TABLE 1.

HP monotherapy comparative studies.

HP intervention	Comparator	Study design	Sample size (n)	Follow-up duration	Main efficacy findings	Comparative interpretation	References
Harpadol® 2,610 mg/day (harpagoside 57 mg)	Diacerein 100 mg/day	RCT	122	16 weeks	Both groups demonstrated reductions in pain and Lequesne Index scores; lower rescue diclofenac use observed in the HP group	Symptomatic improvement appeared comparable under study conditions; long-term comparative efficacy remains uncertain	Chantre et al. (2000)
Doloteffin® 2,400 mg/day (harpagoside 60 mg)	Rofecoxib 12.5 mg/day	RCT, DB	88	6 weeks	Pain reduction and HAQ improvement reported in both groups; higher proportion of pain-free patients in the HP group	Some outcomes favored HP; however, direct equivalence with NSAIDs cannot be established because of limited sample size and study duration	Chrubasik et al. (2003)
Teltonal® 960 mg/day	Meloxicam 15 mg/day	RCT, AC	60	8 weeks	Similar reductions in VAS and WOMAC scores were observed between groups	No significant between-group difference was reported; interpretation limited by small sample size	Farpour et al. (2021)
HP extract 6,000 mg/day (harpagoside 50 mg)	Placebo	RCT, DB, PC	109	4 weeks	Increased proportion of pain-free patients and improvement in Arhus Index compared with placebo	Findings suggest short-term symptomatic benefit versus placebo	Chrubasik et al. (1996)

Abbreviations: VAS, visual analogue scale; WOMAC, Western ontario and mcMaster universities osteoarthritis index; RCT, randomized controlled trial; DB, Double-blind; AC, Active-controlled; PC, Placebo-controlled; HP, harpagophytum procumbens; MCID, minimal clinically important difference.