Can You Overdose on CBD Oil? Side Effects and When to Get Help
No fatal CBD-only overdose appears in the sources we reviewed, but high doses can strain the liver, and THC products pose real risks to kids and pets.
- Evidence
- Moderate
- Sources
- 10 linked
- Sponsored
- No ✓
- Checked
- Nov 2026
We found no reports of a fatal overdose from CBD alone, but too much can cause sleepiness, diarrhea, and liver enzyme rises. THC-containing products pose bigger risks, especially to kids.
We found no reports of a fatal overdose caused by CBD alone in the government and peer-reviewed sources we reviewed, but taking too much can still cause real side effects. High doses in clinical trials were linked to sleepiness, diarrhea, and raised liver enzymes. The more serious danger comes from CBD products that contain THC, especially when children or pets eat them by accident.
- A 2017 research review reported that doses of up to 1,500 mg of CBD a day have repeatedly been well tolerated in human studies.
- “Well tolerated” does not mean harmless. In Epidiolex trials, liver enzyme rises were dose-related and much more common at higher doses.
- Common side effects of too much CBD include sleepiness, diarrhea, decreased appetite, and fatigue.
- Products with hidden or added THC can cause intoxication. Poison centers reported a sharp rise in young children eating cannabis edibles between 2017 and 2021.
- For a possible poisoning, call Poison Help at 1-800-222-1222. Call 911 if someone has collapsed, had a seizure, has trouble breathing, or cannot be woken up.
Is there a lethal dose of CBD?
CBD (cannabidiol) is a cannabinoid, a natural compound from the cannabis plant that does not cause a high.
A 2017 review in Cannabis and Cannabinoid Research by Iffland and Grotenhermen concluded that CBD’s safety profile in humans is generally favorable. It stated that chronic use and high doses of up to 1,500 mg per day have repeatedly been shown to be well tolerated. The prescription CBD drug Epidiolex was also tested in a study where adult volunteers received single doses as high as 4,500 mg.
We did not find any reported human death from CBD alone in the FDA, NIH, or peer-reviewed sources we opened for this article. That said, the same review pointed out that important safety questions still have not been studied, and that larger, longer trials are lacking. “No known fatal overdose” is not the same as “no risk.”
What happens if you take too much CBD?
The best data on high doses come from Epidiolex, the only FDA-approved CBD medicine. It is a prescription drug for seizures linked to Lennox-Gastaut syndrome, Dravet syndrome, and tuberous sclerosis complex. Its trials used doses based on body weight, and its prescribing information lists these as the most common side effects:
- Sleepiness (somnolence) and sedation
- Decreased appetite
- Diarrhea
- Raised liver enzymes (transaminase elevations)
- Fatigue, weakness, and feeling unwell
- Rash, trouble sleeping, and infections
These were seen in patients with serious seizure conditions, often taking other seizure medicines. The FDA and NCCIH (the NIH center that studies complementary health products) also list sleepiness, decreased appetite, diarrhea, mood changes, and liver injury among CBD’s possible side effects.
How do higher doses affect the liver?
Liver effects are the main concern with large amounts of CBD. The FDA states that CBD can cause liver injury. The Epidiolex label shows how strongly this depends on dose.
| Situation (Epidiolex trials) | Share with ALT more than 3 times normal |
|---|---|
| 10 mg/kg/day | 1% |
| 20 mg/kg/day | 17% |
| 25 mg/kg/day (tuberous sclerosis complex) | 12% |
| Above 25 mg/kg/day (tuberous sclerosis complex study) | 25% |
| Taking valproate and clobazam as well (LGS/DS) | 30% |
| Taking neither valproate nor clobazam (LGS/DS) | 3% |
ALT is a liver enzyme that doctors measure in blood tests; higher levels can signal liver stress. Because of this risk, the label tells doctors to check liver blood tests before starting Epidiolex.
Healthy people are not immune. A 2025 review by a German Research Foundation food safety commission, published in Nutrients, reported raised liver enzymes in healthy volunteers taking 4.3 mg of CBD per kilogram of body weight per day for three to four weeks. Lower doses were not tested, so a safe threshold could not be set. The commission noted that some marketed oils could reach that level, for example 30 drops of an oil containing 20% CBD.
Tip: Concentration matters more than drop count. A few drops of a strong oil can contain far more CBD than many drops of a weak one. Our CBD dosage calculator and guide on how many drops of CBD oil to take show how to work out the milligrams.
Can you overdose on hemp oil?
“Hemp oil” is a loose label, and the name alone does not tell you how much CBD, or THC, a bottle contains. The overdose question depends on what is actually in the bottle, so check the label and the certificate of analysis (COA), a lab report from an independent testing lab listing cannabinoid amounts. Our article on hemp oil vs CBD oil explains the difference.
Why is THC the bigger overdose risk?
Many CBD products are not THC-free. THC (delta-9-tetrahydrocannabinol) is the cannabinoid that causes a high, and too much can cause strong intoxication. A 2017 JAMA study of 84 CBD products bought online found THC in about 21% of them, and only about 31% were accurately labeled for CBD. The FDA has also said it is investigating CBD products with unsafe levels of contaminants, including THC.
Children. NCCIH notes there have been many reports of children unintentionally consuming cannabis products, sometimes needing emergency care or hospitalization. A 2023 Pediatrics study of national poison center data found 7,043 reported edible cannabis exposures in children under 6 from 2017 to 2021. Cases rose from 207 in 2017 to 3,054 in 2021, most happened at home, and 22.7% of children were admitted to the hospital. These were cannabis edibles in general, not only CBD products.
Pets. The FDA cautions pet owners against using cannabis products and says accidental ingestion in animals is well documented in scientific literature. It lists signs such as lethargy, vomiting, and tremors.
Important: Store all CBD and cannabis products, especially gummies and other edibles, locked up and out of reach of children and pets. The FDA advises that if a child may have eaten a cannabis product, you should take the child to a doctor or emergency department, especially if the child acts unusually or seems ill.
Can CBD be dangerous with other medicines or alcohol?
Yes, and this can matter more than the dose. The FDA warns that CBD can affect how other drugs work, potentially causing serious side effects, and that combining CBD with alcohol or other drugs that slow brain activity increases the risk of sleepiness and injuries. The Epidiolex label notes that seizure medicines like valproate and clobazam raised the rate of liver enzyme increases.
If you take any prescription medicine, ask your doctor or pharmacist before using CBD. The FDA has also said it has concerns about cannabis use during pregnancy and breastfeeding; see our article on CBD and pregnancy.
When should you get help?
- Call 911 for an emergency. If the person has collapsed, had a seizure, has trouble breathing, or cannot be woken up, call 911 right away.
- Call Poison Help for advice. Dial 1-800-222-1222. It is free, confidential, and available 24 hours a day, 7 days a week, and connects you to your local poison center.
- Have the product ready. Keep the package or label nearby so you can say what was taken, how much, and when.
- For pets, call a vet. The FDA advises contacting a veterinarian, an animal emergency hospital, or an animal poison control center right away.
- Watch for warning signs later. Seek medical care for signs that could point to liver problems, and report side effects to the FDA through MedWatch.
Frequently asked questions
How much CBD is too much?
There is no established safe upper limit for over-the-counter CBD. Studies show side effects and liver enzyme changes become more likely as doses rise. Ask a doctor about your situation.
Can CBD overdose kill you?
We found no reports of a fatal overdose from CBD alone in the sources we reviewed. Risks come mainly from side effects, drug interactions, and products that contain THC.
What does taking too much CBD feel like?
Reported effects include sleepiness, tiredness, diarrhea, and reduced appetite. Read more in does CBD make you tired.
My child ate a CBD gummy. What should I do?
Call Poison Help at 1-800-222-1222, or 911 if your child is very drowsy, has trouble breathing, or has a seizure. Many gummies contain THC, which can cause serious effects in children.
Is it dangerous if my dog ate CBD oil?
Contact a veterinarian or animal poison control center right away. The FDA lists lethargy, vomiting, and tremors as possible signs in pets.
Sources
- Cannabis and Cannabinoid Research (Iffland & Grotenhermen, 2017) — An Update on Safety and Side Effects of Cannabidiol
- DailyMed (NIH) — Epidiolex (cannabidiol) oral solution prescribing information
- U.S. FDA — What You Need to Know About Products Containing Cannabis or Cannabis-Derived Compounds, Including CBD
- U.S. FDA — FDA Regulation of Cannabis and Cannabis-Derived Products, Including CBD: Q&A
- NCCIH — Cannabis (Marijuana) and Cannabinoids: What You Need To Know
- Nutrients (2025) — Cannabidiol in Foods and Food Supplements: Evaluation of Health Risks and Health Claims
- Pediatrics (Tweet et al., 2023) — Pediatric Edible Cannabis Exposures and Acute Toxicity: 2017–2021
- JAMA (Bonn-Miller et al., 2017) — Labeling Accuracy of Cannabidiol Extracts Sold Online
- America’s Poison Centers — Get Poison Help
- PoisonHelp.org — Poison Help line and when to call 911
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