Which of the following can be purchased without a prescription?

In the context of pharmacy regulations, particularly concerning insulin products, these medications are classified as prescription drugs. Insulin is a critical medication for managing diabetes, and due to safety concerns, it is not available for purchase without a prescription in the United States.

All the options provided, including Humalog, Toujeo, and Novolog, are insulin formulations used for blood sugar control in patients with diabetes. Because they require careful dosing and monitoring, they have been designated as prescription medications to ensure that they are used safely and effectively under the guidance of healthcare professionals.

Therefore, stating that none of the insulins listed can be purchased without a prescription aligns with federal and state regulations that govern these powerful medications. This understanding is important for ensuring patient safety and adherence to legal standards in pharmacy practice.