Effectiveness and safety of glucosamine and chondroitin for the treatment of osteoarthritis: A meta-analysis of randomized controlled trials 

A meta-analysis of randomized controlled trials published in the Journal of Orthopaedics Surgery and Research in 2018 assessed the symptomatic effectiveness and safety of oral symptomatic slow-acting drugs (SYSADOAs) on the treatment of knee and/or hip osteoarthritis, such as chondroitin, glucosamine, and combination treatment with chondroitin plus glucosamine. Twenty-six articles describing 30 trials met the inclusion criteria and were included in the meta-analysis.   

References:

Zhu X, Sang L, Wu D, Rong J, Jiang L. Effectiveness and safety of glucosamine and chondroitin for the treatment of osteoarthritis: a meta-analysis of randomized controlled trials. J Orthop Surg Res. 2018;13(1):170. Published 2018 Jul 6. doi:10.1186/s13018-018-0871-5 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6035477/