Does CBD Make You Tired? Why CBD Oil Can Cause Drowsiness

Yes, CBD can make some people tired. Sleepiness is one of the most commonly reported side effects of CBD, and it shows up on the FDA-approved label for the prescription CBD drug Epidiolex. It tends to be more likely at higher doses, when CBD is combined with alcohol or sedating medicines, and when a product also contains THC. If CBD oil makes you tired, a few practical changes may help, and some situations call for a talk with your doctor.

Is tiredness a known side effect of CBD?

CBD (cannabidiol) is a cannabinoid, a natural compound from the cannabis plant. It does not cause a high, but it is not without effects. The FDA states that CBD can cause changes in alertness, most commonly sleepiness, and that this should improve when CBD is stopped or the amount is reduced. NCCIH, the NIH center that studies complementary health products, lists decreased alertness and sleepiness among CBD’s possible side effects too.

NCCIH also notes that side effects seen in Epidiolex studies, such as sleepiness, appear to be due to CBD itself rather than contaminants. In other words, drowsiness is not just a sign of a poor-quality product.

A 2017 review of CBD safety research reached a similar conclusion: tiredness was among the most commonly reported side effects in clinical studies, along with diarrhea and changes in appetite or weight.

How common is sleepiness with CBD?

The clearest numbers come from Epidiolex, the only FDA-approved CBD medicine. It is a prescription drug for seizures linked to Lennox-Gastaut syndrome (LGS), Dravet syndrome (DS), and tuberous sclerosis complex (TSC). Its prescribing information reports these rates of sleepiness and sedation, including lethargy:

Keep in mind these were patients with serious seizure disorders, many on other medicines, taking doses based on body weight. Over-the-counter CBD users usually take much less, and their experience may differ. Still, the label shows two useful patterns: sleepiness was more common at the higher dose, and much more common when CBD was combined with clobazam, a sedating seizure medicine.

The label also says these effects were more common early in treatment and may lessen with continued use.

Why does CBD oil make me tired?

Researchers have not pinned down exactly why CBD makes some people drowsy. But several practical factors can make tiredness more likely:

• Dose. In Epidiolex trials, sleepiness was generally dose-related. Strong oils can deliver more CBD per drop than you might expect.
• Food. Taking CBD with food can greatly increase how much you absorb. The Epidiolex label reports that a high-fat meal raised peak levels about 5-fold compared with an empty stomach.
• Alcohol. Alcohol both adds its own sedation and raised CBD exposure in the Epidiolex label, increasing peak levels by 93%.
• Other medicines. CBD can change how other drugs work, and other drugs can change how CBD works, according to the FDA.
• THC. Many CBD products, especially full-spectrum ones (extracts that keep other plant compounds, including small amounts of THC), contain THC. A 2017 JAMA study found THC in about 21% of 84 CBD products bought online.

Our explainer on CBD isolate covers products made to contain CBD alone, and does CBD get you high explains how CBD and THC differ.

Is it safe to drive after taking CBD?

Be careful until you know how CBD affects you. The Epidiolex label tells patients not to drive or operate machinery until they have enough experience with the drug to know whether it affects their ability to do so.

Some research is reassuring for CBD on its own. In a 2020 randomized trial in JAMA, 26 healthy occasional cannabis users vaporized CBD-dominant, THC-dominant, mixed, or placebo cannabis before on-road driving tests. CBD-dominant cannabis did not significantly impair lane control compared with placebo, while THC-dominant and mixed cannabis did, in the first test after use.

That study used a single 13.75 mg inhaled dose in young healthy adults. It does not tell you how you will respond to an oral product, a higher dose, a product with THC, or CBD combined with alcohol or medicines. If you feel drowsy, do not drive.

What can you do if CBD makes you tired?

If drowsiness is bothering you, these steps may help. They are general tips, not medical advice for any condition.

1. Check the milligrams. Work out how much CBD you are actually taking per serving. Our CBD dosage calculator can help, and our guide to how many drops of CBD oil to take explains concentration.
2. Consider using less. The FDA says sleepiness should improve when CBD is reduced or stopped.
3. Change the timing. If you feel drowsy, avoid taking CBD before driving, work, or other tasks that need full alertness.
4. Be consistent with food. Since meals can greatly change absorption, taking CBD the same way each time makes effects more predictable.
5. Skip alcohol and check your medicines. Avoid combining CBD with alcohol, and ask a pharmacist about interactions with anything you take.
6. Read the COA. A certificate of analysis (COA) is an independent lab report. Check total THC for your batch.

Can CBD help you sleep?

Many people hope it will, but the evidence is thin. NCCIH states that the effects of cannabis and cannabinoids on sleep problems in people without other illnesses are uncertain. It also notes that where people with other conditions reported better sleep, it is uncertain whether the products affected sleep directly.

A 2025 review by a German Research Foundation food safety commission, published in Nutrients, found no scientific evidence supporting sleep or relaxation claims for CBD at the lower doses typical of food and supplement products. Interestingly, the Epidiolex label lists insomnia and poor-quality sleep among common side effects as well, so CBD does not affect everyone the same way.

Feeling drowsy is not the same as getting better sleep. If you have ongoing sleep problems, talk to a healthcare provider.

Frequently asked questions

Sources

• 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
• NCCIH — Cannabis (Marijuana) and Cannabinoids: What You Need To Know
• Cannabis and Cannabinoid Research (Iffland & Grotenhermen, 2017) — An Update on Safety and Side Effects of Cannabidiol
• JAMA (Arkell et al., 2020) — Effect of Cannabidiol and THC on Driving Performance: A Randomized Clinical Trial
• JAMA (Bonn-Miller et al., 2017) — Labeling Accuracy of Cannabidiol Extracts Sold Online
• Nutrients (2025) — Cannabidiol in Foods and Food Supplements: Evaluation of Health Risks and Health Claims