Over 20 million people in the USA alone suffer from chronic kidney disease - and many are not even aware they have it! An additional 20 million others are at increased risk, as per the USA National Kidney Foundation.  However, finding safe and effective herbs for promoting kidney health however may seem quite challenging. Whereas many herbs for liver and colon health have been studied, conclusive studies on herbs for kidney maintenance remain somewhat scarce in the Western world. 
While research on herbs for the kidneys is somewhat limited, the National Kidney Foundation consents there are some herbs that can indeed promote kidney health when used in sensible amounts.  Here are 10 herbs and natural remedies that have been studied and which are thought beneficial for the kidneys:
10 Herbs For Kidneys
The young, "unfermented" leaves of the tea plant (Camellia sinensis) are widely considered to have the best nutritional qualities. Most green teas are unfermented or very lightly fermented, as opposed to oolong teas which are semi-fermented and black teas which are fully fermented.
Tea has been shown to possess anti-inflammatory, astringent and diuretic properties. It also contains compounds called polyphenols that have been known to inhibit kidney stones and even prevent certain cancers.  It is these polyphenols that are widely investigated for their anti-oxidant activities to prevent diseases caused by oxidative stress like kidney related disorders. As one recent Japanese study has shown, the biological activities and low toxicity of polyphenols have beneficial effects on pathological states related to oxidative stress renal disease. 
Couch Grass (Elymus repens)
Rich in polysaccharides, volatile oils, mucilages and other nutrients, couch grass has been traditionally used to increase urine production and in treating urinary tract infections like cystitis and urethritis. Because it has diuretic, demulcent and antibacterial properties, couch grass is also used to partially dissolve kidney stones.  Consequently, researchers in Italy discovered that when combined with potassium citrate, dry extract of couch grass significantly reduced total number of stones, size of urinary stones and uric acid urinary excretion among the treated group after a 5 month follow up period in a randomized controlled study. 
Rehmannia is a herb that is less well known in the West but has been used in Traditional Chinese Medicine since ancient times. The steamed roots of rehmannia have been widely used a kidney tonic against various renal diseases. A 2009 study showed that this herb possesses reno-protective effects in progressive renal failure by reducing serum creatinine level, 24-h urinary protein excretion and glomerulosclerosis.  Phytosterols, antioxidants, along with iridoid glycosides are reported to be responsible for rehmannia's therapeutic benefits on the kidneys. 
An ornamental plant indigenous to Australia, India and tropical countries in Southeast Asia, banaba has been used since ancient times as a natural diuretic and as a remedy for kidney and bladder problems.  While much research is focused on the herb's high levels of corosolic acid and how this may improve blood sugar levels among type II diabetics, the leaves of banaba have also been used to relieve urinary tract infections. Evidence also suggests regular intake of banaba leaf tea can alleviate discomfort associated with kidney stones and help prevent gallbladder stones. 
Java Tea (Orthosiphon stamineus)
Listed in French, Indonesian, Dutch and Swiss pharmacopoeias as a remedy for kidney ailments, java tea has diuretic properties and increases the kidney's ability to eliminate nitrogen-containing compounds. Some experts believe java tea is effective against kidney stones, kidney infections and in promoting renal function because of the flavones, glycoside, volatile oil and potassium it contains.  Aside from these, recent studies of java tea reveal caffeic acid and rosmarinic contents which have antioxidant properties and trigger helpful biological mechanisms that support its use in folk medicine. 
Initially thought to be beneficial in treating urinary tract infections, recent scientific studies revealed that cranberries may also contribute in preventing the formation of kidney stones. Research shows that cranberries are good sources of quinic acid, a very acidic substance which the body cannot dissolve so it remains unchanged until it is excreted as urine. This substance helps in making the urine acidic thereby preventing the phosphate and calcium ions to form as kidney stones.
When made into tea, dandelion makes an effective herb for the liver and the kidneys. In addition to its diuretic properties, dandelion is an excellent source of nutrients like zinc, potassium, iron, and Vitamins A, C, D and B-Complex. The roots of dandelion contain active ingredients that help dissolve kidney stones. They continue to attack kidney stones until they break up and pass. 
For more than 2000 years, ginger has been widely used to treat different types of health illnesses including renal disorders. Scientific experimental evidences point that ginger contains active constituents that activate the antioxidant pathways resulting to increased renal protection. 
A good reservoir of valuable dietary elements like Vitamin C, folic acid, Vitamin B3, iron, calcium and protein, ginger is a wonderful herb that also aids in dissolving kidney stones. More than its ability to cleanse the kidneys, ginger can also be used to dissolve kidney stones.
According to research, cucumber is a vegetable consist of 97% water. When made into juice or taken raw, cucumbers are excellent sources of valuable nutrients like Vitamin A, Vitamin C, lutein, beta carotene, calcium, magnesium, protein, phosphorus and calcium. 
Noted for their diuretic and laxative properties, intake of cucumber is highly recommended to people suffering kidney problems. This vegetable helps in eliminating harmful toxins out of kidneys as well as in dissolving bladder and kidney stones. 
Research shows that onions can really be helpful in eliminating pain associated with kidney stones. Regular intake of onion juice is thought to be useful in making the kidney stones pass within at least 24 hours. 
 Use of Herbal Supplements in Chronic Kidney Disease. http://www.kidney.org/atoz/content/herbalsupp.cfm
 Green Tea Polyphenols for the Protection against Renal Damage Caused by Oxidative Stress. http://www.ncbi.nlm.nih.gov/pubmed/22844338
 Effects of the association of potassium citrate and agropyrum repens in renal stone treatment: results of a prospective randomized comparison with potassium citrate. http://www.ncbi.nlm.nih.gov/pubmed/?term=couch+grass%2C+kidney
 Rehmannia glutinosa ameliorates the progressive renal failure induced by 5/6 nephrectomy. http://www.ncbi.nlm.nih.gov/pubmed/19146934
 Evaluation of the genotoxicity of Orthosiphon stamineus aqueous extract. http://www.ncbi.nlm.nih.gov/pubmed/21044879