Cannabis safety depends on four factors

Dose, product type, route, and the person using it. THC causes impairment. CBD does not cause a high at common doses. Both can interact with prescription drugs. Start low and wait before adding more.

Cannabis Responsible Use Guide: Safe Buying Basics

Dose

Many state labels set one serving at 10 mg THC. A first-time user often starts at 1 mg to 2.5 mg. A 10 mg dose can cause anxiety, fast heart rate, and nausea in people with no tolerance. Wait at least 2 hours before taking more. Tolerance drops after a break of a few days. A dose that felt mild last month can feel strong today.

Safe Cannabis Consumption Instructions

Route changes onset and duration

  • Inhaled smoke or vape: effects in seconds to 10 minutes. Peak at 15 to 30 minutes. Duration 2 to 3 hours.
  • Oral edibles: effects in 30 to 120 minutes. Peak at 2 to 3 hours. Duration 4 to 6 hours. Some people report effects past 8 hours.
  • Tinctures held under the tongue: effects in 15 to 45 minutes.
  • Topicals: little to no psychoactive effect. Skin absorbs small amounts of THC.

Edible overdose is a common call to US poison centers. The delay in onset causes repeat dosing.

safe cannabis consumption instructions

Driving

THC slows reaction time and affects lane control. Impairment lasts 3 to 5 hours after smoked THC and longer after edibles. Blood THC levels do not track impairment. State law varies. Do not drive after use.

responsible cannabis use advice

Drug interactions

CBD and THC use liver enzymes in the CYP450 family, the same enzymes that clear many drugs. FDA notes CBD can raise levels of warfarin and clobazam and carries a liver injury warning. Alcohol adds sedation. Opioids plus cannabis raise breathing risk. Tell a pharmacist about every cannabis product you take.

Groups at higher risk

  • Under 25: THC affects brain development. Regular use raises risk of anxiety and psychosis in people with a family history.
  • Pregnancy and breastfeeding: CDC advises against use. THC passes to the fetus and into breast milk.
  • Heart or lung disease: smoke irritates airways. THC raises heart rate for 1 to 2 hours.
  • Older adults: dizziness, falls, and interactions with blood thinners.

Vaping and smoking

Smoke contains tar and carbon monoxide. Vitamin E acetate in some unregulated vape carts caused lung injury, known as EVALI. No safe level of smoke inhalation is established.

Vomiting syndrome

Daily high-THC use can cause cannabinoid hyperemesis syndrome. Symptoms are repeated vomiting, stomach pain, and relief from hot showers. Symptoms stop in most people after they quit.

Storage and label checks

Keep products in child-resistant packaging, locked, and out of sight. Edibles look like candy. US poison centers handle thousands of child exposures each year. Check the label for THC mg per serving, batch number, and a lab test result. Hemp-derived delta-8 and delta-10 products are not all lab tested.

Call for help

Call 911 for chest pain, trouble breathing, seizures, or a person who cannot be woken. Call Poison Control at 1-800-222-1222 for an edible overdose. Most THC overdoses are not fatal, but panic, vomiting, and fast heart rate need care.