CBD, effects of

CBD, effects of n. phr. What cannabidiol has been shown to do in people. The FDA has accepted one effect: in the prescription medicine Epidiolex, CBD reduces seizures in three rare conditions. No other use has passed FDA review.

This entry is general information, not medical advice. Ask a doctor or pharmacist before you take CBD, above all if you take other medicines.

Checked against FDA and NIH pages on Oct. 4, 2026.

Notes

What has the FDA approved CBD for?

One product, Epidiolex, a purified CBD taken by mouth on prescription. The FDA first approved it in 2018. Today it is approved to treat seizures linked to:

1. Lennox-Gastaut syndrome;
2. Dravet syndrome;
3. tuberous sclerosis complex;

in patients aged 1 year and older (FDA). These are rare, severe forms of epilepsy. Epidiolex is prescribed and dosed by a doctor; it is not sold over the counter.

What about everything else CBD is sold for?

No CBD product other than Epidiolex has been evaluated by the FDA for whether it works or is safe for any condition. The FDA has warned companies against selling CBD with claims that it prevents, treats or cures serious diseases such as cancer, Alzheimer’s disease, psychiatric disorders and diabetes (FDA consumer update).

In January 2023 the FDA said it had not found adequate evidence to decide how much CBD can be consumed, and for how long, before it causes harm (FDA, Jan. 26, 2023). This glossary does not repeat claims that have not passed that review, and it gives no doses.

What side effects are known?

From the FDA and the NIH (FDA consumer update; NCCIH):

Effect	What the source says
Liver	CBD can cause liver injury
Other medicines	CBD can change how other drugs work, which may cause serious side effects
Alcohol and sedatives	Taken together they raise the risk of drowsiness and the injuries it can lead to
Alertness	Changes in alertness, most often drowsiness
Digestion	Diarrhea and decreased appetite
Mood	Changes in mood
Male fertility	Harm to fertility in males, or in the male offspring of exposed females, has been reported

The FDA also names groups it is most concerned about: children, and people who are pregnant (FDA, Jan. 26, 2023).

Is an over-the-counter CBD product the same as Epidiolex?

No. Epidiolex is made and tested as a drug, with a fixed dose in each millilitre. Over-the-counter CBD products may contain more or less CBD than the label says, and may contain THC (NCCIH). When researchers tested 84 CBD extracts sold online, 26 matched their label within 10 percent and 18 contained THC (Bonn-Miller and others, JAMA, 2017). The full spectrum entry explains the label words.

Why can’t CBD be sold as a supplement or added to food?

Because it is the active ingredient of an approved drug, the FDA excludes CBD from the dietary supplement definition and bars adding it to food sold across state lines (FDA). In 2023 the agency said neither its food nor its supplement rules can manage CBD’s risks, and that Congress would need to create a new path (FDA, Jan. 26, 2023).

The shop on this site

The shop sells hemp THCA flower. It is not CBD flower and it is not a CBD product, and we make no health claim for it. Our menu today is high-THCA hemp flower, not CBD flower. Smoked, it gets you high and shows up on THC drug tests.

Sources

• U.S. Food and Drug Administration. FDA Regulation of Cannabis and Cannabis-Derived Products, Including Cannabidiol (CBD). Page dated July 16, 2024.
• U.S. Food and Drug Administration. What You Need to Know (And What We’re Working to Find Out) About Products Containing Cannabis or Cannabis-derived Compounds, Including CBD. Consumer update, March 5, 2020.
• U.S. Food and Drug Administration. FDA Concludes that Existing Regulatory Frameworks for Foods and Supplements are Not Appropriate for Cannabidiol, Will Work with Congress on a New Way Forward. Jan. 26, 2023.
• NIH, National Center for Complementary and Integrative Health. Cannabis (Marijuana) and Cannabinoids: What You Need To Know.
• Bonn-Miller MO and others. “Labeling accuracy of cannabidiol extracts sold online.” JAMA 318 (2017): 1708–1709. doi.org/10.1001/jama.2017.11909

Questions

What does CBD do?

In FDA-reviewed trials, a purified CBD medicine, Epidiolex, reduced seizures in Lennox-Gastaut syndrome, Dravet syndrome and tuberous sclerosis complex. That is the only use the FDA has found to be safe and effective.

What is CBD used for?

As a prescription drug, for seizures in those three rare conditions. People buy over-the-counter CBD for many other reasons, but no other CBD product has been through FDA review for any use.

What is CBD good for?

The evidence the FDA accepts covers one thing: seizures in three rare conditions, treated with Epidiolex. For any other purpose the FDA says there is not enough evidence about how much CBD is safe, or for how long.

Can CBD interact with other medicines?

Yes. The FDA says CBD can change how other drugs work and can cause serious side effects that way. Tell your doctor or pharmacist if you take it.

What are the side effects of CBD?

The FDA lists liver injury, interactions with other drugs, drowsiness that is worse with alcohol or sedatives, diarrhea, decreased appetite and changes in alertness. Harm to male fertility has also been reported.