Medical Marijuana and CBD for Epilepsy
Epilepsy is a brain condition that causes repeated seizures. The honest answer on medical marijuana for epilepsy depends on which cannabis product you mean, so here it is in three layers.
- Prescription CBD (Epidiolex)
- In randomized trials, purified CBD added to usual medicines cut seizures more than placebo in Dravet syndrome, Lennox-Gastaut syndrome and tuberous sclerosis complex [1][2][3].
- Dispensary cannabis and store CBD
- A different set of products with weaker evidence: there are no randomized trials of them in epilepsy, and their quality is not held to a pharmaceutical standard [4].
- Your seizure medicines
- Keep taking them. CBD interacts with several of them and can strain the liver, so any cannabis product is a conversation with your doctor first [3].
What is epilepsy?
Epilepsy is a long-term brain condition in which a person has repeated, unprovoked seizures. A seizure is a sudden burst of electrical activity between nerve cells that briefly changes how someone moves, feels, behaves or stays aware. Doctors usually call it epilepsy after two or more seizures that were not set off by an obvious cause such as a high fever, low blood sugar or alcohol withdrawal [5].
It is not contagious, it is not a mental illness, and it is far more common than most people think. In the United States about 1.2% of the population has active epilepsy, roughly 3.4 million people, including about 470,000 children [6]. Worldwide, around 50 million people live with it [5].
Epilepsy vs a seizure: what is the difference?
A seizure is a single event. Epilepsy is the tendency to keep having them. One seizure does not mean you have epilepsy, which is why doctors look for the cause first.
A seizure
A one-time episode of abnormal brain activity that can last from a few seconds to a few minutes. It can be provoked by fever in a young child, a head injury, very low blood sugar, some drugs or drug withdrawal. Many people have one seizure in their life and never another.
Epilepsy
A condition of the brain that makes seizures come back without a trigger like those. It is diagnosed after repeated unprovoked seizures, or after one when tests point to a high chance of more. It is usually managed for years, often with daily medicine.
Epilepsy symptoms and warning signs
The main symptom of epilepsy is the seizure itself, and seizures look very different from person to person. Not every seizure involves falling and shaking. Some look like daydreaming, a sudden jerk or a moment of confusion, which is why they often go unnoticed for months.
Focal seizures
They start in one area of the brain. The person may stay aware but feel a strange rising feeling in the stomach, a smell or taste that is not there, or twitching on one side. If awareness is affected, they may stare, fumble with clothes or smack their lips and not remember it afterward.
Generalized tonic-clonic seizures
The type most people picture. The body stiffens, the person falls and loses consciousness, then the arms and legs jerk rhythmically. Breathing can look labored, and afterward they are often confused, sleepy and sore for hours.
Absence seizures (“zoning out”)
A blank stare for a few seconds, sometimes with fluttering eyelids, that ends as suddenly as it began. They are most common in children and can happen dozens of times a day, often mistaken for not paying attention in class.
Myoclonic and atonic (drop) seizures
Myoclonic seizures are quick, shock-like jerks of the arms or shoulders. In atonic seizures the muscles suddenly go limp and the person drops to the ground. Drop seizures are a hallmark of Lennox-Gastaut syndrome and a frequent cause of injuries.
Aura and night-time seizures
Some people get a warning a few seconds before a seizure, called an aura: déjà vu, fear, a strange smell, tingling or a change in vision. An aura is in fact a small focal seizure, and recognizing it gives time to sit or lie down safely.
Seizures can also happen during sleep. Signs worth mentioning to a doctor include waking up with a bitten tongue, unexplained muscle aches, a wet bed, blood on the pillow, or a partner who hears unusual sounds or sees jerking at night. A phone video of an episode, taken by someone nearby, helps a neurologist more than any description.
When to see a neurologist
- You or your child had a first seizure, even if it stopped on its own.
- You notice repeated staring spells, sudden jerks or unexplained falls.
- Seizures continue even though you take your medicine as prescribed.
- Side effects of your seizure medicine affect work, school, mood or sleep.
- You are planning a pregnancy or taking new medicines, including CBD.
What causes epilepsy, and is it hereditary?
Anything that disturbs the way brain cells signal to each other can cause epilepsy. Sometimes the cause is clear from a scan or a genetic test; often it is not. Globally, no cause is found in about half of all cases [5]. These are the main known causes.
Is epilepsy genetic, and does it run in families?
Sometimes. Having a parent or sibling with epilepsy raises your own chances somewhat, but most children of parents with epilepsy never develop it. Some syndromes are caused by a single new gene change that neither parent carries, so they do not run in the family at all. If epilepsy started in childhood, or several relatives are affected, a neurologist may suggest genetic testing; the result can change which medicines are chosen.
Is medical cannabis worth discussing for your seizures?
Twelve short questions about the seizures, the treatment so far and the medicines involved. The summary tells you what the research says about a situation like yours and what to bring to a doctor.
12 questions · about a minute · your answers stay in this browser
How is epilepsy diagnosed and treated? Can it be cured?
There is no single test for epilepsy. A neurologist pieces the diagnosis together from what happened during the episodes, what the brain’s electrical activity shows and what scans reveal. Usually it takes three kinds of evidence.
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Step 1
History and a seizure diary
Shows the pattern of your seizures
Dates, times, what you felt before, what others saw, how long it lasted and how you felt after. A video taken by a family member is often the most useful piece of evidence a neurologist gets.
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Step 2
EEG (electroencephalogram)
Shows the type of epilepsy
Small sensors on the scalp record the brain’s electrical activity. A normal EEG does not rule epilepsy out, so some people need a longer recording at home or a stay in an epilepsy monitoring unit, where video and EEG run around the clock.
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Step 3
MRI and blood tests
Looks for a cause
An MRI scan looks for scars, tumors or areas that developed differently. Blood tests check for infections, salt and sugar imbalances, and sometimes genes linked to epilepsy syndromes.
How epilepsy is treated
Treatment aims for no seizures with as few side effects as possible. Most people start with one medicine, and the plan changes only if seizures continue or side effects get in the way.
Seizure medicines
Called antiseizure medicines. Common ones include levetiracetam, lamotrigine, valproate, carbamazepine, oxcarbazepine, topiramate, lacosamide and clobazam. Side effects depend on the drug: sleepiness, dizziness, tiredness, mood changes, weight change or rash are the usual complaints, and some need regular blood tests.
Surgery
If seizures always start in one small area of the brain that can be safely removed or disconnected, surgery can stop them or make them much rarer. Candidates are assessed at a specialist epilepsy center.
Diet therapy (ketogenic)
A very high-fat, very low-carbohydrate diet, or a gentler modified version, run with a dietitian. It is used mainly in children with hard-to-treat epilepsy and is a medical treatment, not a lifestyle diet.
Nerve stimulation (VNS)
A small device placed under the skin of the chest sends regular pulses to the vagus nerve in the neck. It rarely stops seizures completely but often makes them fewer or milder. Newer devices stimulate the brain directly.
Drug-resistant epilepsy
Drug-resistant (or intractable) epilepsy means seizures keep happening even after well-chosen medicines were tried at proper doses. It is the situation in which surgery, diet therapy, nerve stimulation and prescription CBD are usually discussed, and it is the group in which the main CBD trials were done [3][1][2].
Can epilepsy be cured?
For many people it can be controlled, and for some it goes away. With the right diagnosis and treatment, up to 70% of people with epilepsy could live without seizures [5]. Some childhood epilepsies fade with age, and surgery can end seizures for carefully selected patients. Others need lifelong treatment. No medicine, including cannabis or CBD, has been shown to cure epilepsy; what the research measures is how much seizures drop.
What the research shows about CBD · Seizures and medical cannabis
How to help someone having a seizure
Most seizures stop on their own within a few minutes. Your job is not to stop the seizure but to keep the person safe until it ends. Here is what to do, in order [7].
- Stay with them and look at the time. Note when the seizure started so you know how long it lasts.
- Clear the space. Move hard or sharp objects away and put something soft, like a folded jacket, under their head.
- Loosen anything around the neck. Undo a tie, collar or scarf and remove glasses.
- Roll them onto their side once the jerking stops. This is the recovery position: lying on one side, top knee bent forward to keep them steady, head tilted slightly back so saliva can drain and the airway stays open.
- Stay until they are fully awake. Speak calmly, tell them what happened and where they are. Confusion and sleepiness afterward are normal.
- Follow their seizure plan. If they carry a rescue medicine or a written plan, use it as it says.
Do not
- Put anything in their mouth. A person cannot swallow their tongue.
- Hold them down or try to stop the movements.
- Give food, water or pills until they are fully alert.
- Leave them alone until they are aware of their surroundings.
Call 911 if
- The seizure lasts longer than 5 minutes [7].
- Another seizure follows soon after, or they do not wake up in between.
- They have trouble breathing or waking afterward.
- They are injured, pregnant, have diabetes, or the seizure happened in water.
- It is their first seizure ever, or you do not know their history.
Even if you did not call 911, a hospital visit or same-day call to their doctor makes sense after a first seizure, a seizure that looked different from usual, or one followed by a head injury.
Living with epilepsy: long-term effects, safety and disability
Most people with epilepsy work, study, raise families and drive once their seizures are under control. The long-term effects depend on how well seizures are controlled, what caused the epilepsy, and the side effects of treatment. These are the questions people ask most.
Memory and thinking
Epilepsy can affect memory, especially when seizures start in the temporal lobe, are frequent, or medicines cause drowsiness. Problems with attention and word-finding are common complaints. Better seizure control and a medicine review often help.
Brain damage and SUDEP
Brief seizures rarely cause lasting brain damage, but a seizure that lasts longer than five minutes is an emergency [7]. Sudden unexpected death in epilepsy (SUDEP) is rare: each year about 1 in 1,000 adults with epilepsy die from it, mostly when tonic-clonic seizures are uncontrolled [8].
Driving
Every state lets people with epilepsy drive once they have been seizure-free for a set period, but the period and the doctor’s paperwork differ by state. Cannabis adds a separate rule: driving while impaired is illegal everywhere, with or without a card.
Work and safe jobs
Most jobs are open to people with epilepsy. Roles that involve heights, heavy machinery, open water or commercial driving may be restricted while seizures continue. You do not have to disclose epilepsy unless you need an accommodation.
Screens, games and flashing lights
Only about 3% of people with epilepsy have seizures triggered by flashing lights or patterns [9]. If you do, games and movies with strobe warnings are the ones to skip; playing in a well-lit room, sitting back from the screen and taking breaks lower the risk.
Sleep safety
For night-time seizures, families often use an anti-suffocation pillow with air holes, a low bed or a mattress on the floor, and a bed alarm or wearable monitor that detects shaking. None is a guarantee, but they help someone respond in time.
Is epilepsy a disability?
Yes, in two separate senses. At work, epilepsy is a disability under the Americans with Disabilities Act, so an employer must provide reasonable accommodations, such as schedule changes or time off for appointments, unless that causes undue hardship [10]. For disability benefits, the Social Security Administration lists epilepsy in its Blue Book under listing 11.02: you may qualify if seizures continue at a set frequency for at least three consecutive months despite following prescribed treatment [11]. A neurologist’s records and a seizure diary are the key evidence for both; a disability attorney or your local legal aid office can help with the application.
Cannabis laws by state: rules on driving and protection at work differ from state to state.
Why is cannabis discussed for epilepsy?
Because for a large group of people the usual tools are not enough. Seizures keep coming after one medicine, then another. Side effects pile up. Every outing carries the question of whether a seizure will happen at work, behind the wheel or during the night. Parents of a child with Dravet or Lennox-Gastaut syndrome often go years without a full night’s sleep. And then come the mixed messages: a CBD oil from a store, a prescription called Epidiolex, a medical marijuana card. Are they the same thing? Is any of it safe with the medicines you already take?
This page sorts that out, and the starting point is biology. The body has its own endocannabinoid system: signaling molecules and receptors that help calm nerve cells after they fire. Cannabis plant compounds act on parts of this system and on several other targets in the brain. THC is the compound that causes a high. CBD (cannabidiol) does not, and its effect on seizures does not appear to run mainly through the classic cannabinoid receptor that THC uses [12]. Lab studies point to several routes instead.
Calming overexcited nerve cells
In lab studies, CBD reduced the overexcitement of nerve cells and the spread of seizure activity, through routes that differ from standard seizure medicines [1]. It also strengthened the current through KCNQ2, a potassium channel that works as a brake on nerve firing [13].
Adenosine signaling
Adenosine is one of the brain’s natural calming signals. In lab studies, CBD blocked a transporter called ENT1 that clears adenosine away, so more of it stays around nerve cells [12][14].
GPR55 and TRPV1 receptors
Both receptors can make nerve cells more excitable by raising calcium inside them. In lab studies, CBD blocked GPR55 and desensitized TRPV1, which turns that signal down [4][12].
Sodium and calcium channels
These channels are the gates that let nerve cells fire, and many seizure medicines target them. In lab studies, CBD slowed voltage-gated sodium and calcium channels [12].
Lab findings explain why researchers became interested. They do not show that a product works in people; that is what the trials below were for.
What does the research show about CBD for seizures?
The strongest evidence on cannabis for epilepsy is about one product: purified, prescription CBD, added to the medicines people were already taking. In randomized trials in three rare, severe syndromes it reduced seizures more than placebo [3][1][2]. It did not replace standard treatment and it did not stop seizures for most people. Evidence on other cannabis products is far thinner, and it helps to know which kind of study says what.
How strong is each kind of evidence?
Studies higher on this list tell you more about whether something works in people. Pick a level to see what it found.
Randomized trials
People are assigned by chance to CBD or a look-alike placebo, and neither they nor their doctors know which. This is the fairest test of whether a treatment works, but it only tells you about the kind of patients who took part.
- Tuberous sclerosis complex: 224 children and adults over 16 weeks; seizures fell 48.6% at 25 mg/kg/day against 26.5% on placebo (2021) [3].
- Dravet syndrome: 198 children and teenagers over 14 weeks; convulsive seizures fell 29.8% more than with placebo at 10 mg/kg/day (2020) [1].
- Lennox-Gastaut syndrome: 225 patients over 14 weeks; drop seizures fell 21.6% more than with placebo at 20 mg/kg/day (2018) [2].
- In every trial CBD was an add-on to existing seizure medicines in people whose seizures were drug-resistant.
Reviews
Reviews pool or compare many studies. A systematic review with a meta-analysis gives the widest view, but it can only be as good as the trials it collects.
- A 2023 network meta-analysis of Dravet syndrome trials, 680 participants in total, found CBD was less likely to produce a seizure response than fenfluramine or stiripentol, two other add-on medicines [14].
- The same analysis recorded raised liver enzymes in 15% of people taking CBD [14].
- A 2021 review summarized long-term open-label follow-up of 681 patients, in which CBD continued to be used beyond the short trials [4].
- A 2026 review reported that the drop in seizures was larger in people who also took clobazam than in those who did not [15].
Observational studies
These follow patients in everyday care without a placebo group. They show how a medicine behaves in the real world, but cannot prove it caused an improvement.
- A Swedish registry of 106,315 people with epilepsy found that 42% of men who started CBD were still taking it a year later, compared with 64% for brivaracetam, another newer medicine (2025) [16].
- In a real-world study of severe childhood epilepsies, CBD was less likely to work in people also taking valproate (2025) [17].
- Studies in adults and in epilepsies other than the three syndromes show mixed results: some report benefit, others more modest effects [18][19][20].
Lab and animal
Experiments on cells and animals explain how a compound might work. They cannot tell you whether it helps people or at what dose.
- In lab studies, CBD boosted the current through the KCNQ2 potassium channel, a natural brake on nerve firing [13].
- In lab studies, CBD blocked mechanosensitive potassium channels called TRAAK and TREK [21].
- In animal studies of a mitochondrial disease, all mice given CBD beforehand survived heat-triggered seizures (2024) [22].
Randomized trials of prescription CBD
Each row is one trial. “Result vs placebo” is how much more seizures dropped with CBD than with a placebo. Scroll the table sideways on a phone.
| Condition | Who took part | Patients | Length | Doses studied (mg/kg/day) | Result vs placebo | Source |
|---|---|---|---|---|---|---|
| Tuberous sclerosis complex | Children and adults aged 1 to 65 with drug-resistant seizures | 224 | 16 weeks | 25 and 50 | Seizures fell 30.1% more at 25 and 28.5% more at 50 | JAMA Neurology, 2021 [3] |
| Dravet syndrome | Children aged 2 to 18 with treatment-resistant seizures | 198 | 14 weeks | 10 and 20 | Convulsive seizures fell 29.8% more at 10 and 25.7% more at 20 | JAMA Neurology, 2020 [1] |
| Lennox-Gastaut syndrome | Children and adults not controlled by usual medicines | 225 | 14 weeks | 20 (result reported here) | Drop seizures fell 21.6% more | New England Journal of Medicine, 2018 [2] |
All three trials added CBD to existing seizure medicines. Numbers are differences from placebo, not the total drop.
What CBD doses were used in the studies?
Trial doses were measured in milligrams per kilogram of body weight per day: 10 and 20 mg/kg/day in Dravet syndrome [1], 20 mg/kg/day in Lennox-Gastaut syndrome [2] and 25 and 50 mg/kg/day in tuberous sclerosis complex [3]. The higher doses did not reduce seizures more, but they did bring more side effects. Prescription CBD is started low and raised step by step by the prescribing doctor, and an expert consensus panel has published guidance on how to adjust it [23]. CBD also lingers: its elimination half-life is about 24 to 60 hours, and only about 6% of a swallowed dose reaches the bloodstream, so food and timing change how much is absorbed [12].
48.6% fewer seizures [3]
People with tuberous sclerosis complex taking 25 mg/kg/day of CBD had 48.6% fewer seizures over 16 weeks, compared with 26.5% fewer on placebo [3].
Limit: most participants took several other seizure medicines, seizure types were not confirmed by video-EEG, and the placebo group improved more than expected [3].
How much did seizures drop compared with placebo?
“It helps” is not a useful answer for someone deciding whether to try a treatment. The useful question is how much. In trials, seizures also drop in the placebo group, partly because people get extra attention and partly by chance, so the fair measure is the gap between CBD and placebo. Here are those gaps from the three randomized trials.
How to read it: the dot is the trial’s result, the bar around it is the likely range (95% confidence interval), and the gray line marks “no difference from placebo.” The further right a dot sits, the bigger the extra drop in seizures with CBD.
Tuberous sclerosis complex (all seizures counted in the trial)
Dravet syndrome (convulsive seizures)
Lennox-Gastaut syndrome (drop seizures)
In all three syndromes, seizures dropped roughly a fifth to a third more with CBD than with placebo, and doubling the dose did not add to the effect [3][1][2].
Show as a table
| Condition and seizures counted | Dose (mg/kg/day) | Extra drop vs placebo | 95% CI | Source |
|---|---|---|---|---|
| Tuberous sclerosis complex, all trial seizures | 25 | 30.1% | 13.9–43.3 | 2021 [3] |
| Tuberous sclerosis complex, all trial seizures | 50 | 28.5% | 11.9–42.0 | 2021 [3] |
| Dravet syndrome, convulsive seizures | 10 | 29.8% | 8.4–46.2 | 2020 [1] |
| Dravet syndrome, convulsive seizures | 20 | 25.7% | 2.9–43.2 | 2020 [1] |
| Lennox-Gastaut syndrome, drop seizures | 20 | 21.6% | 6.7–34.8 | 2018 [2] |
Is Epidiolex the same as medical marijuana from a dispensary?
No. Epidiolex is a prescription drug: purified CBD, made to pharmaceutical standards, approved by the FDA in 2018 for seizures in Lennox-Gastaut and Dravet syndromes [24] and later for tuberous sclerosis complex. Medical marijuana from a dispensary is a range of plant-based products bought under state law with a physician’s recommendation. A medical card does not get you Epidiolex, and a prescription for Epidiolex does not require a card.
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Who gives it
Epidiolex (prescription)
Your neurologist or another doctor writes a prescription, and you fill it at a pharmacy.
Dispensary product (with a card)
A licensed physician writes a recommendation, you register with your state program, and you buy at a state-licensed dispensary.
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What is in it
Epidiolex (prescription)
Purified CBD in an oral liquid, with only trace amounts of THC.
Dispensary product (with a card)
Depends on the product: CBD, THC or both, plus other plant compounds, as flower, oils, tinctures, edibles, vapes or topicals.
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Tested in randomized trials
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Dose and purity
Epidiolex (prescription)
Standardized: every bottle holds the stated amount, and the dose is set per kilogram of body weight.
Dispensary product (with a card)
Not held to pharmaceutical quality control, so the real CBD and THC content can differ from the label [4].
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Do you need a card?
Epidiolex (prescription)
No. A prescription is all you need, and a card does not replace it.
Dispensary product (with a card)
Yes, to buy as a patient in a state medical program, where a card can also mean higher limits and lower taxes.
How a medical cannabis evaluation works · Cannabis laws by state
What about THC, whole-plant cannabis and other forms?
Many people ask about whole-plant cannabis, or products that combine THC and CBD. The honest answer is that the evidence is much weaker than for purified CBD. What exists comes mostly from observational reports and family surveys, not from randomized trials like the ones above [4]. The effects and risks of THC do not carry over to a CBD-only product, and the reverse is also true: a trial of purified CBD tells you nothing certain about a high-THC product. Cannabinoids can also cause harm here; a French drug-safety review collected reports of seizures linked to cannabinoid use [25]. If you are considering a product with THC, the ratio of THC to CBD is something to set with your neurologist, not by trial and error.
Ways cannabis is used, and what applies to each
Cannabis is not only smoked. Here is what is specific to each form; which one fits you, if any, is your doctor’s call.
Smoking
Joints, blunts, pipes and bongs. Smoke is a product of burning plant material and irritates the airways and lungs. Effects start within minutes, which makes the dose hard to keep steady from day to day.
Vaping and dabbing
Dry-herb vaporizers, oil cartridges and pens, and dabbing of concentrates such as wax, shatter or rosin. There is no smoke, but a hot aerosol still passes through the same airways. Concentrates can carry a very high THC dose.
Edibles and capsules
Gummies, chocolates, baked goods, drinks, capsules and oils taken by mouth. Effects start later and last longer, and a second serving taken “because the first didn’t work” is a common cause of taking too much. Only about 6% of swallowed CBD reaches the bloodstream, and it passes through the liver first [12].
Under the tongue (tinctures, sprays)
Tinctures and oils held under the tongue, or sprays used inside the cheek. Part of the dose is absorbed through the mouth lining and part is swallowed, so the liver and drug interactions still apply.
On the skin (topicals, patches)
Creams, balms and ointments act mostly where they are applied and are not a seizure treatment. Transdermal patches are different: they are designed to deliver cannabinoids into the bloodstream.
Prescription cannabinoids (dronabinol, nabilone, Epidiolex)
FDA-approved medicines filled at a pharmacy, not dispensary products. Dronabinol (Marinol, Syndros) and nabilone (Cesamet) contain THC or a THC-like compound and are prescribed for nausea and appetite, not for seizures. Epidiolex is the only one approved for seizures.
What applies to every form: CBD and THC are processed by the liver and interact with several seizure medicines; both can add to sleepiness; and driving while impaired is illegal and unsafe, especially if seizures are not fully controlled. Details are in the safety section below.
What science doesn’t know yet
The trials above answered one narrow question well. Many of the questions you might actually have are still open, and it is better to know that before you decide anything.
What this means for you: talking to your doctor
If your seizures are well controlled, there is little evidence that adding cannabis would improve things, and some reason for caution. If they are not, it is reasonable to ask about it. What you can realistically expect from prescription CBD, based on the trials, is fewer seizures rather than none, side effects that need watching, and blood tests along the way. What you should not expect is a replacement for your current medicines or a product that works the same for everyone.
Where to start depends on where you are. If you are an adult whose seizures continue despite treatment, the eligibility check on this page is a quick first step. If you are still reading up, the research and safety sections are the core of this page. If you already have a card, your renewal is a new evaluation with a physician licensed in your state; if you moved, the laws of your new state decide whether your card still works.
Bring to your appointment
- A list of all your seizure medicines with their doses
- Your seizure diary for the last few months
- Your most recent liver blood tests, if you have them
- Other prescriptions, especially everolimus or sirolimus
- Any CBD or cannabis product you already use, or a photo of its label
Questions to ask
- Could cannabis or CBD interact with the medicines I take now?
- Which type of product, if any, makes sense for me, and what should I avoid?
- How and how often will my liver be checked?
- How should I tell my neurologist, and what should I track in my diary?
Is CBD safe with seizure medications?
It can be used with them, and in the trials it always was, but not without supervision. CBD changes how the body handles several seizure medicines, and it can raise liver enzymes, the proteins doctors measure in a blood test to see whether the liver is under strain. In the tuberous sclerosis trial, liver enzymes (ALT or AST) rose above three times the upper limit of normal in 18.9% of people taking CBD (randomized trial, 2021) [3]. Across Dravet syndrome trials the pooled figure was 15% [14]. These rises were found by routine blood tests, which is why testing is part of treatment.
Side effects in the tuberous sclerosis complex trial
| Side effect | CBD 25 mg/kg/day [3] | CBD 50 mg/kg/day [3] | Placebo |
|---|---|---|---|
| Diarrhea | 31% | 56% | 25% [3] |
| Sleepiness | 13% | 26% | 9% [3] |
| Lower appetite | 20% | 23% | 12% [3] |
| ALT (liver enzyme) raised | 12% | 22% | 0% [3] |
| AST (liver enzyme) raised | 11% | 19% | 0% [3] |
Share of participants who reported each effect over 16 weeks [3]. Randomized trial of 224 people, 2021 [3].
The same three effects led the list in the other trials: in Lennox-Gastaut syndrome, sleepiness affected 30%, lower appetite 26% and diarrhea 15% of people at 20 mg/kg/day [2]; in Dravet syndrome, fever and tiredness also appeared in more than a fifth of children [1].
Check your medicines against the studies
Tick the medicines you take. Names are on your pharmacy label; the generic name is usually printed under the brand name.
Pick a medicine to see what the studies recorded.
Valproate (Depakote, Depakene)
What was seen: a higher risk of liver enzyme rises above three times normal when CBD was added [3]. In the Dravet trial, 12% of children on CBD plus valproate had such rises [1]. A real-world study also found CBD less likely to work alongside valproate [17].
Type of data: clinical, measured in patients.
What doctors usually do: check liver blood tests before starting and regularly after, and adjust doses if enzymes rise.
Clobazam (Onfi, Sympazan)
What was seen: CBD raised the level of clobazam’s active breakdown product, with more sleepiness, rash and pneumonia, and also a larger drop in seizures [3][15].
Type of data: how the body processes the drug, plus clinical outcomes.
What doctors usually do: watch for drowsiness and lower the clobazam dose if sedation appears.
Stiripentol (Diacomit)
What was seen: stiripentol slows the liver enzymes that clear other drugs, which raises their levels, and it dampened the rise in clobazam’s breakdown product caused by CBD [4].
Type of data: how the body processes the drug.
What doctors usually do: review all doses together and check blood counts and liver tests on schedule.
Everolimus (Afinitor)
What was seen: CBD increased everolimus levels in the blood [12][26].
Type of data: how the body processes the drug, seen in patients with tuberous sclerosis complex.
What doctors usually do: measure everolimus blood levels and lower its dose if needed [23].
Sirolimus (Rapamune)
What was seen: prescription CBD raises blood levels of oral mTOR inhibitors, the drug family sirolimus belongs to [23].
Type of data: how the body processes the drug.
What doctors usually do: monitor sirolimus levels and reduce its dose if they climb [23].
Another seizure medicine
What was seen: in the trials CBD was added to many different medicines, but most combinations were not analyzed one by one [1]. Medicines that speed up the liver enzymes CYP3A4 and CYP2C19 can lower CBD levels; an expert panel noted the prescription CBD dose may need to be up to twice as high with them [23].
Type of data: how the body processes the drug.
What doctors usually do: this does not mean there is no interaction. Ask your neurologist or pharmacist about your exact medicine.
Not sure what you take
What was seen: the studies cannot tell you anything about a medicine you cannot name.
Type of data: none yet.
What to do: look at the pharmacy label or ask your pharmacist for a printed list of your medicines, and bring it to your appointment. The checklist above has a spot for it.
How to get a medical marijuana card with epilepsy
If you and your doctor decide that medical cannabis is worth discussing, a card is the legal way to buy it as a patient in your state. Everything with us happens online, and there is nowhere to drive. The path has three steps on our side and one on the state’s.
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Step 1
Apply online
About 5 minutes
Choose your state, answer a short health questionnaire and list your seizure medicines. If you have notes from your neurologist, have them at hand.
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Step 2
Appointment with a physician licensed in your state
About 15 minutes; you agree on the time with the doctor
A one-on-one, private conversation about your seizures, your medicines and whether medical cannabis fits. Keep an hour free around the slot rather than a single minute, since a doctor can run late with the patient before you.
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Step 3
Signed recommendation
Usually within 24–48 hours after the appointment
If the physician finds that you qualify, you receive a signed recommendation. If not, the doctor explains why.
After that, in most states you register with the state’s medical cannabis program and the state issues your card. How long that takes is set by the state, not by us; your state’s rules list the current steps and fees.
Across 250 reviews from patients in the states where we are licensed. We do not sort them by score and do not hide the low ones.
- 150,000+patients evaluated — everyone who has been through an appointment with us, in every state where we are licensed
- Since 2017doing only this: online evaluations for medical cannabis programs, and nothing else on the side
What your state’s law decides for you
Four things change from one state to the next, and each of them matters to someone with epilepsy. Your state’s laws and regulations page lists the current rules for every one of them.
- Legal status. Some states have a full medical program, some allow both medical and recreational sales, and a few allow only low-THC or CBD-dominant products for seizure disorders. That last group matters here, because the products you could buy may be narrower than the word “medical cannabis” suggests.
- Possession limits. Each program caps how much a patient may buy and carry over a set period. Medical limits are often higher than recreational ones, which matters if you use a product every day rather than now and then.
- Taxes. Many states tax medical purchases less than recreational ones, and some exempt patients from part of the sales tax. The exact rates are set by each state and change; our article on medical vs recreational cannabis taxes explains how the difference works.
- Home cultivation. Some programs let patients grow a limited number of plants at home, others forbid it entirely. Homegrown cannabis has no lab-measured CBD or THC content, which is a real problem when seizure control depends on a steady dose.
What a card costs, and whether it saves money
There are two separate costs. One is the evaluation with a physician licensed in your state. The other is the state’s own registration fee, which the state sets and collects, and which some states reduce for patients on certain benefits. A card usually needs renewing, often every year, so both costs come back.
Whether the card pays for itself depends on how much you buy and on your state’s tax rules. Someone who uses a CBD-dominant oil every day buys far more over a year than an occasional user, so the tax difference between medical and recreational purchases adds up faster. Because the rates differ by state and change, we do not put a figure here; check the tax comparison and your state’s rules. If the physician finds you do not qualify, you get an explanation of why, not a recommendation you cannot use.
Children and teenagers with epilepsy
Most of the strongest evidence on this page comes from children. The Dravet syndrome trial enrolled only children and teenagers aged 2 to 18 [1], and the tuberous sclerosis trial included children from age 1 [3]. For a child with Dravet syndrome, Lennox-Gastaut syndrome or tuberous sclerosis complex, the established route is prescription Epidiolex from a pediatric neurologist, not a dispensary product [24]. How long-term use affects a developing child’s brain still needs longer study [12].
Access through a state program works differently for minors. Each state decides whether patients under 18 may join at all, and programs that allow it generally require a parent or legal guardian to consent and to register as the child’s caregiver, who then buys and gives the product. The age limits, the number of physician sign-offs and the caregiver rules are set by your state; its laws page lists them, and our article on marijuana and minors explains the general picture.
Does epilepsy qualify for a medical marijuana card?
In most states with a medical program, yes, but the wording differs. Some lists say “epilepsy,” others “seizures” or “seizure disorders,” and some leave it to the physician to decide on any serious condition. A few states allow only low-THC CBD products for seizures. Check how your state words it on its laws page, and read how an evaluation works before you apply. The physicians who see our patients are licensed in the state where you live.
Medical card or the recreational market?
In states where adults can buy recreational cannabis, a medical card can still make a difference: many states charge patients lower taxes, allow higher possession limits, and let adults below the recreational age buy as patients. Medical dispensaries also tend to carry measured CBD-dominant products and staff used to medical questions. The honest downsides are a card fee and a renewal, usually every year, which means a new evaluation with a physician licensed in your state.
Your legal protections, and their limits
- Firearms. Cannabis remains more tightly controlled under federal law than under state medical programs, and the federal firearms purchase form (ATF Form 4473) asks about marijuana use regardless of state law. Get legal advice before combining a card with gun ownership.
- Work. Protection for employees who use medical cannabis differs by state, and safety-sensitive and federal jobs often keep drug-free rules regardless.
- Privacy. State patient registries are confidential, and your evaluation is a private medical appointment protected like any other health record.
- Driving. Driving while impaired is illegal with or without a card, and your state’s seizure-free rules for drivers still apply.
Epilepsy and medical cannabis: common questions
Is epilepsy hereditary?
Sometimes. Genes play a role in many epilepsies, and having a close relative with epilepsy raises the chance somewhat, but most children of a parent with epilepsy never develop it. Some severe syndromes, such as Dravet syndrome, usually come from a new gene change that neither parent carries. A neurologist or genetic counselor can tell you what applies to your family.
Can epilepsy go away?
For some people, yes. Several childhood epilepsies fade by adulthood, surgery can end seizures for selected patients, and with the right treatment up to 70% of people with epilepsy could live without seizures [5]. After years without seizures, some people stop their medicine under a doctor’s supervision. Others need treatment for life.
Does epilepsy qualify for disability?
It can. Epilepsy is a disability under the ADA, which protects you at work [10]. For Social Security disability benefits, epilepsy is listed in the Blue Book under listing 11.02, and you may qualify if seizures continue at a set frequency despite following your treatment [11]. Medical records and a seizure diary are the key evidence.
Is CBD legal for epilepsy?
Prescription CBD (Epidiolex) is legal in every state with a prescription. Hemp-derived CBD products are legal under federal law if they stay under the federal THC limit, but states regulate them differently and their quality varies. Cannabis products with more THC are legal only under your state’s medical or adult-use program.
Can I buy Epidiolex at a dispensary?
No. Epidiolex is a prescription drug sold through pharmacies. A medical marijuana card gives access to dispensary products, which are different products with different evidence behind them. You can ask your neurologist about a prescription whether or not you have a card.
Will cannabis replace my seizure medicine?
Is an online medical marijuana appointment legal?
Yes, in states that allow it. This is telemedicine: a real medical appointment held online with a physician licensed in your state, who follows the same rules as in an office. Where a state requires an in-person visit, it says so in its program rules, and we follow them.
Does my medical card work in other states?
Sometimes. This is called reciprocity, and each state decides for itself whether to honor out-of-state cards, often only for visitors and sometimes with a short registration. Check the destination state on our laws page before you travel, and never carry cannabis across state lines.
What if I lose my card?
Your card is issued by your state’s program, so a replacement comes from the state as well, usually through the same online account you registered with, sometimes for a small fee. Your physician’s recommendation stays valid until its expiration date.
Can I drive if I have epilepsy and a medical card?
Two sets of rules apply. Your state decides when someone with epilepsy may drive, usually after a seizure-free period. Separately, driving while impaired by cannabis is illegal in every state, card or not.