Effect of an oral complementary medicine combination for symptomatic knee osteoarthritis: A double-blind, randomized, placebo-controlled trial

Many individuals use complementary medicine therapies for osteoarthritis, despite limited scientific supporting evidence. These therapies have demonstrated anti-inflammatory, antioxidative, and chondroprotective effects via different molecular pathways, suggesting potential therapeutic benefits. This trial aimed to evaluate the efficacy and safety of a novel oral complementary medicine combination in adults with symptomatic knee osteoarthritis at 12 weeks. The 12-week, double-blind, randomized, placebo-controlled ATLAS trial was conducted in Australia from July 2024 to April 2025 (ACTRN12623000380695). Eligible participants were aged ≥40 years with symptomatic knee osteoarthritis and radiographic Kellgren-Lawrence grade ≥2. Participants were randomized 1:1 to receive the complementary medicine combination, comprising a total daily dose of Boswellia serrata extract 250 mg, pine bark extract 100 mg, methylsulfonylmethane 1500 mg, curcumin 500 mg, and piperine 5 mg, or placebo. The primary outcome was the 12-week change in knee pain (0-100 mm visual analogue scale (VAS)). A 95% confidence interval excluding differences >18 mm between groups was interpreted as the absence of a clinically meaningful difference. Harms were monitored weekly. Eighty-four participants were recruited (mean [SD], age 63.7 [8.0] years, BMI 29.0 [5.5] kg/m), and 57% were female. At 12-weeks, both groups (intention-to-treat population: complementary medicine, n=42; placebo, n=41) showed a decrease in VAS pain (least squares means: complementary medicine 20.1 mm vs placebo 20.3 mm), however with no difference between groups: 0.16 mm (95% CI -6.81 to 7.12). The safety profile of experiencing any AE was similar between groups (risk difference, -3.4% [95% CI -24.8-17.9%]); and most adverse events were mild or moderate. Four participants experienced serious adverse events, unrelated to the treatment. The complementary medicine combination was not superior to placebo for improving pain over 12 weeks, and the evidence does not support the use of this combination to treat people with symptomatic knee osteoarthritis.