Muscle, Meals, and Myths: The Ultimate Dive into Glutamine

Unlock the secrets of glutamine and explore its wide array of benefits for fitness enthusiasts and everyday individuals alike.

What’s in this article:


Is Glutamine and L-Glutamine the Same?

At its core, glutamine is an amino acid that plays a pivotal role in various bodily functions. Many people often confuse glutamine with L-glutamine. While they are closely related, L-glutamine refers to the natural form of glutamine that is produced in our bodies and used in supplements. Simply put, when you hear about glutamine supplements or dietary recommendations, they often refer to L-glutamine. However, for the sake of clarity and simplicity, most people and professionals use the terms interchangeably.

It’s worth noting that the “L” in L-glutamine refers to its molecular orientation, representing the levorotatory form. In chemistry, many molecules come in mirror-image forms known as stereoisomers. While there’s also a D-glutamine, it’s less common and not utilized in the body the same way L-glutamine is. The body’s proteins predominantly utilize L-amino acids, making L-glutamine the preferred and more biologically active form.1 Therefore, when considering dietary supplements or food sources, focusing on L-glutamine ensures you’re harnessing the benefits most relevant to human health.

Why Glutamine is Important

Glutamine is crucial for multiple reasons. It aids in the proper functioning of our immune system, ensuring we can fend off infections and illnesses. Additionally, this amino acid is essential for the health and repair of our intestines. For athletes and those involved in rigorous physical activity, glutamine helps in muscle recovery, preventing muscles from breaking down after intensive workouts.2. Furthermore, glutamine can be a vital energy source for our cells, especially when the body is under physical or emotional stress.

Glutamine also supports optimal brain function. It serves as a precursor for the neurotransmitter glutamate, which plays a vital role in cognitive functions such as learning and memory.3 Additionally, glutamine has been shown to aid in maintaining the integrity of the blood-brain barrier, a protective barrier that regulates what substances in the bloodstream can access the brain. Disruptions in this barrier are linked to various neurological disorders. Therefore, an adequate supply of glutamine not only fortifies our physical well-being but also bolsters our neurological health.

Where Glutamine is Produced in the Body

Glutamine is primarily synthesized in our muscles. These muscles release glutamine into the bloodstream, where it’s transported to organs and tissues that need it the most, such as the lungs, liver, and brain. Moreover, the small intestines, another key player in glutamine production, utilize a significant amount of glutamine for their functions. These processes underline how integrated and essential glutamine is in maintaining overall health and bodily harmony.

Just as a delivery driver shuttles packages from one place to another, glutamine whizzes around our body, ensuring organs get their much-needed supply. Like dropping off ingredients to our favorite pizza place, glutamine ensures our brain, lungs, and liver get what they need to function at their best. Plus, our small intestines absolutely love it – they gobble up glutamine like it’s their favorite snack. In this bustling city of bodily functions, glutamine is our ever-reliable transporter, ensuring everything runs smoothly and everyone stays happy!

How Glutamine Works for Bodybuilding

For bodybuilders and fitness enthusiasts, glutamine is often termed the “building block of protein.” It aids in muscle protein synthesis, which is the process of building new proteins or repairing damaged ones. This not only promotes muscle growth but also minimizes muscle breakdown during intensive workouts.4 Another vital aspect is its ability to replenish glycogen, a primary energy reserve in our muscles. Post-exercise, consuming glutamine can speed up glycogen synthesis, leading to quicker recovery and enhanced performance in subsequent workouts.

Optimal Timing for When Should Glutamine Be Taken

Ideal glutamine consumption depends on individual goals and routines. For those focusing on muscle recovery and reducing muscle soreness, it’s recommended to take glutamine post-workout. This can aid in replenishing the body’s depleted glutamine levels, thus facilitating faster muscle repair. However, some individuals prefer taking it before their workouts as they believe it provides an energy boost, although the evidence on this is not conclusive.

For those who are not athletes or aren’t regularly involved in rigorous physical activities, glutamine can still offer benefits when taken at specific times. It’s often recommended to consume glutamine on an empty stomach to ensure optimal absorption, either first thing in the morning or just before bedtime. Taking it before bed can support overnight muscle recovery and potentially boost growth hormone levels. However, it’s essential to keep in mind that everyone’s body is unique. Just as some people swear by their morning coffee and others prefer an afternoon cup, finding your ideal glutamine schedule might require a bit of trial and error. And, as with anything, moderation is key to reaping the maximum benefits without any unwanted side effects. Always consider consulting with a health professional or nutritionist to determine the best timing for your needs.

Will Glutamine Help with Weight Loss?

Glutamine’s role in weight loss isn’t direct, but it can potentially aid the process. By supporting muscle recovery and growth, it can increase the body’s resting metabolic rate, leading to a higher calorie burn. Additionally, maintaining muscle mass can be essential during calorie-restricted diets, ensuring the weight loss is primarily from fat.5 While it’s not a miracle weight loss supplement, when combined with a balanced diet and exercise, it can complement the weight loss journey.

Foods Rich in Glutamine

Glutamine is abundantly found in a variety of foods. Animal proteins such as beef, chicken, fish, and eggs are excellent sources. For vegetarians and vegans, beans, lentils, and dairy products can offer significant glutamine content. Additionally, some vegetables, including spinach and parsley, are also packed with this amino acid. It’s always beneficial to include a mix of these foods in one’s diet to ensure adequate glutamine intake.

If you’re keen on boosting your glutamine intake without supplements, experimenting with diverse culinary creations can be both fun and beneficial. Imagine whipping up a hearty lentil soup with a side of spinach salad or grilling a piece of salmon with a sprinkle of parsley. For breakfast enthusiasts, an omelette loaded with veggies can give you that early morning glutamine kick. Even smoothies can be a fantastic choice; blend in some spinach, Greek yogurt, and a handful of nuts to get a tasty and nutritious glutamine-rich drink.

Other Benefits of Glutamine

Beyond muscle recovery and gastrointestinal health, glutamine has more to offer. It’s pivotal in the production of other amino acids, glucose, and even certain neurotransmitters. Some research suggests that glutamine can support a healthy immune response, potentially reducing the severity and duration of certain illnesses.6 Moreover, given its role in gastrointestinal health, glutamine might aid in maintaining a balanced gut flora, integral to digestion and nutrient absorption.

Who Should or Shouldn’t Take Glutamine?

While glutamine supplements can be beneficial, they aren’t for everyone. Athletes, bodybuilders, or individuals with a strenuous workout regimen might find them useful. However, those with liver disease, kidney disease, or Reye’s syndrome should avoid glutamine supplementation. Pregnant or nursing women, or those on specific medications, should consult a healthcare professional before incorporating glutamine supplements into their routine.

Potential Glutamine Side Effects

In general, glutamine is well-tolerated when taken in recommended doses. However, like any supplement, excessive consumption might lead to adverse effects. Some people have reported symptoms like nausea, vomiting, stomach pain, or allergic reactions. It’s paramount to adhere to suggested dosages and always start with a lower dose to gauge individual tolerance. Remember, the key to supplementation is moderation and personal suitability.

Glutamine Focused Pre and Post Workout Meals


  1. Spinach and kale smoothie with a scoop of protein powder.
  2. Grilled chicken salad with mixed greens and vinaigrette.


  1. Lentil soup with assorted vegetables.
  2. Baked salmon with a side of quinoa and steamed broccoli.

Always remember, diet and supplementation are personal. What works for one might not work for another. Consultation with a dietitian or healthcare professional can ensure that you’re making the best choices for your body.

Choosing What is Best For Your Body

Hopefully, after reading this you’re ready and more informed about the glutamine supplement and its advantages and disadvantages for your fitness and health journey. Understanding the role and benefits of specific amino acids like glutamine can feel overwhelming. However, armed with knowledge and insights, making informed decisions becomes a simpler task. Whether you’re an athlete aiming for optimal muscle recovery or someone keen on boosting overall well-being, glutamine offers a wealth of benefits. If you choose to incorporate it, either through diet or supplementation, and consulting professionals when in doubt, you’re taking a proactive step toward a healthier, more vibrant you.


  1. Tina M. St. John, Chapter 21 – Chronic Hepatitis, Editor(s): David Rakel, Integrative Medicine (Fourth Edition), Elsevier, 2018, Pages 198-210.e5, ISBN 9780323358682
  2. Bowtell JL, Gelly K, Jackman ML, Patel A, Simeoni M, Rennie MJ. Effect of oral glutamine on whole body carbohydrate storage during recovery from exhaustive exercise. J Appl Physiol (1985). 1999;86(6):1770-1777. doi:10.1152/jappl.1999.86.6.1770
  3. Ménard, C., & Quirion, R. (2012, September 23). Group 1 metabotropic glutamate receptor function and its regulation of learning and memory in the aging brain. Frontiers.
  4. Varnier M, Leese GP, Thompson J, Rennie MJ. Stimulatory effect of glutamine on glycogen accumulation in human skeletal muscle. Am J Physiol. 1995;269(2 Pt 1):E309-E315. doi:10.1152/ajpendo.1995.269.2.E309
  5. Roth E. Nonnutritive effects of glutamine. J Nutr. 2008;138(10):2025S-2031S. doi:10.1093/jn/138.10.2025S
  6. Castell LM, Poortmans JR, Newsholme EA. Does glutamine have a role in reducing infections in athletes? Eur J Appl Physiol Occup Physiol. 1996;73(5):488-490. doi:10.1007/BF00334429


We work hard to provide the most up-to-date, accurate and authoritative health and wellness knowledge so you can live your best life.