L-Glutamine, the versatile amino acid

L-Glutamine is an important amino acid, found in abundance throughout the body, and is a key energy source for many tissues in the body. It's involved in more metabolic processes than any other amino acid. L-Glutamine is an important antioxidant that plays a major role in healthy digestive, immune, nervous system and muscle function.

L-Glutamine and glutamine

L-Glutamine is the naturally occurring form of the amino acid glutamine. The names L-Glutamine and glutamine are often used interchangeably. L-Glutamine is one of the only amino acids that can cross the blood-brain barrier. L-Glutamine can be found in both animal and plant-based proteins, including whey protein, meat, chicken, fish, eggs, beans, cottage and ricotta cheese, dairy products, rolled oats, soybeans and fermented foods. L-Glutamine, is usually a 'conditionally' essential amino acid, but becomes 'essential' when stores have been depleted, particularly after periods of physical stress.

The role of L-Glutamine in the body

Digestive health

L-Glutamine is necessary for maintaining the intestinal mucosa where it helps to maintain the integrity of the intestinal lining and supports normal gut barrier function and permeability. The intestinal lining acts a selective barrier, allowing important dietary nutrients, electrolytes and water to enter the bloodstream, while at the same time preventing the passage of foreign substances, such as food antigens, toxins and harmful pathogens, into the bloodstream.
When the intestinal lining becomes damaged, these foreign substances 'leak' into the bloodstream, triggering immune system activation and inflammation. Damage to the intestinal lining is often referred to as 'leaky gut'. L-Glutamine is the preferred fuel source for intestinal absorptive cells so it supports intestinal health. Depletion of L-Glutamine can negatively affect gut barrier function, resulting in impaired intestinal permeability. See Herbs of Gold Gut Care.

Immune health

Around 80% of the immune system sits within the gastrointestinal tract and L-Glutamine makes a significant contribution to maintaining gut-associated lymphoid tissue (GALT), part of the gastrointestinal immune system. L-Glutamine is an important fuel source for the rapidly multiplying cells of the immune system. It helps support white blood cell function and is particularly beneficial after periods of physical stress. Following strenuous exercise, L-Glutamine levels can be depleted by around 20%, resulting in immunodepression. L-Glutamine also helps to maintain secretory IgA, an immune marker, which functions primarily to prevent the attachment of bacteria to the mucosal cells of the gut. See Herbs of Gold Gut Care.

Nervous system health

L-Glutamine helps maintain healthy nervous system function. As L-Glutamine can cross the blood-brain barrier, it is readily taken up by the brain and converted into gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter that helps calm the central nervous system. See Herbs of Gold L-Glutamine 750.

Muscle health

L-Glutamine is primarily stored in skeletal muscles and helps maintain muscle health after exercise by maintaining glutamine muscle levels post-exercise. Requirements for glutamine may be increased in athletes and active individuals. See Herbs of Gold Muscle Resuscitation.


L-Glutamine is an important antioxidant and the precursor for the synthesis of glutathione, the body's master antioxidant. As an antioxidant, L-Glutamine protects the body from free radical damage and oxidative stress and is important for removing excess ammonia (a common waste product in the body). See Herbs of Gold L-Glutamine 750.


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