NADPH, Tetrasodium Salt is a ubiquitous cofactor and biological reducing agent that acts as an electron donor in many biological reactions. It is generated by reduction of the electron acceptor NADP+, and is very similar to another cofactor, NADH, which lacks a phosphate group at position 2' of the ribose moiety on the adenine half of the dinucleotide. This compound is involved in many pertinent biochemical pathways, including: formation of carbohydrate from CO2 during photosynthesis, maintenance of high levels of reduced glutathione in erythrocytes, reduction of thioredoxin, and formation of free radicals in immune cells which are used to destroy pathogens - aka the respiratory burst.