Start with a low dose. Wait. Do not mix with alcohol or sedatives. Do not drive. Buy lab-tested products. Store away from children and pets. For inhaled cannabis, take one inhalation. For edibles, start with 2.5 mg THC. Wait 2 hours before adding more. The effect can last 8 hours.

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Dose

Dose depends on THC content, body weight, tolerance, and route. A common starting dose for edibles is 2.5 mg THC. Some US states set a standard serving at 5 mg or 10 mg THC. CBD doses range from 10 mg to 100 mg per day in studies. No standard CBD dose exists. Start at the low end. Increase by 2.5 mg every 2 days.

safe cannabis use guidelines

Onset and duration by route

  • Inhalation: onset 10 seconds to 10 minutes. Peak 10 to 30 minutes. Duration 1 to 3 hours.
  • Edibles: onset 30 to 120 minutes. Peak 2 to 4 hours. Duration 4 to 8 hours.
  • Tinctures under the tongue: onset 15 to 45 minutes. Duration 2 to 6 hours.
  • Topicals: no psychoactive effect. Onset 15 to 30 minutes for local relief.

Inhalation steps

  1. Use a clean device. Set a vaporizer to 315 to 450 F.
  2. Take one small inhalation. Hold 2 to 5 seconds.
  3. Exhale. Wait 10 minutes.
  4. Repeat one inhalation if needed. Stop at 4 inhalations.

Avoid combustion above 600 F. Avoid deep holds. Deep holds do not increase effect. They irritate the lungs.

Cannabis Use Safety Guide: Doses, Interactions, and Risks

Edible steps

  1. Read the label. Find the THC mg per piece.
  2. Cut the piece. Start with 2.5 mg THC.
  3. Eat with food. Wait 2 hours.
  4. Do not take more within 2 hours. Keep a log of dose and time.

Drug interactions

Cannabis interacts with CYP450 enzymes. It can raise levels of warfarin, clobazam, and other drugs. CBD can raise levels of some anticonvulsants. Avoid alcohol, opioids, benzodiazepines, and antihistamines. These add sedation. Talk to a pharmacist before use.

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Groups to avoid

  • People under 21.
  • Pregnant or breastfeeding people.
  • People with a history of psychosis.
  • People with heart disease or liver disease.
  • People taking sedatives.

Product selection

Buy lab-tested products. Look for a Certificate of Analysis (COA). Check for pesticides, heavy metals, residual solvents, and microbials. Check THC content. Hemp CBD must have less than 0.3% THC by dry weight under US law. State-legal cannabis may have higher THC.

Storage and child safety

Store in a locked container. Keep in original packaging. Keep away from children and pets. Edibles can look like candy. Call Poison Control at 1-800-222-1222 if a child eats cannabis. US poison centers reported more than 3,000 cases in 2021 for children under 6.

Driving and work

Do not drive for 4 to 6 hours after inhaled cannabis. Do not drive after edibles until the next day. Effects can last 8 hours. Impairment can last longer. No reliable roadside test for impairment exists. Police use field sobriety tests.

When to call for help

Call 911 for chest pain, severe confusion, seizures, or trouble breathing. For anxiety or rapid heartbeat, sit down, drink water, and wait. The effect will pass. Do not take more.