Strains linked to headaches

Headache is not among the dozen common adverse events listed in the abstract of Whiting and colleagues' JAMA analysis of cannabinoid trials, where dizziness and dry mouth come first. Verdex shows the same gap: 27 of 74 published profiles list it, against 69 for dry mouth. Headband's summary describes a slow-building high felt as pressure around the head.

The best-documented link runs through stopping. The DSM-5-TR lists headache among the physical symptoms of cannabis withdrawal after heavy, prolonged use, and a January 2026 clinical review (Dhillon, Journal of Military, Veteran and Family Health) puts onset at 24 to 48 hours after stopping, with resolution within one to two weeks.

Reports also run the other way. In a Strainprint app dataset of 12,293 headache sessions (Cuttler et al., Journal of Pain, 2020), people rated headache nearly 50% lower after cannabis use, though tolerance appeared. Observational data like that cannot show cannabis caused or cured anything, but it explains why side-effect and treatment stories tangle. Dehydration and smoke are often suspected triggers, but the research reviewed for this page contains no trial that isolates either.

Headaches that are not about cannabis

The NHS says to call 999 or go to A&E if a headache:

• started suddenly and is extremely painful,
• comes with numbness or weakness in the body or face, or trouble speaking, balancing or remembering,
• comes with drowsiness, confusion, a seizure or loss of vision.

Also see dizzy, the more common complaint.