscle development and aid in recovery.
Dr. Barrett has shared her thoughts and predictions on this upcoming trend and how she recommends using leucine as a supplement for muscle growth. Dr. Barrett is an expert in nutrition, metabolic biochemistry, and associated diseases, including obesity and diabetes. At Shaklee, she is responsible for translating science into an innovation pipeline. Dr. Barrett has a PhD in Nutritional Biochemistry from the University of North Carolina at Chapel Hill, an MS in Clinical Research from Indiana University, and an MS in Biochemistry and Molecular Biology from Georgetown University. Now, let’s dive in.
What is leucine?
Leucine, an essential amino acid, is pivotal in creating muscle protein. It’s a preferred supplement among athletes and bodybuilders to enhance muscle development and aid in recovery — however, Dr. Barrett reminds us that leucine is not a new ingredient and has been well established as an effective way to stimulate muscle protein synthesis during the 1980s and 1990s.
“Its role as an essential amino acid means it must be obtained through diet or supplementation, and it plays a critical role in building and repairing muscle,” she said. As such, Shaklee has incorporated leucine into its products since the early 2000s.
Why is leucine getting so much attention?
Dr. Barrett anticipates the “hype” around leucine will continue to grow as “people become more aware of the importance of protein for building and maintaining muscle mass. Protein is made up of building blocks called amino acids. While all amino acids are needed to make proteins in the body, including those in muscle, leucine stands out because it’s the only one that directly triggers muscle protein synthesis.”
“This means that leucine activates the process in which the body repairs and builds new muscle tissue. This unique ability makes leucine particularly effective in promoting muscle growth, repair, and recovery, which are essential for maintaining strength, mobility, and overall health as we age,” she explained.
Benefits of leucine
Getting enough leucine in your diet offers various benefits, such as:
- Blood sugar stabilization
- Build and repair muscle tissue
- Improved fitness recovery, decreased muscle soreness
Who should take leucine?
According to Dr. Barrett, many people with different goals can benefit from taking leucine. Two of the main groups include anyone looking to achieve and maintain a healthy body weight and athletes and fitness enthusiasts.
Achieving and maintaining a healthy weight
First and foremost, she recommends supplementation with leucine for those focused on achieving and maintaining a healthy weight. “If you’re working to lose weight, leucine is a valuable tool for supporting fat loss while protecting lean muscle. When you reduce calories, your body typically breaks down fat and muscle for energy. Losing muscle during weight loss is problematic because muscle burns more calories — even at rest.” Dr. Barrett noted.
As losing muscle slows down your metabolism, it becomes “harder to keep the weight off you have worked hard to lose and unfortunately also easier to regain, which can lead to the vicious cycle of yo-yo dieting.” As such, leucine can help your body prioritize fat loss and preserve lean muscle to keep your metabolism thriving.
Athletes and fitness enthusiasts
Another group of people who can benefit from supplementing with leucine are athletes and fitness enthusiasts who want to build strength and accelerate their recovery post-workout. “For individuals who engage in strength training, endurance sports, or any regular physical activity, leucine is critical for muscle growth, recovery, and performance. Tiny tears form in your muscle fibers during exercise, especially resistance training. Repairing these tears allows your muscles to grow stronger and adapt to physical stress,” Dr. Barrett said.
“Leucine kick-starts this repair process by triggering protein synthesis. It provides your muscles the support they need to recover, grow stronger, and build endurance.”
Getting leucine in your diet
In addition to supplementing with leucine, adding extra protein-rich foods into your diet can help you get more leucine naturally. To boost leucine in your diet, Dr. Barrett recommends the following healthy sources:
- Animal proteins: Chicken, turkey, beef, fish, eggs, and dairy (milk, cheese, yogurt)
- Plant-based sources: Soy (tofu, tempeh, edamame), lentils, chickpeas, quinoa, and nuts
- Supplements: Whey protein, along with Shaklee products like Life Shake, and snack bars, which contain added leucine to support muscle recovery and growth
Shaklee has recently crafted some new products to add to their already extensive line, each of which contains 9 to 20 grams of protein per serving, lots of healthy fiber, and of course, a healthy dose of leucine.
