Owned by United Pharmaceutical & Medical Supply Company and based in Jeddah, United Pharmacy says it has been serving customers for over 35 years. The cities on its “About us” page span 13 regions, among them Riyadh, Jeddah, Makkah, Madinah, Taif, Yanbu, Khobar, Dammam, Al-Ahsa, Buraidah, Abha, Khamis Mushait, Jazan, Najran, Tabuk, Hail, Arar and Sakaka.
Use the “Our branches” page to find the closest branch: search a radius of 5 km, 10 km or 15 km around where you are, or pick your city and district instead, and you'll see each branch's address, number and a link to get directions. The site doesn't say how many branches there are in total.
Source: United Pharmacy: About us