The test is based on a chemical reaction from the sample, similar to how home pregnancy tests work. If the chemicals detect drugs, a certain reaction will be noted on the test. Marijuana, cocaine, ecstasy, speed, heroin and other drugs, including those that fall into the barbiturate category. Ritalin has also been shown to cause a false positive under this category of drug. Certain pain medications, whether they are name brand or generics containing Codeine, can produce false positive results for the use of heroin or morphine, which fall under the opiate category.
Many pharmacies currently stock home drug tests.
This depends on the brand and where you make the purchase. Many Internet sites sell home drug tests at a reduced cost, but when you factor in shipping charges, you may not see a large savings compared to store bought tests. It's best to shop around and compare prices and brand names. The first step is to confront your teen. Charging after your teen screaming and hollering will only put them in a defensive mindset, and you can almost be guaranteed you will not get any answers to your questions.