1- Department of Health Policy Management and Evaluation, University of Toronto, Faculty of Medicine, Toronto, Canada.

Harpgophytum procumbens for osteoarthritis and low back pain: a systematic review.

BMC Complement Altern Med. 2004 Sep 15;4:13. 


2- Laboratoires Arkopharma, Carros, France.

Efficacy and tolerance of Harpagophytum procumbens versus diacerhein in treatment of osteoarthritis.

Phytomedicine. 2000 Jun;7(3):177-83. 


3- Department of Forensic Medicine, University of Freiburg, Germany, herbal Medicines Research and Education Centre, university of Sydney, NSW, Australia and  Department of Anaesthesia, University of Bristol, Bristol Royal Infirmary, UK.

A randomized double‐blind pilot study comparing Doloteffin® and Vioxx® in the treatment of low back pain.

Oxford Journals Medicine & Health  Rheumatology 2003 Volume 42,  Issue 141-148.


4- Department of Forensic Medicine, University of Freiburg, Albertstr. 9, 79104 Freiburg, Germany.

A 1-year follow-up after a pilot study with Doloteffin for low back pain.

Phytomedicine. 2005 Jan;12(1-2):1-9.


5- Department of Medical Biometry, University of Heidelberg, Germany.

Effectiveness of Harpagophytum extract WS 1531 in the treatment of exacerbation of low back pain: a randomized, placebo-controlled, double-blind study.

Eur J Anaesthesiol. 1999 Feb;16(2):118-29.


6- School of Health Sciences, Queen Margaret University, Edinburgh EH12 8TS, Scotland.

Effectiveness and safety of Devil's Claw tablets in patients with general rheumatic disorders.

Phytother Res. 2007 Dec;21(12):1228-33


7- Department of Psychiatry and Psychotherapy, University of Freiburg Medical School, Germany.

Inhibition of TNF-alpha synthesis in LPS-stimulated primary human monocytes by Harpagophytum extract SteiHap 69.

Phytomedicine. 2001 Jan;8(1):28-30.