CBD is widely marketed as safe and natural, but several groups of people face real risks from taking it. These include pregnant and breastfeeding women, people on common prescription medications, children, anyone with glaucoma, and those preparing for surgery. The risks range from dangerous drug interactions to liver damage and worsened medical conditions.
People Who Are Pregnant or Breastfeeding
The FDA strongly advises against using CBD during pregnancy or while breastfeeding. There is no comprehensive research on how CBD affects a developing fetus, a pregnant mother, or a breastfed baby. What does exist is concerning: high doses of CBD in pregnant animals caused problems with the reproductive system of developing male fetuses. CBD also transfers into breast milk, exposing nursing infants to its effects, which include potential liver toxicity and extreme sleepiness.
People Taking Blood Thinners
If you take warfarin or similar blood-thinning medications, CBD poses a particularly dangerous interaction. Both CBD and warfarin are broken down by the same liver enzymes, and CBD acts as a potent inhibitor of those enzymes. The result: warfarin stays in your system longer and at higher concentrations, raising your risk of uncontrolled bleeding. In one documented case, a patient’s blood-clotting time increased significantly as their CBD dose went up, ultimately requiring a 30% reduction in their warfarin dose to compensate. This interaction is not subtle, and it can be life-threatening if unmonitored.
People on Antidepressants or Psychiatric Medications
CBD interferes with the liver enzymes that process a wide range of mental health medications. This can cause those drugs to build up in your bloodstream to levels higher than intended, increasing the likelihood of side effects.
The affected medications include SSRIs like citalopram and paroxetine, tricyclic antidepressants like amitriptyline, antipsychotics like haloperidol and risperidone, and the sleep-related antidepressant mirtazapine. CBD also interacts with MAOIs (an older class of antidepressant) by slowing their breakdown, keeping them circulating in your body longer and amplifying their side effects. With amitriptyline specifically, CBD inhibits multiple enzymes involved in its metabolism simultaneously, which can lead to dangerous drowsiness and heart rhythm changes.
People Taking Anti-Seizure Medications
This one is particularly important because CBD is sometimes marketed to people with seizure disorders. While prescription-grade CBD is FDA-approved for certain types of epilepsy, combining it with other seizure medications creates significant interactions. Patients taking clobazam alongside CBD experienced somnolence and sedation at high rates, with 67% to 86% of those reporting excessive sleepiness also being on clobazam.
The combination with valproate is even more concerning for liver health. In clinical trials, the majority of patients who developed elevated liver enzymes were taking valproate alongside CBD. In one study of patients with Dravet syndrome, 100% of those who showed liver enzyme elevations were on valproate. If your seizure medication includes either of these drugs, adding CBD without medical supervision is risky.
People on Immunosuppressants or Steroids
CBD can significantly raise blood levels of immunosuppressant drugs. With tacrolimus, commonly used after organ transplants, one study found a threefold increase in drug concentrations when CBD was added. Cyclosporine levels also rise, increasing the risk of toxic side effects. For people whose lives depend on precise immunosuppressant dosing, this interaction can be dangerous.
Common corticosteroids like hydrocortisone and prednisolone are also affected. CBD slows their clearance from the body, raising the risk of steroid-related side effects like blood sugar spikes, bone thinning, and immune suppression.
People With Glaucoma
Many people assume that because marijuana has been associated with lowering eye pressure, CBD might help glaucoma too. The opposite appears to be true. A study in mice found that CBD increased pressure inside the eye by 18% for at least four hours after use. THC alone did lower eye pressure by nearly 30%, but when CBD was combined with THC, it blocked much of that benefit, reducing the pressure drop to just 17%. If you have glaucoma or are at risk for it, CBD could actively work against your treatment.
People Preparing for Surgery
CBD interacts with several drugs commonly used during anesthesia, including propofol, ketamine, midazolam, fentanyl, and various inhaled anesthetics. These interactions happen through the same liver enzyme pathways, and the practical consequences are real. Patients who use cannabis regularly have been shown to require significantly higher doses of propofol to achieve adequate sedation. CBD also makes the tools anesthesiologists use to monitor how deeply you’re sedated less reliable, by altering brain wave activity during surgery.
Beyond anesthesia itself, CBD interacts with common post-surgical pain medications including opioids like codeine, oxycodone, hydrocodone, and tramadol. If you have a procedure coming up, your anesthesiologist needs to know about CBD use so they can adjust dosing and monitoring accordingly.
Children Using CBD for Non-Seizure Conditions
While prescription CBD has proven benefits for specific childhood epilepsy syndromes, data are lacking for every other use in children. There are no published studies supporting CBD for ADHD or generalized anxiety disorder in children, despite growing reports of parents using it for these conditions. Children and adolescents under 18 accounted for 51.2% of all CBD-related cases reported to poison control centers.
The reported effects in these cases included central nervous system depression, rapid heart rate, vomiting, and in rarer instances, heart rhythm disturbances and breathing problems. At doses of 20 mg/kg/day or higher, adverse effects including drowsiness, decreased appetite, diarrhea, and liver enzyme elevations are well documented. Children on CBD for extended periods often experience weight loss and appetite suppression, which can lead to growth problems. The purity of over-the-counter CBD products is also unregulated, meaning children may be exposed to unknown contaminants.
People Taking Common Everyday Medications
The list of drug interactions extends well beyond the categories above. CBD can raise blood levels of certain cholesterol-lowering statins (specifically atorvastatin and simvastatin), beta-blockers used for blood pressure and heart conditions, antihistamines, the acid reflux drug omeprazole, antiretroviral medications used for HIV, nerve pain drugs like gabapentin and pregabalin, and the arthritis medications naproxen, celecoxib, and tofacitinib.
The common thread is that CBD inhibits several liver enzymes responsible for breaking down a huge number of medications. If your body can’t clear a drug at its normal rate, that drug accumulates, and what was a safe prescribed dose effectively becomes an overdose. The more medications you take, the higher your risk of a meaningful interaction.
People With Cannabis Allergies
Cannabis allergy is a real condition, first documented over 50 years ago. It can cause symptoms ranging from mild (runny nose, itchy eyes, skin rashes) to severe (asthma flares, throat swelling, and anaphylaxis). Contact with hemp or cannabis products can trigger contact dermatitis and hives. In one Canadian allergy clinic survey, roughly 39% of people with a history of cannabis exposure reported symptoms consistent with cannabis allergy. Because CBD is derived from the cannabis plant, people with known sensitivity to cannabis pollen, leaves, or seeds should avoid CBD products entirely.
People With Existing Liver Problems
CBD is extensively metabolized by the liver, and clinical studies have identified liver toxicity as a known risk. Elevated liver enzymes have been documented even in otherwise healthy adults. The risk is compounded when CBD is combined with other drugs that stress the liver, particularly valproate and certain other medications. If you already have compromised liver function from hepatitis, fatty liver disease, heavy alcohol use, or other conditions, adding CBD increases the burden on an organ that may already be struggling to keep up.