Cyanobacteria are essential for the vast number of compounds they produce and the possible applications in the pharmaceutical, cosmetical, and food industries. As Lyngbya species’ characterization is limited in the literature, we characterize this cyanobacterium’s growth and biomass. L. purpureum was grown and analyzed under different salinities, culture media, and incubation times to determine the best conditions that favor its cell growth and the general production of proteins, carbohydrates, lipids, and some pigments as phycocyanin and chlorophyll a. In this study, each analyzed biomolecule’s highest content was proteins 431.69 mg g−1, carbohydrates 301.45 mg g−1, lipids 131.5 mg g−1, chlorophyll a 4.09 mg g−1, and phycocyanin 40.4 mg g−1. These results can provide a general context of the possible uses that can be given to biomass and give an opening to investigate possible biocompounds or bio metabolites that can be obtained from it.