The hooked fruit of devil's claw (Harpagophytum procumbens), held in a hand

Strong evidence19 studies

How we rate

“Strong” = several concordant meta-analyses or systematic reviews. “Moderate” = one synthesis, or several controlled trials. “Limited” = early trials only. The rating is about the quality of the studies, not about how useful the supplement is.

Harpagophytum (devil's claw)

African root for pain: one placebo-controlled trial on back pain and two versus medication, based on medium-quality evidence at best; no clear effect in meta-analysis on osteoarthritis, and a risk to the stomach.

Joints

Benefits

Back pain: in 197 patients experiencing a flare-up of chronic lower back pain, 4 weeks of extract left more patients free of pain and rescue medication: 10 with 100 mg of harpagoside per day, 6 with 50 mg, 3 on placebo.
Compared to rofecoxib: in 88 patients with a back pain flare-up, 6 weeks of extract (60 mg of harpagoside) yielded 10 pain-free patients versus 5 on 12.5 mg of rofecoxib, a non-significant difference in this pilot trial.
Hip and knee osteoarthritis: in 122 patients, 2,610 mg of powder per day for 4 months relieved pain and discomfort as much as 100 mg of diacerein, with fewer painkillers and anti-inflammatory drugs taken in addition.
Better tolerated than diacerein: in the same trial, 8.1% of diarrhea with harpagophytum versus 26.7% with diacerein.
Cochrane review of back pain: across 14 trials (2,050 participants), harpagophytum appears to reduce pain more than placebo, but with medium-quality evidence at best.
According to a systematic review of 12 trials, strong evidence for an aqueous extract at 50 mg of harpagoside per day in chronic lower back pain flare-ups, and moderate evidence for a powder at 60 mg in osteoarthritis.
Studies without a control group: in 75 osteoarthritis patients, 12 weeks of aqueous extract reduced the WOMAC index by 22.9%; in 259 rheumatism patients, 60% reduced or stopped their painkillers within 8 weeks.

Precautions

Stomach: cases of gastrointestinal bleeding have been reported, and a review advises avoiding it; in trials, adverse effects are mainly stomach pain and digestive disorders, in about 3% of patients. If you have an ulcer or stomach ache, talk to your doctor. Diarrhea: 8.1% of patients taking powder in the osteoarthritis trial. Long term: no data on long-term toxicity, and trial doses are at the low end of the range; the authors call for more safety data. Limitations: osteoarthritis: a meta-analysis finds no difference with the control group for harpagophytum (a single trial), on low-quality evidence. A review of 35 plant trials notes favorable results for several harpagophytum-based products, but judges that no plant has proven its efficacy beyond a doubt. Recommendation against: an expert committee for US special forces advises against its use for chronic muscle and joint pain. Quality of trials: out of 8 placebo-controlled trials, 6 lack transparency; no available product has fully satisfactory evidence. Not a replacement for anti-inflammatory drugs: a 2026 review concludes this, with small trials, heterogeneous products and doses, and short follow-ups. Placebo effect: a review judges that it has no established efficacy beyond the placebo effect.

Recommended dosage

An extract providing 50 to 100 mg of harpagoside per day (600 to 2,400 mg of extract depending on the product), or 2,610 mg of powder per day.

How to take it

Target audience: trials involve adults with chronic back pain experiencing a flare-up or hip or knee osteoarthritis; none involve athletes.
Dose: count in harpagoside, not in milligrams of plant; results are better with at least 50 mg of harpagoside per day than with products providing less.
Product: the results of one product do not apply to another, according to the analysis of 20 studies.
Duration: 4 weeks in the placebo-controlled trial on the back, 6 weeks versus rofecoxib, up to 4 months in osteoarthritis.
Dosage administration: 480 mg of extract twice a day in an open-label study of 130 patients; 6 capsules of powder per day in the osteoarthritis trial.
What it does not do: in healthy volunteers, 21 days of powder did not modify any of the inflammatory molecules targeted by anti-inflammatory drugs.

Did you know?

In volunteers who took 2 g per day for 21 days, devil's claw did not modify any of the inflammatory molecules (prostaglandins, thromboxane, leukotriene) acted upon by conventional anti-inflammatory drugs.

What the studies say

This systematic review and meta-analysis evaluated the efficacy and safety of oral herbal medicines for osteoarthritis, including Harpagophytum procumbens. One randomized clinical trial on Harpagophytum showed no difference compared to the control group. The study concludes that evidence is insufficient to support the effective and safe use of these herbal medicines due to the low quality of the evidence.
Del Grossi Moura M, Lopes LC, Biavatti MW, Kennedy SA, de Oliveira E Silva MC, Silva MT, de Cássia Bergamaschi C. — Phytotherapy research : PTR (2017) — View the source study

For information only: not a substitute for medical advice. Dietary supplements are not a replacement for a varied, balanced diet. Learn more