The limited number of human studies involving oral AMP have not indicated any side effects. However, some researchers have expressed concern that supplemental intake of AMP could, in theory, increase levels of adenosine, a substance related to AMP that may interfere with immune function.⁶ Doctors using AMP injections report that too-rapid intravenous administration or inadvertent administration of an intramuscular injection into a vein could cause life-threatening arrhythmias of the heart.⁷