Bupropion SR and XL differ mainly in how the medication is released in the body.
SR (Sustained Release) is usually taken twice daily because it releases the drug over a shorter duration.
XL (Extended Release) is designed to be taken once daily, as it releases the medication slowly over 24 hours, giving more stable blood levels and better convenience.
Even if the total daily dose looks similar (e.g., 300 mg), XL is not meant to be taken twice a day. Taking XL 150 mg twice daily can increase the risk of side effects, especially seizures in rare cases, because of higher peak levels.
Next Steps
Please follow the dosing schedule prescribed by your doctor and do not change between SR and XL formulations on your own. If you feel your current medication is not effective, consult your doctor or you could reach out to me as well.