Know2eat

Devil’s claw

Harpagophytum procumbens

Herbs & Botanicals

What devil’s claw may help with

Ranked by how strong the human evidence is — best supported first.

Best supportedJoint comfortLimited evidence· 1 source

Then, in order

About Devil’s claw

The secondary root tuber of a southern African plant, standardised to the iridoid glycoside harpagoside. Sold as a tablet, capsule or aqueous extract.

Devil’s claw has a small European trial literature in low back pain and osteoarthritis, some of it comparing it against non-steroidal anti-inflammatories, with results that are modestly favourable but come from studies with real methodological limitations. Aqueous and ethanolic extracts contain different amounts of harpagoside and are not equivalent products.

Sold as
Standardised extract tablet, Capsule, Aqueous extract, Tincture, Tea
Standardised to
Commonly standardised to 1–3% harpagoside, or a stated milligram amount per dose — a product without this marker may not resemble what was studied.
Also known as
Grapple plant, Harpagophytum, Wood spider

Regulation: Registered in several European countries as a traditional herbal medicine for minor joint pain, a category based on long-standing use rather than demonstrated effect. Harpagophytum is subject to sustainability concerns and CITES monitoring in parts of its range.

What the research used

The amounts, forms and durations published trials of Devil’s claw actually administered.

These are the amounts published trials administered — not a recommendation, and not a dose to copy. Trial participants were screened, supervised and given a characterised preparation. What is in a retail bottle is frequently not what was studied, and the amount that suits one person is not general advice.

  • Studied for Low back pain and osteoarthritis

    50–100 mg

    Limited

    Standardised extract expressed as harpagoside, daily · 4–16 weeks

    Trials specify harpagoside content, but most retail labels state total extract weight instead, which can differ several-fold in what it delivers.

  • Studied for Whole powdered root

    2–5 g

    Limited

    Dried powdered root, divided doses · 4–12 weeks

    Powdered root doses come from older European trials and cannot be converted into extract doses.

This is general information about food, not medical advice. It cannot diagnose, treat or replace guidance from a clinician who knows your history.

When it was taken

Each window says whether a trial compared it against an alternative, or whether it is convention and pharmacology. Most timing advice is the second kind.

None of the timings below were directly compared in a trial. They reflect how the research happened to dose, or what the pharmacology implies — which is not the same as a timing being better.

  • With food

    Not enough

    Taken with food in most protocols because the bitter iridoids stimulate gastric acid secretion. This is tolerability practice, not a tested comparison.

    Timing was not directly compared. This reflects convention or how the compound behaves in the body, not a trial showing this window works better.

The evidence in depth

Best supported: Limited

What each association actually rests on, and the papers behind it. A rating describes the state of the research, not how promising the supplement sounds. How we rate evidence.

Joint comfort

Joint Health
Limited evidence

Some trials report reduced pain in low back pain and osteoarthritis over several weeks, occasionally comparable to a low dose of a non-steroidal anti-inflammatory. Reviewers rate the evidence as moderate quality at best, with few trials and limited long-term data.

What may be going on: Harpagoside inhibits inflammatory signalling pathways in cell models, though absorption and metabolism in people are not well described.

Limited evidence. Early human work, or mostly lab and animal research.

View the 1 source

Deep research mode adds each paper’s own conclusion and stated limitations.

Digestive comfort

Gut & Digestive Health
Not enough evidence

Traditional use as a digestive bitter has not been tested in controlled trials, so there is not enough evidence to say anything useful about it.

Not enough evidence. Not enough human research to say anything useful yet.

View the 1 source

Deep research mode adds each paper’s own conclusion and stated limitations.

Things to know

Interactions, contraindications and dose limits, most serious first. Concentrated extracts interact with medication in ways the whole plant does not, so this section carries more weight here than it does on a food page.

  • Avoid

    Peptic ulcer and reflux

    Devil’s claw increases gastric acid secretion and is contraindicated in active peptic ulcer disease, gastritis and significant reflux.

  • Interaction

    Warfarin and antiplatelet drugs

    Interacts withWarfarin, antiplatelet drugs, CYP2C9 substrates

    Case reports describe raised INR in people taking devil’s claw with warfarin, and laboratory work suggests effects on platelets and on CYP2C9 metabolism.

  • Interaction

    Heart rhythm and blood pressure medication

    Interacts withAntiarrhythmics, digoxin, antihypertensives

    Animal work reports effects on heart rate and conduction, so caution applies with antiarrhythmics, digoxin and blood pressure medication.

  • Avoid

    Pregnancy

    Devil’s claw has documented oxytocic activity and should not be used in pregnancy.

  • Worth knowing

    Gallstones and diabetes medication

    It stimulates bile flow, which matters with gallstones, and has been reported to lower blood glucose, which matters for anyone on glucose-lowering drugs.

Evidence ratings on this page: 1 limited evidence, 1 not enough evidence.

Supplements are sold in the US without pre-market review of efficacy or safety. Nothing on this page is a recommendation to take Devil’s claw, or a dose to follow.