BACKGROUND: Results of an exploratory trial suggested activity trends of Zingiber officinale-Tinopsora cordifolia (platform combination)-based formulations in the treatment of osteoarthritis (OA) Knees. These formulations were "platform combination+Withania somnifera+Tribulus terrestris" (formulation B) and "platform combination+Emblica officinale" (formulation C). This paper reports safety of these formulations when used in higher doses (1.5-2 times) along with Sallaki Guggul and Bhallataka Parpati (a Semecarpus anacardium preparation). MATERIALS AND METHODS: Ninety-two patients with symptomatic OA knees were enrolled in a 6 weeks investigator blind, randomized parallel efficacy 4-arm multicenter drug trial. The 4 arms were (I) formulation B, 2 t.i.d.; (II) formulation B, 2 q.i.d.; (III) platform combination+Sallaki Guggul; (IV) Bhallataka Parpati+formulation C. A detailed enquiry was carried out for adverse events (AE) and drug toxicity as per a priori check list and volunteered information. Laboratory evaluation included detailed hematology and metabolic parameters. Patients were examined at baseline, first and fourth weeks, and on completion. Standard statistical program (SPSS version 12.5) was used for analysis. RESULTS: None of the patients reported serious AE or withdrew due to any drug-related toxicity. Mild gut-related (mostly epigastric burning) AE was reported. A mild increase in liver enzymes [serum glutamic pyruvate transaminase (SGPT), serum glutamic oxaloacetic transaminase (SGOT)] without any other hepatic abnormality was reported in 2 patients (group IV). Other laboratory parameters remained normal. The mean improvement in active pain visual analog scale (1.4, CI 0.5-2.22), WOMAC (functional activity questionnaire) pain score (1.37, CI 0.22-2.5), and urinary C-TAX (cartilage collagen breakdown product) assay was maximum (NS) in group IV. Lower dose group I showed numerically superior improvement compared with higher dose group II. CONCLUSION: The results suggested that despite higher doses, standardized Ayurvedic formulations demonstrated a good safety profile. An improved efficacy and likely chondroprotective effect was shown by group IV intervention. A confirmatory drug trial with adequate power and sample size was planned based on the learning from this trial.