Headache, fatigue, nausea, anxiety, poor concentration, or next-day impairment after cannabis may have several causes. They can reflect intoxication that has not fully resolved, a delayed edible, dehydration, sleep disruption, interaction with alcohol or medicines, recurrent vomiting associated with heavy use, or a different medical problem.
Do not assume every symptom is a harmless “weed hangover.”
What to do now
- Stop taking cannabis, CBD, alcohol, and other intoxicants.
- Do not drive, ride, swim alone, or operate equipment.
- Rest somewhere safe, ideally with a sober person nearby.
- Drink fluids normally if you are awake and not vomiting; do not force excessive water.
- Keep the exact product label and note what was taken, how much, when, and what else was used.
- For poisoning advice in Thailand, call the Ramathibodi Poison Center at 1367, available 24/7.
Do not take more cannabis to “balance” the effects. Internet remedies such as peppercorns, lemon, sugar, caffeine, or supplements are not substitutes for medical assessment.
When to get urgent help
Call Thailand emergency medical services at 1669 for chest pain, breathing difficulty, collapse, seizure, inability to wake, severe confusion, dangerous behaviour, weakness on one side, or severe or persistent vomiting. Seek help sooner for a child, pregnancy, an older adult, significant heart disease, or possible exposure to an unknown or synthetic product.
If symptoms are not improving or you are unsure what was taken, contact the poison centre or a clinician.
Why edibles deserve extra caution
The CDC cannabis-poisoning guidance notes that edible effects may take 30 minutes to 2 hours to appear, may last longer than expected, and can be unpredictable. Taking more before the first serving has fully taken effect increases poisoning and injury risk.
Keep all cannabis products locked, in their original child-resistant packaging, and away from children and pets.
Repeated symptoms
Repeated next-day impairment, needing more cannabis for the same effect, difficulty cutting down, withdrawal symptoms, or recurrent bouts of severe vomiting are reasons to stop and speak with a qualified clinician. Budtenders cannot diagnose these problems or prescribe a safer dose.
FAQ
Is a cannabis hangover always harmless?
No. Mild after-effects can occur, but serious symptoms, interactions, poisoning, or another medical condition may look similar.
Should I use CBD to counter THC?
Do not rely on a retail CBD product as an antidote. Product composition varies, CBD can interact with medicines, and urgent symptoms need professional help.
Can I drive the next morning?
Not if you feel impaired, drowsy, dizzy, slowed, or unfocused. Effects can last longer than expected, especially after edibles.
Who can I call in Thailand?
Ramathibodi Poison Center: 1367, 24/7. Emergency medical services: 1669.
