Plain English Summary
Background and study aims
Harpagophytum Procumbens (commonly known as devil’s claw) is a plant that originates from southern Africa. It’s roots are used to reduce pain and fever. The chemicals thought to be responsible for the plants pain killing properties are Harpagoside, Harpagide and Procumbide. This study is testing the pain relieving properties of a cream containing Harpagophytum Procumbens in people suffering from knee pain caused by osteoarthritis.
Who can participate?
Adults suffering from osteoarthritis of the knee.
What does the study involve?
Participants are randomly allocated to one of two groups. Those in group 1 are given a harpagophytum containing cream to apply to their knee. Those in group 2 are given a placebo cream that looks and feels like the harpagophytum containing cream to apply to their knee. All participants assess for themselves the amount of pain they are feeling before and after they have put on the cream.
What are the possible benefits and risks of participating?
There are no risks to participating in this study as the ingredients of the cream are absolutely free of any possible adverse effects.
Where is the study run from?
A number of orthopedic private practices in Thessaloniki and Volos (Greece)
When is the study starting and how long is it expected to run for?
February 2016 to August 2016
Who is funding the study?
Synapse Hellenic Pharmaceuticals & Services
Who is the main contact?
Dr Eleftherios Teperikidis
The effectiveness of harpagophytum procumbens cream in the relief of osteoarthritic pain of the knee: a double blind, placebo controlled, randomised interventional study
The hypothesis of the study is that harpagophytum Procumbens cream is better than placebo in the relief of osteoarthritic knee pain.
Not provided at time of registration
Double blind, placebo controlled, randomised interventional study
Primary study design
Secondary study design
Randomised controlled trial
Patient information sheet
Not available in web format, please use contact details to request a participant information sheet
Osteoarthritis of the knee
Patients who meet the radiographic inclusion criteria will be asked to initially evaluate the level of their pain in the knee on a Visual Analogue Scale (0 – 10). Based on the V.A.S scale result and the level of osteoarthritis it is decided by the researcher whether the inclusion criteria are met. All patients will be asked to sign a patient release form before participating in the trial. Patients will then be randomly assigned to either treatment or placebo group.
In the treatment group, 3 mL of a harpagophytum containing cream will be applied on the affected knee. The placebo group will receive 3 mL of a cream that has been designed to have the same color, smell and texture as the active cream.
Ten minutes after the application of the cream, patients will be asked to evaluate the level of the pain that they feel on a Visual Analogue Scale (0 – 10), as well as if they experience any adverse effect (skin reaction etc.). Through the ten minute waiting period, the researcher will complete the The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), an established and accredited questionnaire used in high quality clinical trials, evaluating the problems caused by Osteoarthritis in patient’s every day life.
At the end of the study all researchers will fill out a questionnaire regarding the execution of the trial as per the instructions given.
Primary outcome measure
Patient improvement on pain as evaluated by a Visual Analogue Scale (0-10) ten minutes after application of the cream.
Secondary outcome measures
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Osteoarthritis Stage (Kellgren & Lawrence Scale) 2 - 3
2. Patient’s Knee - Pain Self Evaluation (VAS 0 - 10) 4, 5, 6, 7
Target number of participants
Participant exclusion criteria
1. Osteoarthritis Stage (Kellgren & Lawrence Scale) 0, 1, 4
2. Patient’s Knee- Pain Self Evaluation (VAS 0 - 10) 0 – 3 , 8 - 10
3. Use of analgesic or anti-inflammatory medications, topical or oral on the day of the study
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Number of orthopedic private practices
Thessaloniki and Volos
Synapse Hellenic Pharmaceuticals & Services
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Intention to publish date
Participant level data
Available on request
Basic results (scientific)