Dosing and use
Doses used in trials, how prescribers decide, absorption and timing.
CBD dosage guide
There is no standard CBD dose. See the doses clinical trials used for each condition, what happened, how mg and mL relate, and how prescribers set a dose.
Low-dose CBD
Australia caps pharmacist-only CBD at 150 mg a day. That limit was set for safety, not because it works. Here is what trials at or below 150 mg found.
How long CBD takes to work
Swallowed CBD reaches its peak blood level in about 2.5 to 5 hours. Whether and when symptoms change depends on the condition, and trials ran for weeks.
How long CBD stays in your system
After regular oral use, CBD has a half-life of about 2 to 5 days and can be detected in blood for weeks. Drug tests look for THC, not CBD.
Taking CBD with food
A high-fat meal raises the amount of swallowed CBD reaching the blood about 4-fold. Why that matters, and why consistency is the key point.
CBD bioavailability
Only about 6% of swallowed CBD reaches the blood on an empty stomach. How oral, sublingual, inhaled and topical routes compare, and what is unproven.
Starting CBD
What usually happens when prescription CBD is started, including dose steps, common early side effects, blood tests, and when to review if it is working.
Stopping CBD
Studies have not found a withdrawal syndrome when CBD is stopped, but people taking it for epilepsy must taper under medical advice. What the evidence says.