What happens when you take bupropion with st. john's wort?
Bupropion is an aminoketone antidepressant that inhibits the reuptake of norepinephrine and dopamine. It is widely prescribed for major depression (Wellbutrin), seasonal affective disorder (Wellbutrin XL), and smoking cessation (Zyban). Bupropion is metabolized primarily by CYP2B6 to hydroxybupropion, which retains pharmacological activity.
St. John's wort (Hypericum perforatum) is a widely sold herbal extract used for mild depression. Its active components, especially hyperforin, are potent activators of the pregnane X receptor and induce several CYP450 enzymes (3A4, 2C9, 2C19) and the P-glycoprotein transporter. While CYP2B6 induction by St. John's wort is less well characterized than CYP3A4 induction, the herb's broad enzyme-modulating effect can change bupropion exposure unpredictably.
The more clinically important problem is the seizure risk. Bupropion has a well-documented, dose-dependent risk of lowering the seizure threshold. Reported seizure rates are about 0.1 percent at standard doses and rise sharply above 450 mg/day. St. John's wort has also been associated with reduced seizure threshold in case reports and animal studies. Combining the two creates an additive risk.
Both products also influence monoamine signaling. Bupropion raises norepinephrine and dopamine, while St. John's wort raises serotonin, norepinephrine, and dopamine. Together they can produce restlessness, insomnia, tremor, palpitations, anxiety, hypertension, and the kind of activation that bupropion already tends to cause on its own.
Why is this important?
A drug-induced seizure is a serious event. It can cause physical injury, prolonged hospitalization, and, in some patients, evolution into recurrent epilepsy. Bupropion's seizure risk is the primary reason the drug is contraindicated in patients with seizure disorders, eating disorders (anorexia and bulimia, which can cause electrolyte abnormalities), and alcohol or benzodiazepine withdrawal. Adding anything else that lowers the seizure threshold, including St. John's wort, is poorly justified.
The CYP-induction interaction is harder to predict. If St. John's wort lowers bupropion exposure, the antidepressant effect may fade and the patient may relapse. If the herb is then stopped abruptly while bupropion is still being taken, enzyme activity returns to baseline over 1 to 2 weeks and bupropion levels can rise, sometimes overshooting and producing dose-dependent seizure risk, insomnia, anxiety, or hypertension.
For patients taking bupropion for smoking cessation, the herb's induction effect could undermine treatment. For patients on bupropion for depression, the combination defeats the purpose of using a single, well-characterized agent.
What should you do?
- Do not add St. John's wort to bupropion. Ask your prescriber about other options (psychotherapy, exercise, light therapy, dose adjustment, augmentation strategies).
- If you are taking St. John's wort and your prescriber wants to start bupropion, stop the herb under guidance and allow at least 1 to 2 weeks for enzyme induction to wash out before starting or titrating bupropion.
- Avoid alcohol withdrawal, very low-calorie diets, sleep deprivation, and other seizure-lowering conditions while on bupropion.
- Tell every prescriber and pharmacist about every herbal and supplement product you take, including weight-loss, energy, mood, and smoking cessation supplements.
- Seek immediate care for any seizure, unusual confusion, very high blood pressure, severe insomnia, agitation, or hallucinations.
Which specific products are affected?
Bupropion products include generic bupropion HCl IR, SR (sustained-release), and XL (extended-release), brand-name Wellbutrin SR and Wellbutrin XL, Aplenzin (bupropion hydrobromide), Forfivo XL, and Zyban (for smoking cessation). The interaction applies to all formulations. Combination products such as Contrave (bupropion-naltrexone, for weight management) are also affected.
St. John's wort is sold as standalone capsules, tinctures, and teas, and as an ingredient in many "mood," "calm," "PMS," and herbal antidepressant combination products. Common branded items include Kira, Perika, Movana, and many drugstore generics. Read the full ingredient list of any "mood support" product before adding it to a prescription regimen.
The bottom line
St. John's wort and bupropion are a poor combination. The herb may compound bupropion's seizure risk, may shift bupropion blood levels by inducing CYP enzymes, and adds redundant monoaminergic stimulation. Choose one strategy or the other, and coordinate any change with your prescriber.