Hi, Thanks for posting in HCM. I understand your concern. THC (tetrahydrocannabinol) is the chemical responsible for most of marijuana s psychological effects. When smoked or ingested, THC and other cannabinoids in marijuana attach to two types of receptors on cells in your body affecting the cells. THC remains in the blood has a half-life of about nineteen hours. Its metabolites, primarily 11-hydroxy-delta-9-THC, formed in the liver has a half-life of fifty hours. After one week, 25 to 30 percent of the THC and its metabolites might still remain in the body. Complete elimination of a large dose of THC and its metabolites might take two or three weeks. Methamphetamine is a strong central nervous system stimulant that is mainly used as a recreational drug. The half-life of methamphetamine is variable with a range of 5–30 hours. Its metabolites can be detected in urine and indicates its use within 1-4 days, but could be up to a week following heavy chronic use. It is advisable not to use such compounds during pregnancy and strictly avoid them as it could cause adverse effects to both mother as well as growing fetus. Hope the information provided would be helpful. All the best.