Science, Tech, Math › Science Marijuana Facts Share Flipboard Email Print This is a close-up photo of a cannabis (marijuana) bud. Ryan Bushby Science Chemistry Medical Chemistry Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate by Anne Marie Helmenstine, Ph.D. Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. Updated January 27, 2019 Marijuana is one of the names given to the Cannabis sativa plant when it is used as a drug. The active ingredient in marijuana is tetrahydrocannabinol or THC. What does marijuana look like? The appearance of marijuana depends on how it will be used, but it often resembles tobacco. Higher quality marijuana is made using only the flowering buds of the plant, while other marijuana may include leaves, stems, and seeds. Marijuana may be green, brown, or grayish in color. How is marijuana used? Marijuana may be smoked as a cigarette, in a pipe, in a blunt, or using a vaporizer. It may be consumed as a tea or in food. Why do people use marijuana? Marijuana is used because of its primary active ingredient, tetrahydrocannabinol (THC), produces a relaxed state and may heighten the senses. What are the effects of marijuana use? The effects of smoking marijuana are felt as soon as the THC enters the bloodstream and last from 1-3 hours. Absorption of THC is slower if marijuana is ingested, typically producing effects 30 minutes to an hour after exposure and lasting up to 4 hours. Marijuana increases the heart rate, relaxes and enlarges bronchial passages, and dilates the blood vessels in the eyes, which may cause them to appear bloodshot. THC causes dopamine release, which produces euphoria. Colors and sounds may seem more intense, time may appear to pass more slowly, and pleasant sensations may be experienced. Dry mouth is common, as are intense thirst and hunger. After the euphoria passes, a user may feel sleepy or depressed. Some users experience anxiety or panic. What are the risks associated with marijuana use? Smoking marijuana results in many of the same risks associated with smoking tobacco, including coughing, increased susceptibility to lung infections, airway obstruction, and probably an increased risk of developing lung cancer. Other methods of taking marijuana are not associated with respiratory damage. Even low doses of marijuana impair concentration and coordination. Long-term heavy marijuana use may impair short-term memory long after the drug has been metabolized. Street Names for Marijuana Grass Pot Weed Bud Mary Jane Dope Indo Hydro 420 Acapulco Gold BC Bud Buddha Cheeba Chronic Ganja Green Goddess Herb Homegrown KGB (Killer Green Bud) Kindbud Locoweed Shake Sinsemilla Skunk Wacky Tabacky Continue Reading