Epidiolex contains 100 mg of CBD per milliliter of oral solution. Each standard bottle holds 100 mL, which means a full bottle contains 10,000 mg (10 grams) of pharmaceutical-grade cannabidiol.
Concentration and Bottle Size
Epidiolex is a clear, colorless to yellow liquid designed to be taken by mouth. At 100 mg/mL, it is significantly more concentrated than most over-the-counter CBD oils, which typically range from 15 to 50 mg/mL. The high concentration matters because the doses used to treat seizures are relatively large, and a lower concentration would require patients to swallow impractical volumes of liquid with each dose.
The actual amount a person takes each day depends on body weight. Epidiolex is dosed in milligrams per kilogram, so a 30 kg child would take a different volume than a 70 kg adult. Because the solution is 100 mg/mL, the math is straightforward: 1 mL equals 100 mg of CBD.
What Epidiolex Is Approved to Treat
Epidiolex is the only FDA-approved CBD medication. It is indicated for seizures associated with three conditions: Lennox-Gastaut syndrome, Dravet syndrome, and tuberous sclerosis complex, in patients 1 year of age and older. These are severe, treatment-resistant forms of epilepsy where standard anti-seizure medications often fall short. The FDA approval means Epidiolex went through the full clinical trial process to prove it reduces seizure frequency in these specific conditions.
How Epidiolex Differs From Store-Bought CBD
The CBD in Epidiolex is highly purified and plant-derived, but the similarity to retail CBD products largely ends there. Over-the-counter CBD is not regulated by the FDA as a drug or a dietary supplement, which creates wide variability in what consumers actually get.
A 2017 study from the University of Pennsylvania found that nearly 70% of CBD products sold online were mislabeled. Of those, 42% contained more CBD than the label stated and 26% contained less. A 2022 Johns Hopkins study tested over 100 topical CBD products from online and retail stores and found only 24% were accurately labeled. Beyond potency problems, a 2024 analysis of 202 CBD products found heavy metals in 44 of them (lead was the most common), residual solvents like hexane and methanol in 181 products, and pesticides in 30.
Epidiolex, by contrast, must meet pharmaceutical manufacturing standards for purity, consistency, and contamination limits in every batch. When the label says 100 mg/mL, that number is verified through the same quality controls applied to any prescription drug. This consistency is one reason neurologists prescribe Epidiolex rather than recommending commercial CBD products for seizure disorders, even when CBD is readily available over the counter.
Why the Concentration Matters
If you’re comparing Epidiolex to a CBD oil you can buy at a store or online, keep in mind that “milligrams per bottle” on a retail label can be misleading. A bottle labeled “1,000 mg CBD” that contains 30 mL of liquid works out to about 33 mg/mL, roughly one-third the concentration of Epidiolex. A bottle labeled “3,000 mg” in 30 mL would be 100 mg/mL, matching Epidiolex’s concentration, but without the same assurance that the label is accurate.
The total CBD content also matters in context. A full bottle of Epidiolex at 10,000 mg is a substantial amount, but clinical doses for epilepsy can use that up quickly depending on the patient’s weight. Retail CBD users typically take far smaller amounts, often 10 to 50 mg per day, which makes direct comparisons between the two somewhat misleading. The therapeutic doses studied in Epidiolex’s clinical trials are well above what most people take with consumer products.