Toprol XL is a brand name for extended-release metoprolol tartrate, so they contain the same active ingredient but differ in formulation. Metoprolol is the generic drug name for a beta-blocker used to treat high blood pressure and heart conditions. Toprol XL specifically refers to the extended-release version, designed to release the medication slowly over 24 hours, allowing for once-daily dosing. Generic metoprolol comes in immediate-release tablets that typically require multiple doses per day. Both forms work the same way in your body—by blocking beta-adrenergic receptors to slow heart rate and reduce blood pressure—but the extended-release formulation offers convenience and more consistent drug levels throughout the day. When prescribers specify Toprol XL, they're requesting this particular extended-release formulation rather than the immediate-release version. If your prescription says Toprol XL, you cannot simply substitute regular metoprolol tablets without consulting your doctor, as the dosing schedule and amounts differ between the two formulations. Pharmacists can often fill Toprol XL with its generic equivalent (extended-release metoprolol tartrate) at lower cost, but this substitution should be verified with your healthcare provider to ensure the dosing remains appropriate.