People have different metabolic rates, which is a major determining factor as to how long THC and CBD remain in the system. Each person is different, so there is no definitive answer to this question. Generally, the THC in edibles is detectable in urine for up to 30 days, in saliva for 1-3 days and in blood for 3-4 days. Other major determining factors are the frequency of use and the potency of the gummies you consume.