The group was founded by formerly mechanically augmented Iraq and Afghanistan war veteran, Zeke Sanders. However, Zeke claimed that the retinal prosthesis he had installed under the Recycle Military Bill drove him to doing horrible things during the wars, and eventually removed it. Following this, he founded the Purity First, a group that gathered people with a similar hate for human augmentation.
According to Lazarus, most of the group's members are "street kids and orphans turned rebels", he also states in his radio segments that the group is backed by a mysterious backer with ties to the Illuminati, though whether this is true is unknown.
They are responsible for multiple acts of breaking and entering, vandalism, theft, and arson. Most of their attacks involve empty buildings with little security presence, and usually no fatalities.
In 2027, Anna Kelso recalls that the group is responsible for several assaults and murders across the United States. They have similar intentions to the less extreme group, Humanity Front, though they accomplish their goals through violence, and not simple protesting.
Early in Human Revolution, they take over a Sarif Industries processing and assembly plant in Milwaukee Junction, where the prototype Typhoon Explosive System was being prepared for manufacturing. Adam Jensen is sent in to resolve the situation, and eventually finds Zeke Sanders, the group's leader. How the situation is resolved is up to the player.
After the Aug Incident the organization lost its relevancy. With the cause of augmentation critically undermined and the mainstream view of it shifting to extreme negativity, Purity First essentially achieved its aims. In 2029 it is actively monitored by Task Force 29, but due to a lack of activity since the incident is considered inactive and possibly disbanded.
- The principle of the anti-augmentation group was also used in Deus Ex: Invisible War with the Knights Templar.
- Team Fortress 2 features a mechanical arm called the "Purity Fist" for the Heavy.
- The Purity First garb resembles garments worn by Christian monks.