Side effects of cranberry tablets vary from person to person. However, the most common side effects include an upset stomach, nausea, vomiting and diarrhea, states Drugs.com.
Those taking cranberry in any form should seek emergency help if they show any signs of an allergic reaction, which includes hives, difficulty breathing and swelling of the face, lips, tongue or throat, advises Drugs.com. Less common symptoms such as pain or burning upon urination, vomiting, or severe stomach pain also warrant immediate discontinuation and an immediate call to a health care provider. Patients should also contact their health care provider for any possible signs of a kidney stone, such as painful or difficult urination, pink or red urine, nausea, vomiting, or waves of sharp pain in the side or back that reach the lower stomach and groin.
Cranberry tablets treat multiple conditions, including urinary tract infections, odor caused by incontinence and kidney stones, according to Drugs.com. This herbal product works by blocking bacteria from attaching to the bladder wall. People who are allergic to any ingredient in the supplement should not use cranberry tablets.