5-Aminolevulinic acid hydrochloride (5-ALA) serves as an intermediate in the body's heme biosynthesis and is the universal precursor of tetrapyrroles.

5-Aminolevulinic acid is an intermediate in heme synthesis which is the first compound in the porphyrin synthesis pathway.It is a photosensitizing agent, an antineoplastic agent and a prodrug.It can also be used (in the form of the hydrochloride salt)in combination with blue light illumination for the treatment of minimally to moderately thick actinic keratosis of the face or scalp.

2'-Deoxycytidine is one of the major nucleosides of DNA consisting of cytosine and deoxyribose and inhibits the biological effects of bromodeoxyuridine (Brdu). The nucleoside consists only of a pentose sugar attached to a purine or pyrimidine base and has no phosphate group. When N1 is attached to C1 of deoxyribose, deoxyribosides and nucleotides are formed from cytosine and deoxyribose; deoxycytidine monophosphate (dCMP), deoxycytidine diphosphate (dCDP), and deoxycytidine triphosphate (dCTP). cTP is the source of cytosine in RNA (ribonucleic acid) and deoxycytidine triphosphate (dCTP) is the source of deoxycytidine in DNA (deoxyribonucleic acid). Itaconic acid is a polymer.