A urine test can detect THC for up to 30 days after use. THC is detectable in blood for the shortest time, up to 12 hours, but can stay longer in heavy users. Hair tests show THC use for the longest ...

By Priyanjana Pramanik, MSc. By translating cannabis use into standardized THC units, researchers uncover clear weekly ...

How much cannabis is too much? A new study proposes a weekly THC limit linked to addiction risk, suggesting adults staying ...

Many states in the U.S. have legalized cannabis either medically or recreationally, but without legalization at the federal level regulation is left to states, including testing for contaminants and ...