Extended humans are artificially strengthened humans developed by the Earth Alliance's secret Extended Program, which is aimed at producing pilots for its mobile suits that would fight with the same efficiency as Coordinators. This would later expand to include having fighting capabilities on par with Coordinators. Pilots produced in the earlier phase of the project were term Biological CPU, and classified as equipment as they were viewed to be similar to the computer's CPU. Improvements were later made to the program, and the pilots produced in this later phase are called Extendeds.
- Biological CPUs had some micro-implants in their brains and glands, and were mentally conditioned to eliminate their sense of fear and increase aggression in combat; the subjects were mostly regular pilots who were given regular doses of the performance-enhancing drug Gamma Glipheptin. This drug had a negative effect on the pilots' mental stability and caused them to behave in undesirable ways during battle. It also had very brief duration, and as the effect wore off it left the pilots incapacitated with severe withdrawal symptoms, as their nervous systems began to collapse without regular doses. Their loyalty to the Alliance was guaranteed by their addiction to Gamma Glipheptin. The known pilots produced in this phase were Clotho Buer, Orga Sabnak and Shani Andras, all three were killed in battle during the closing stages of the Bloody Valentine War. Due to their required intake of drugs and harsh withdrawal symptoms, fans dubbed the trio "the Druggies", which tends to be used as an affectionate nickname rather than an insult.
- Extendeds were physically and psychologically altered through surgery, brainwashing, heavy mental conditioning, performance-enhancing drugs and extremely harsh combat training. They were more stable than the Biological CPUs, but required regular re-conditioning, especially when their block words were used to force actions from them. They also required regular physical and mental "maintenance" to keep them in a high-performance state, and to erase any "undesirable" memories they might have. Sting Oakley, Stella Loussier, and Auel Neider were the known Extendeds and all three died in combat. Auel perished at the hands of Shinn Asuka's ZGMF-X56S Impulse in a naval battle near Crete. Stella died after her GFAS-X1 Destroy was attacked by Kira Yamato's ZGMF-X10A Freedom in battle over Berlin. Sting was killed by Shinn's ZGMF-X42S Destiny in the battle for Heaven's Base.
The Biological CPUs possessed strong enough combat abilities to press even very strong Coordinators such as Kira Yamato or Athrun Zala. However, the Extendeds proved to be somewhat weaker than their predecessors. Evidence of this is the fact that they could not hold their own against characters in SEED mode while the original Biological CPU pilots did. However as the Extendeds do not rely on chemical stimulants for their prowess, they can last longer in the battlefield than the Biological CPUs. Overall, both the Biological CPUs and Extendeds could be considered analogous to the Universal Century concept of Artificial or Cyber-Newtypes, who were normal pilots enhanced to have Newtype abilities.
- The methods used to train and enhance the Extendeds are similar to the SPARTAN-III Program from the video game series Halo.