Viagra can be purchased in several ways depending on the country and regulations:

• In the UK, Viagra tablets (including 25mg, 50mg, and 100mg doses) are available to buy online from regulated pharmacies with a prescription issued after an online medical consultation. Generic sildenafil, which is the same active ingredient, is also available at a lower cost both online and in pharmacies. Viagra Connect, a version of sildenafil, can be bought over-the-counter without a prescription in the UK at pharmacies or online, although health questions will be asked to ensure suitability.

• In the US, Viagra (and generic sildenafil) requires a prescription from a licensed healthcare provider. Telehealth services offer online medical evaluations to get a prescription which can then be used to buy Viagra from pharmacies or online retailers with delivery options.

• It is important to only buy from reputable, licensed pharmacies or official online medical services to avoid counterfeit or unsafe products.

Thus, the safest and legal way to buy Viagra is to get a prescription from a doctor or an online medical service and then purchase from a licensed pharmacy or a regulated online provider. In the UK, an over-the-counter option for sildenafil (Viagra Connect) is also available at pharmacies. If location or specifics of purchase are needed, providing the country or region would help to give more precise guidance.