Chondroitin sulfate is sourced from natural products, with high variability in terms of chain length and sulfation pattern. The variability in chondroitin sulfate composition extends to its origin, making it possible to differentiate between chondroitin sulfate from terrestrial and marine sources. One way to look at this difference is in terms of the proportion of disaccharide units: chondroitin sulfate from terrestrial animals is almost exclusively composed of non-sulfated (O) and monosulfated (A and C) units, while in marine species the proportion of disulfated (D, E and B) units is higher. Furthermore, marine chondroitin sulfate chains tend to be longer, with molecular weight of up to 70 kDa in chondroitin sulfate from shark, while in terrestrial animals molecular weight is typically below 45 kDa.