There is no recommended dosage for l-glutamine. Follow the manufacturers guidelines or seek advice from a doctor if you are unsure of the amount of glutamine to take.
There is debate as to the right dosage; it's advisable to start with a low dosage and see if positive benefits are gained before increasing dosage.
L-glutamine supplements are available as powders, capsules (usually 500mg), tablets (usually 500mg) or as a liquid.
As a guideline, the following brands of l-glutamine recommend these doses:
Nutrisport L-glutamine Tablets – 1000mg glutamine tablets – 1- 6 tablets daily between meals or after exercise.
More conservative dosage is recommended with:
All American EFX Pure Liquid Glutamine Elite – 15ml / 1 tablespoon – 3000mg of liquid glutamine per serving.
L-glutamine is a low calorie product with about 20 calories per teaspoon (4.5grams) and won't cause a significant rise in calorie intake at higher doses.
For general exercise, glutamine should be taken immediately after training when glutamine levels are lowered.
For general use, in tablet or capsule form, 3 x 500mg doses seems the norm but may be up to 4.5g a day based on some supplement brands recommendations. Body builders may sometimes increase dosage to 10-15 grams a day or even higher.
Glutamine does not need to be cycled and can be used on a daily basis without fear of tolerance by the body. Doses of glutamine can be added to liquid or food but make sure it is not hot as glutamine is destroyed by heat. Some body builders and athletes will mix glutamine with protein shakes; others may mix it with cold water.
L-glutamine supplements are well tolerated by the body and there are no known severe adverse side effects. In some cases, following larger doses of l-glutamine, a minor gastrointestinal disturbance (upset stomach) may be experienced.
L-glutamine is considered a safe supplement. At normal doses, there are very limited side effects. There are no known dangers of glutamine.
However, as when buying any health supplement, buy supplements of a reputable brand for a better quality product and reduced risk of contaminated batches.
There is no agreed dosage, or safe level of which l-glutamine can be taken. Up to 15g, divided through the day or even higher may be safe. Some body builders take much more than 15g a day.
There is always a chance that l-glutamine may interact with other drugs. However this may be a positive benefit of glutamine; evidence to date suggests glutamine can enhance the effectiveness of certain drugs in the treatment of cancer. Consult a doctor if you are thinking of taking this supplement and are currently on existing medication.
People with reduced kidney function, such as the elderly, should consider reducing the dosage.
Avoid exposing l-glutamine to heat as heat can destroy it.