There is no medical evidence that goldenseal root cleanses urine and bloodstreams, notes WebMD. Despite reports to the contrary, people who take goldenseal do not increase their chances of false-negative results for tests for marijuana, cocaine, amphetamines or other drugs.
Reputable medical studies have shown that drinking a gallon of water containing goldenseal does not have an effect on drug tests over that of drinking the water without the herb, states WebMD. People also take goldenseal for urinary tract infections, stomach ulcers, menstrual irregularities, upset stomach and colitis, though there is insufficient medical evidence to prove the herb has any effect on these conditions. Women who are pregnant or breastfeeding and children should not take goldenseal, as there is evidence of harmful effects, including brain damage.