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Cannabidiol Side Effects

The most commonly reported side effects of cannabidiol include seizure, off label use, and hospitalisation, based on 22,328 FDA adverse event reports from 2014 to 2025. 6.0% of reports found the drug to be ineffective.

Cannabidiol side effects

Percentages show how often each reaction appears relative to total reports for cannabidiol.

1
Seizure26.0%5,802
2
Off Label Use9.9%2,205
3
Hospitalisation9.3%2,075
4
Product Use In Unapproved Indication8.0%1,793
5
Diarrhoea7.6%1,702
6
Drug Ineffective6.0%1,348
7
Somnolence5.6%1,245
8
Death5.4%1,206
9
Fatigue5.2%1,172
10
Product Dose Omission Issue5.0%1,124
11
Weight Decreased3.7%829
12
Weight Increased3.6%800
13
Vomiting3.2%716
14
Decreased Appetite3.1%689
15
Nausea2.9%652

These are voluntary reports and do not establish that cannabidiol caused these reactions.

Report severity

57.7%Serious12,876 reports
29.3%Hospitalizations6,541 reports
7.8%Fatal1,734 reports

Seriousness is determined by the reporter, not by OpenClaim.

Cannabidiol drug interactions

Other drugs that appear in adverse event reports alongside cannabidiol. Drugs flagged as a suspected cause appear in the first column. Drugs taken at the same time but not suspected appear in the second.

Also suspected

1
Clobazam3.9%866
2
Levetiracetam2.7%601
3
Fenfluramine2.4%542
4
Vigabatrin2.0%448
5
Stiripentol1.8%407
6
Lacosamide1.5%344
7
Valproic-acid1.4%319
8
Topiramate1.4%316
9
Lamotrigine1.2%257
10
Phenobarbital-sodium1.0%221
11
Perampanel0.9%209
12
Clonazepam0.9%191
13
Phenytoin0.8%189
14
Rituximab0.8%172
15
Cenobamate0.8%169

Taken alongside

1
Clobazam15.8%3,519
2
Levetiracetam10.6%2,371
3
Clonazepam7.1%1,596
4
Lamotrigine6.7%1,497
5
Diazepam6.6%1,479
6
Lacosamide6.2%1,394
7
Ergocalciferol5.7%1,272
8
Topiramate5.1%1,137
9
Acetaminophen4.9%1,098
10
Divalproex-sodium4.9%1,086
11
Albuterol3.7%835
12
Rufinamide3.7%826
13
Zonisamide3.6%798
14
Lorazepam3.2%713
15
Gabapentin2.9%643

Co-occurrence in adverse event reports does not establish a drug interaction. Patients often take multiple medications, and these lists reflect prescribing patterns rather than causal relationships. Consult a healthcare provider about potential drug interactions.

Who reports cannabidiol side effects

24.5% of cannabidiol adverse event reports involve female patients and 25.3% involve male patients. The largest age group is adult at 46%. These figures reflect who reports side effects, not underlying risk.

Sex

Female24.5%
Male25.3%
Unknown50.2%

Age group

< 23.7%
2–1127.2%
12–1713.5%
18–6445.9%
65+9.7%

What is cannabidiol used for

Conditions and purposes for which patients were taking cannabidiol when the adverse event was reported.

Abdominal PainAbnormal BehaviourAcute Disseminated EncephalomyelitisAffect LabilityAffective DisorderAicardi^s SyndromeAlcoholismAnalgesic TherapyAngelman^s SyndromeAnkylosing SpondylitisAntibody Test AbnormalAntiinflammatory TherapyAnxietyArthralgiaArthritis

Showing 15 of 454 indications

Cannabidiol brand names and reporting trend

Cannabidiol is sold under the brand name Epidiolex.

Brand names

Epidiolex4,522

Quarterly reports (20142025)

20142016202020242025

An upward trend reflects increased FAERS reporting overall, not necessarily increased risk.

Taking cannabidiol with another medication?

Ask OpenClaim about your specific drug combination. Get a sourced report using FDA data, drug labels, and medical literature.