Hello:I am a professional manufacturer of chondroitin sulfate and chondroitin sulfate health care product. The quality and lasting period is long and good.About our chondroitin sulfate we have many kinds .origin form bovine ,porcine,chicken,shark.The assay:85% ,90%,95%.As a professional manufacture of chondroitin sulfate  for almost 11 years.We guratten that all our products are made in 100% qualified materials with competitive prices.If you are interest in it ,I am gald to introduce more details to you ,please feel free to contact me