Inosine

Inosine is a purine nucleoside — the direct deamination product of adenosine — that serves as a critical intermediate in the adenine nucleotide interconversion pathway, bridging AMP catabolism and de novo purine synthesis. During high-intensity exercise or hypoxic stress, AMP is rapidly degraded to IMP (inosine monophosphate) and then to inosine, which is released into the bloodstream. Inosine supplementation maintains the purine nucleoside pool required for efficient ATP resynthesis via the purine salvage pathway, allowing faster restoration of depleted muscle adenine nucleotide levels. Additionally, inosine is converted to uric acid, which serves as the most abundant antioxidant in human blood — accounting for approximately 60% of plasma antioxidant capacity — protecting red blood cells and neuronal membranes from oxidative damage during ischaemia-reperfusion stress.