Glutamine is one of the most abundant amino acids in the body, but under certain conditions, supplementation may be necessary, so understanding all of its potential effects is important.
What is Glutamine?
Glutamine is a non-essential or conditionally essential amino acid that is commonly used in the synthesis of proteins within the body. Often referred to as L-glutamine, it is produced naturally within the body. Some health conditions cause the demand for this amino acid to rise, such as intense stress or the need for healing and recovery. In those cases, your amino acid supply can be supplemented with certain foods that are rich in this compound, or even glutamine supplements. Fortunately, it is found in moderate amounts from both plant and animal sources, making it easy to naturally boost your diet. 
In most cases, this supplement comes in the form of a powder, and is popular with weightlifters and athletes, as it is known to help preserve muscle tissue and promote rapid growth. It is generally considered safe for consumption, although it does have certain side effects when taken in excess, or when you are already suffering from certain pre-existing conditions.
A few of the top benefits of glutamine in the body include the following:
- Better digestion
- Improved muscle growth
- Boosted metabolic speed
- Treatment of diabetes
- Anticancer Potential
- Treatment of ulcers
- Increased endurance
- Weight loss
If you are suffering from any stomach issues, from leaky gut syndrome to a bad case of diarrhea, the stomach-boosting properties of glutamine can help. Functioning as a fuel source for the cells in the small intestine, it can optimize gut health and minimize damage to the intestinal lining, which can prevent certain autoimmune diseases. 
One of the cases in which consuming a glutamine supplement may be necessary is in the case of ulcers, which is basically when the lining of your stomach or duodenum begins to break down. Additional amounts of this amino acid can stimulate healing and regrowth of those damaged cells. 
As a key component in protein biosynthesis, this amino acid is required to build the additional cells and tissues following strenuous weightlifting. Supplementation is often practiced by bodybuilders for this reason. 
If you regularly work out, then you are regularly draining your glutamine supply from your body so supplementation may be necessary to maintain endurance and get the best results from your exercise. Studies have also found that this supplement can increase muscle hydration and protect against injury. 
This amino acid is critical to metabolic function since it is the most widely available free amino acid in the bloodstream; the versatility and high demand for glutamine mean that it is constantly being used for essential daily processes. 
A report published in the American Journal of Surgery suggests that extra glutamine in the body can help slow, stop or reverse tumor growth in the case of certain cancers. When glutamine is given alongside radiation or chemotherapy, it protects the host and increases the selectivity of therapy for the tumor. 
Studies have found that this amino acid can suppress insulin levels and regulate blood glucose, which is important for those with diabetes, or for people at high risk of developing the condition. 
By providing a major boost to human growth hormone (HGH) levels, the metabolism of the body is sped up, leading to more effective fat-burning and additional weight loss. This is in addition to glutamine’s ability to suppress food cravings. 
Best Glutamine Foods
Glutamine can be found in many foods, especially animal products as they contain a high level of protein. Under normal circumstances, your body can produce all of the glutamine you need, but you can also supplement its deficiency with foods that are rich in this amino acid, such as the following:
- Chinese cabbage
- Broccoli rabe
- Bone broth
- Beans and legumes
- Dairy products
- Whey protein
If you have been advised to take supplements of this amino acid, most experts recommend between 5 and 25 grams per day, depending on what conditions you are trying to ameliorate. If you take more than 50 grams of this supplement, it is possible to increase the ammonia levels in the body, which can come with other unwanted side effects.
Glutamine Side Effects
This amino acid is responsible for many health benefits, but there are some side effects, such as the following: 
- Complications of pregnancy: Due to a lack of research, it could be dangerous to take these supplements while pregnancy or nursing.
- Stomach issues: For those who have sensitive stomachs, this supplemental powder has been known to cause nausea, vomiting, and headaches, and even seizures in a few rare cases.
- Liver problems: If you already have liver disease, excessive glutamine intake can worsen the condition.