Side Effects: What to Expect
THC side effects include short-term memory impairment, anxiety (especially at high doses), dry mouth, red eyes, increased heart rate, and impaired coordination. CBD has a milder profile: possible drowsiness at high doses, mild GI upset, and potential interaction with certain medications (particularly blood thinners). For anxiety-prone individuals, high-THC products can worsen symptoms.
Medical Evidence Base
THC has strong evidence for chemotherapy-induced nausea (FDA-approved synthetic variants: dronabinol, nabilone), chronic pain, and spasticity in MS. CBD has FDA approval for Dravet syndrome and Lennox-Gastaut syndrome (Epidiolex), with growing evidence for social anxiety disorder, PTSD, and inflammatory conditions.
Drug Interactions
CBD inhibits CYP450 liver enzymes, affecting how your body metabolizes certain medications including warfarin, some antiepileptics, and specific antidepressants. THC can potentiate sedatives and alcohol. If you are on prescription medication, consult your doctor before starting either cannabinoid.
Tolerance and Dependence
THC users can develop tolerance requiring higher doses over time. Dependence is possible in heavy daily users (roughly 9% lifetime rate), with mild withdrawal symptoms upon cessation. CBD does not produce psychoactive tolerance or dependence. Taking regular breaks resets THC sensitivity within 2 to 4 weeks.
Quick-Reference Comparison Table
| Factor | THC | CBD |
|---|---|---|
| Anxiety Risk | High at doses above 15mg | Low, may reduce anxiety |
| Tolerance Buildup | Yes, weeks to months | Minimal |
| Dependence Risk | 9% lifetime (heavy use) | Not established |
| Drug Interactions | Alcohol, sedatives | Blood thinners, antiepileptics |
| FDA Approval | Synthetic THC (nabilone) | Epidiolex (CBD for epilepsy) |
| Drug Test Risk | High (detectable 3 to 30 days) | Low (trace amounts) |