Table 11.

RCTs conducted between 1980 and 2017.

DJD	RCT 39	400 mg Harpagophytum extract (not specified), and 25 mg diclofenac, or placebo 3× daily for 6 months. Overall confirmation of anti-inflammatory effects without side effects.	~1980	Chaouat, cited in [66,67]
DJD	RCT 50 (25/25)	Harpagophytum extract (<30 mg harpagoside/day) and phenybutazone (300 mg per day for the first four days, then 200 mg) respectively, for 28 days. Devil’s claw found equally effective to phenybutazone.	1980	Schrüffler [533]
DJD	RCT 50 (25/25)	Patients treated with Harpagophytum extract (<20 mg harpagoside/day) or placebo for three weeks showed a significant decrease in pain severity vs. placebo.	1984	Guyader [534]
DJD	RCT 100 (50/50)	Patients treated with Harpagophytum extract (60 mg harpagoside/day) or placebo for 30 days. Only 6 patients in the verum group still experienced moderate pain vs. 32 in the placebo group.	1990	Pinget and Lecomte [535]
DJD	RCT 89 (45/44)	Patients treated with Harpagophytum extract (60 mg harpagoside/day) or placebo for two months. Significant decrease in severity of pain and significant increase in spinal and cofexomoral mobility vs. placebo.	1992	Lecomte and Costa [536]
MSD	RCT 118 (59,59)	Patients treated with Harpagophytum extract (50 mg harpagoside/day) or placebo for 4 weeks. Treatment group used less analgesics, had greater improvement in median Arhus scores (20% vs. 8%; p < 0.059), and had more patients pain-free at the end (9/51 vs. 1/54; p = 0.008).	1996	Chrubasik et al. [537,538,539]
MSD	RCT 109 (54/55)	Patients treated with Harpagophytum extract (50 mg harpagoside/day) or placebo for 4 weeks. Rescue medication: tramadol. Significant improvement in Arhus index and pain index, and co-medication reduced vs. placebo.	1997	Chrubasik et al. [540]
DJD	RCT 100 (50/50)	Patients treated with Harpagophytum extract (30 mg harpagoside/day) or placebo for 30 days. Favorable effects were evident after 10 days vs. placebo.	1997	Schmelz and Hämmerle [541]
MSD	RCT 197 (65/66/66)	Patients treated with Harpagophytum extract (50 mg (1), 100 mg (2) harpagoside/day) or placebo (3) for four weeks. 6, 10, and 3 patients were pain-free in groups 1, 2 and 3, respectively. Arhus index score decreased but not statistically significant. Dose-related effect not confirmed.	1999	Chrubasik et al. [542]
DJD	RCT 122 (62/60)	Patients treated with Harpagophytum extract (57 mg harpagoside/day) or diacerhein at 100 mg daily for four months. Results showed significant improvement in both groups at a similar rate.	2000	Chantre et al. [543,544]
MSD	RCT 63 (31/32)	Patients treated with Harpagophytum extract (~30 mg harpagoside/day) or placebo for 4 weeks. Significant efficacy for visual analogue scale, pressure algometer test, muscle stiffness test, and muscular ischemia test. No differences to placebo in anti-nociceptive muscular reflexes or electromyogram activity.	2000	Göbel et al. [512,513,545,546]
DJD	RCT 46 (24/22)	Patients treated with ibuprofen (800 mg) and Harpagophytum extract (~30 mg harpagoside/day) or placebo for 20 weeks. WOMAC scores decreased similarly, but during an ibuprofen-free period, symptoms worsened less than 20% for 71% of devil’s claw patients vs. 41% of placebo patients.	2001	Frerick et al. [547]
DJD	RCT 78 (39/39)	Patients treated with Harpagophytum extract (~30 mg harpagoside/day) or placebo for 20 weeks. Co-medication ibuprofen. Symptoms improved similarly for both groups.	2002	Biller [548]
MSD	RCT 88 (44/44)	Patients treated with Harpagophytum extract (60 mg harpagoside/day) for 6 weeks or 12.5 mg/day of rofecoxib. Outcome scores improved similarly for both groups. Follow-up confirmed the results of the pilot study.	2003	Chrubasik et al. [538,539,549,550,551,552]
MSD	RCT 97 (36/31/30)	Patients treated with Harpagophytum extract (~30 mg harpagoside/day) or NSAID (Voltaren 150 mg or Vioxx 12.5 mg), duration not provided; outcomes show equality of treatment.	2005	Lienert et al. [553,554]
DJD	RCT 60 (30/30)	Patients treated with combination of Harpagophytum and Apium graveolens extract (cream, 1.5 cm, twice daily) or placebo for 2 weeks. Treatment group showed significant improvement in algometer, flexion, and extension readings.	2006	Pillay [555]
Sore throat after tracheal intubation	RCT 60 (30/30)	Patients treated with Harpagophytum extract (480 mg one hour before intubation) or placebo plus premedication (fentanyl, midazolam, propofol). No significant difference was observed between groups.	2016	Anvari et al. [556]
DJD	RCT 92 (46/46)	Patients treated with combination of Rosa canina, Urtica sp., Harpagophytum procumbens, and vitamin D (20.0 g puree and 4.0 g juice concentrate, 160 mg dry extract, 108 mg dry extract, 5 µg, respectively) or placebo for 12 weeks. WOMAC and quality of life scores significantly improved vs. placebo.	2017	Moré et al. [557]

DJD = degenerative joint diseases (osteoarthritis); MSD = musculo-skeletal disorders (low back pain); RCT = randomized controlled trial; NSAID = non-steroidal anti-inflammatory drug; WOMAC = Western Ontario and McMaster Universities.