← All supplements
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.

Where to buy

View on iHerb

Ships to 180+ countries · welcome discount for new customers

Referral link — this site may earn a commission on purchases.

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.

How to take it

TimingTwice daily, morning and evening, as in both trials.
With food?Take it with food, which is how it was dosed in the studies.
Worth knowingSkip it if you react to cucumber, melon, courgette or squash — they are all cucurbits and cross-reactivity is common.

Frequently asked questions

Does cucumber extract (Q-Actin) work for knee osteoarthritis?

The evidence is limited: a 180-day trial in 122 people with knee osteoarthritis reported greater improvement with cucumber extract than with glucosamine plus chondroitin. There was no placebo arm, the developer sponsored it, and no independent replication exists.

How much cucumber extract should I take for joints?

Both cucumber extract trials used 10 mg of the standardised extract twice daily, morning and evening, with food.

Is Q-Actin better than glucosamine and chondroitin?

One developer-sponsored trial reported better pain and function scores with cucumber extract than with glucosamine plus chondroitin. Without a placebo group or independent confirmation, that comparison is limited evidence.

Who should avoid cucumber extract?

Avoid cucumber extract if you are allergic to cucumber, melon, courgette or squash, since they are all cucurbits and cross-reactivity is common. It was well tolerated in trials, but long-term safety and use in pregnancy are unstudied.

Scientific references

Related in Joints & skin

Herbal medicines: what the evidence says (335)