Glucosamine, chondroitin sulfate, and the two in combination for painful knee osteoarthritis

Clegg DO, Reda DJ, Harris CL, et al. · The New England Journal of Medicine

Neither glucosamine, chondroitin, nor the combination beat placebo on the primary endpoint (20% WOMAC pain reduction: 60.1% placebo vs 64-66.6% supplement arms, ns). An exploratory subgroup with moderate-to-severe pain responded better to the combination (79.2% vs 54.3%, p=0.002).

Population

US adults with symptomatic knee osteoarthritis (GAIT trial)

Intervention

Glucosamine HCl 1500 mg/day, chondroitin sulfate 1200 mg/day, or both, for 24 weeks; celecoxib 200 mg/day as active comparator

Comparator

Placebo

Limitations

Overall null; the often-quoted combination benefit is a post-hoc subgroup with small n. Used glucosamine hydrochloride, not the sulfate salt used in positive European trials. High placebo response (60%).