Optimum Nutrition Glutamine supplement is a fantastic way to help support muscle repair and reduce muscle soreness - Extremely helpful for those in long term training. Glutamine is an essential amino acid, required by your muscles. Therefore it is also one of the most vital building blocks in forming the proteins - That in turn help to repair muscle tissue. Optimum Nutrition L-Glutamine Powder can be taken at any time. However it would be beneficial to take 3 times per day; first thing in the morning, pre/ post workout and before bed.The Optimum Nutrition Glutamine supplement is easy to take and can be mixed into your favourite drink.