There is no single agreed-upon safe dose of CBD, and the answer has shifted significantly in recent years as more data has come in. The UK’s Food Standards Agency, which issued one of the few official daily limits, slashed its recommended intake from 70 mg per day down to just 10 mg per day in 2023, citing new evidence that long-term daily use above that level could contribute to liver problems over time. That 10 mg figure is far lower than what most CBD products on the market suggest, and it highlights a real gap between what people are taking and what regulators consider well-supported by safety data.
What the Research Says About Dosing Ranges
Clinical trials have tested CBD across an enormous range, from under 25 mg per day up to thousands of milligrams. Australia’s Therapeutic Goods Administration reviewed the literature and organized CBD doses into three tiers. Low dose is roughly 1 mg per kilogram of body weight per day or less, which works out to about 60 mg per day for an average adult. Medium dose runs from about 1 to 10 mg/kg/day. High dose, used primarily for drug-resistant epilepsy in children, reaches 10 to 50 mg/kg/day.
For context, most over-the-counter CBD products recommend somewhere between 10 and 50 mg per day. Studies on anxiety and insomnia have typically used 25 to 75 mg per day. Studies on chronic pain have used doses as low as 10 to 22.5 mg per day. These lower doses fall within what researchers classify as the low-dose range and are generally better tolerated than the high doses used in epilepsy treatment.
Where Liver Risk Enters the Picture
The most significant safety concern with CBD is liver stress. The only FDA-approved CBD medication, used to treat severe childhood seizure disorders, carries a warning about dose-related elevations in liver enzymes. At doses up to 25 mg/kg/day (which can mean over 1,000 mg daily for an adult), about 12 to 13% of patients in clinical trials showed liver enzyme levels more than three times the normal upper limit, compared to just 1% on placebo.
The critical question for everyday CBD users is whether lower doses also pose a risk. An FDA-conducted randomized trial tested doses more typical of consumer use, around 250 to 550 mg per day, in healthy adults over four weeks. Even at these moderate doses, 5.6% of participants developed elevated liver enzymes, and nearly 5% met the criteria for potential drug-induced liver injury. That’s a meaningful rate for a wellness supplement.
Below 200 mg per day, the liver safety picture is murkier. The FDA has acknowledged that data at these lower doses is limited and inconsistent. This uncertainty is part of why the UK food regulator dropped its recommended limit so dramatically. Their scientific advisors concluded that even purified CBD at levels above 10 mg per day hadn’t been convincingly shown to be safe for long-term daily use.
Common Side Effects
Beyond liver concerns, the most frequently reported side effects of CBD include drowsiness, sedation, fatigue, diarrhea, and changes in appetite. These effects generally follow a dose-response pattern, meaning higher doses produce more noticeable effects. In epilepsy trials using 10 to 20 mg/kg/day, about 32% of patients experienced drowsiness or sedation, compared to 11% on placebo. At lower doses, these effects are less common but still possible.
Sleep disruption is worth noting specifically. While many people take CBD to improve sleep, some experience the opposite at certain doses, with changes in sleep patterns appearing in clinical adverse event reports.
CBD Can Change How Your Medications Work
CBD is processed by the same liver enzymes that break down a wide range of common medications. When CBD competes for those enzymes, it can raise or lower the effective levels of other drugs in your bloodstream. Researchers have identified 57 medications where this altered concentration could be dangerous. The most notable interactions involve warfarin (a blood thinner), amiodarone (a heart rhythm drug), levothyroxine (a thyroid medication), and several seizure medications including clobazam, lamotrigine, and valproate.
If you take any prescription medication, this interaction risk is arguably more important than the dose of CBD itself. Even a relatively low dose of CBD could amplify or blunt the effects of another drug in unpredictable ways.
Long-Term Safety Is Still Unclear
One of the biggest gaps in CBD safety research is the lack of long-term data. The FDA has stated plainly that data on long-term oral CBD exposure in healthy populations is lacking. The longest safety data available comes from epilepsy treatment extension studies, where median exposure was about one year, but those patients were taking high medical doses under close supervision with regular blood work. That’s a very different situation from someone taking a daily CBD gummy for general wellness over years without monitoring.
This absence of long-term data doesn’t mean CBD is dangerous at low doses over time. It means no one has rigorously checked. The UK regulator’s conservative 10 mg limit reflects this uncertainty: when the long-term safety evidence is thin, regulators set the bar low.
Product Quality Adds Another Variable
The dose on a CBD product label may not reflect what’s actually inside. Because CBD supplements are not tightly regulated in the United States, products can vary widely in actual CBD content, and some contain contaminants like heavy metals, pesticides, or residual solvents. A proposed federal bill, the Cannabinoid Safety and Regulation Act, would require producers to register with the FDA and test products for potency, pesticides, heavy metals, and chemical byproducts, but that framework is not yet in place. Until it is, the “dose” you think you’re taking may be higher or lower than what you’re actually getting.
Practical Takeaways on Dosing
If you’re using CBD, the research points in a few clear directions. Doses under 60 mg per day fall in the low-dose category and carry the least documented risk. The UK’s conservative limit of 10 mg per day represents the most cautious official guidance currently available. Doses in the 250 to 550 mg per day range have produced measurable liver enzyme changes in healthy adults within just four weeks. And any dose of CBD can potentially interact with prescription medications processed by the liver.
Starting low and paying attention to how you feel is a reasonable approach, but it’s worth knowing that “low” in the research literature means something quite different from what many product labels suggest. The gap between the doses being sold and the doses that have been rigorously evaluated for safety remains wide.