Responsible use in one paragraph
Start with a low THC dose. Wait before adding more. Do not drive after use. Keep products locked away from children and pets. No use under age 21. No use during pregnancy or breastfeeding. Federal law classifies cannabis as a Schedule I substance, while many states allow adult use at 21 and older. State rules on possession limits, home grow, and public use differ. Buy from a licensed store, read the label, and log what you take.
What is Responsible Cannabis Use?
Dose
THC causes intoxication. CBD does not. A common starting dose for a new user is 2.5 mg of THC in an edible and one low-potency puff of smoked or vaped flower. A standard regulated edible serving is 10 mg. A 100 mg package holds 10 servings. A person with low tolerance may need one quarter of a serving. Divide the product with a knife or scale. Gummies, chocolates, and drinks are hard to split by eye.
Timing
- Inhaled (smoke or vape): effects in about 10 minutes, peak near 30 minutes, fade in 1 to 3 hours.
- Oral (edibles, capsules, drinks): effects in 30 to 120 minutes, peak near 2 to 4 hours, fade in 4 to 8 hours or more.
- Wait at least 2 hours before a second edible dose. Feeling nothing after 20 minutes is expected.
Product labels
Licensed stores sell products with test results for potency, pesticides, mold, and heavy metals. Labels list THC mg per serving, servings per package, batch number, and warnings. Concentrates such as wax, shatter, and oil hold 60% to 90% THC. Flower runs about 15% to 30% THC by weight. Higher potency raises the odds of anxiety, racing heart, and paranoia.
Driving
Cannabis slows reaction time, splits attention, and changes lane position. Impairment lasts several hours. All 50 states prohibit driving under the influence of cannabis. There is no standard roadside breath test for THC. Police use blood draws, field sobriety tests, and officer observation, and blood THC does not track impairment well. Use a rideshare or a sober driver. Alcohol plus cannabis raises impairment over either alone.
Mixing
Alcohol with cannabis raises heart rate, causes blood pressure to drop on standing, and brings nausea and vomiting. Opioids, benzodiazepines, and sleep drugs add sedation and raise overdose risk with opioids. Cannabis can change how the liver breaks down some medicines through the CYP450 system, including blood thinners and seizure drugs. Ask a pharmacist before combining.
Health risks
- Frequency: near-daily use raises the risk of cannabis use disorder. About 3 in 10 people who use cannabis have cannabis use disorder. About 1 in 10 adults who use become dependent, and about 1 in 6 who start as teens.
- Age: use before 18 can affect memory, attention, and learning.
- Mental health: heavy THC use links to paranoia, hallucinations, and psychosis in people with a personal or family history of psychosis or schizophrenia.
- Lungs: smoke carries tar, irritants, and carcinogens. It can raise coughing, wheezing, and bronchitis. Vaping carries a risk of EVALI, tied to vitamin E acetate in THC cartridges.
- Heart: cannabis raises heart rate and blood pressure for 1 to 2 hours. Case reports link use to heart attack and irregular heartbeat, with higher risk for people who have heart disease. The American Heart Association advises against use before or after a heart attack.
- Pregnancy: no safe amount. THC passes to the fetus and into breast milk and links to lower birth weight.
Steps that cut risk
- Buy from a licensed store, so test results exist.
- Keep a log: product, THC mg, time, food intake, effects.
- Lock storage. Gummies resemble candy, and child poisonings from edibles have risen.
- Do not share pipes or vapes. Saliva carries viruses.
- Take a 2 to 4 week break to check tolerance and dependence.
- Set limits: days per week, mg per day, and hours before work or driving.
Signs of a problem
Signs of cannabis use disorder: using more than planned, craving, failed attempts to stop, use despite problems at work, school, or home, and withdrawal (irritability, sleeplessness, appetite loss, headache) in the first week after stopping. SAMHSA runs the National Helpline at 1-800-662-HELP (4357), free and confidential, 24 hours a day, in English and Spanish.
Skip use and ask a doctor
- Pregnancy or breastfeeding
- Under 21, unless a pediatrician directs medical use
- Personal or family history of psychosis, schizophrenia, or bipolar disorder
- Heart disease, arrhythmia, or uncontrolled high blood pressure
- Use of opioids, benzodiazepines, sedatives, or blood thinners
- Driving or machine work within 6 to 8 hours