Supplement analysis backed by scientific evidence · PT

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Limited evidenceJoints & skin

Cucumber Extract (Q-Actin)

A concentrated cucumber extract sold for joint pain. Two small randomized trials report benefit, but both come from the ingredient's own research group, and no independent replication exists.

Evidence last reviewed: August 2026

What the science says

  • Osteoarthritis pain and function Limited evidence

    A 180-day multicentre randomized trial in 122 people with moderate knee osteoarthritis compared 10 mg twice daily of cucumber extract against glucosamine plus chondroitin and reported greater improvement in pain and function scores. There was no placebo arm, and the study was sponsored by the ingredient developer.

  • Mild to moderate joint pain in general Limited evidence

    A more recent randomized, double-blind, placebo-controlled study in adults with mild to moderate joint pain reported improvements in pain and stiffness over 30 days. It was small, short and published in a low-tier journal, so the result needs independent confirmation.

Dosage & safety

Studied dose10 mg twice daily of the standardized extract was used in both trials, taken with food.
SafetyWell tolerated in the reported trials, with no serious adverse events. Long-term safety is unknown. People allergic to cucurbitaceae (cucumber, melon, squash) should avoid it; not studied in pregnancy or breastfeeding.

Scientific references

Where to buy

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