Planet occupied by a transplanted human culture, the Pangarans, who have developed a drug they call "tretonin" by processing living Goa'uld symbiotes. Tretonin allows select members of the population to live a long life in perfect health, taking advantage of the symbiote's natural healing powers. The Pangarans are otherwise less advanced than Earth.
Pangar was once a base of operations for the Goa'uld System Lord Ra. There, he imprisoned Egeria, the mother to all Tok'ra symbiotes. Though it was believed that Ra killed her, he in fact imprisoned her in a stasis jar and buried her deep inside his temple. The Pangarans unearthed her sometime in the 1950s, Earth time, and she died there about 50 years later.
Ra was defeated by the Goa'uld Shaq'ran, who then used Pangar as a base. The planet was long since been abandoned by the Goa'uld, allowing the Pangaran society to develop naturally.
Cure - SG-1 visits Pangar, a world where the people are perfectly healthy, but possess a dark secret.
Evolution, Part 2 - Teal'c references Egeria's experience on Pangar, when she once made "blank slates" of all her children, much like Anubis was now doing to make his super-soldiers subservient.