The leaves of the cleavers plant ( Galium aparine) have small hooked hairs that cause it to “cleave” to the fingers when touched, hence the name. The whole leaf has been used as a flavoring in soups and stews. Roasted seeds are used as a coffee substitute. The leaves and flowers are used medicinally. Cleavers is primarily used for urinary problems and fluid retention, on the basis of its apparent diuretic (urine-stimulating) effects. It has also been recommended for enlarged lymph nodes, tonsillitis, hepatitis, and snake bites.
Cleavers is often included in herbal mixtures offered for the treatment of kidney and bladder problems, including bladder infections, kidney stones, and prostatitis. It is also said to help “cleanse” the lymph system. However, there has not been any meaningful scientific evaluation of the herb. Even animal and test-tube studies are essentially lacking.
A typical recommended dose of cleavers is one cup of tea three times daily, made by steeping 10–15 grams of the herb in a cup of hot water.
Cleavers has not undergone any meaningful safety testing. Safety in young children, pregnant or nursing women, or people with severe liver or kidney disease has not been established.
In case cleavers does in fact have diuretic effects as claimed, people taking the medication lithium should use cleavers only under the supervision of a physician, as dehydration can be dangerous with this medication.1
If you are taking lithium, do not use cleavers except under the supervision of a physician.