Good Nutritional Balance of Feeds. L-Threonine is an essential amino acid. Please consult your doctor before starting any exercise or nutritional supplement program or before using these or any product during pregnancy or if you have a serious medical condition. You may also experience symptoms of liver problems. Regardless of your situation you may want to consider taking an L-threonine supplement if you follow a vegetarian or vegan diet since these are often low in protein. Taking this supplement might help your liver stay healthy boost your immunity and increase energy. L-threonine itself is the only active ingredient in this product making it less likely to cause interactions with other supplements.