This may depend on several factors. This can include your body weight, metabolism, how often you use it, and the dosage. THC can be detected in the urine for up to 30 days for regular users. Meanwhile, it can remain for 3 to 4 days but it's best to contact your healthcare provider with more questions. Your hydration levels, the amount of exercise you do, and your diet can also determine how long THC remains in your system.