- LuthorCorp clones
- Emily Dinsmore was cloned by her father Pete Dinsmore, under Lionel Luthor's supervision, and with the aid of LuthorCorp. He was able to produce a duplicate copy of her but this clone was unhealthy, unstable, and grew up into a teenage girl at an accelerated rate.
- Adrian Cross was infused with the same memories that Grant Gabriel had of childhood. He alleged to have been the first clone to survive Project Gemini, but said his body did not hold up well after his creation. He claimed that his body was aging on overdrive and he would be dead by Christmas, adding to his sense of urgency to expose Lex.
- LX-13 was constructed at Cadmus Labs by Lex Luthor and was preserved there so Lex could use his body parts and organs to revive his decimated body. Unfortunately for Lex, he died before he could use this clone's body parts to heal himself, and as such, this clone was ill-minded, cold, ruthless, and was unhealthy, and he aged rapidly.
- Conner Kent was constructed at Cadmus Labs by Lex Luthor and was preserved there with the other clones. He too aged rapidly although he wasn't as unhealthy as the other clones. When his Kryptonian powers and abilities kicked in, his healing factor cured him completely.
- Victims of Chrissy Parker
- Troy Turner was rapidly aged by Chrissy Parker after she kissed him and sucked the youth out of him. (Redux)
- Russell Burton was rapidly aged by Chrissy Parker after she kissed him and sucked the youth out of him. (Redux)
- Evan Gallagher also possessed accelerated growth. Evan, the son of Karen Gallagher, was a Smallville High School student, and also a metahuman, who used to short out computer monitors. Karen was impregnated by Tanner Sutherland at a party, and Evan was born one week later. (Ageless)
- Cursed by magic
- Alec Abrams is a young boy who was cursed by a magical comic book and as a result, aged several years and became the superhero Warrior Angel.
The process was for aging clones to adulthood was first developed under the supervision of Lionel Luthor, by the LuthorCorp geneticist Pete Dinsmore. Dinsmore first applied tested the process on a series of infant rabbits, which he was successful in aging to adulthood. With this success, Dinsmore attempted to clone his deceased daughter Emily, and then applied the experimental process to accelerate her aging so that she would be approximately the same age as the original Emily when she died. The acceleration process involved the introduction of kryptonite into her biology.
However, the aging process resulted in severe side effects. Specifically, the Emily's moral center was damaged beyond repair, which resulted in her becoming a childhood sociopath with no internal concept of right and wrong. She also gained the ability to move at super speed.
Lionel later abandoned the project after Emily murdered her father, and it was discovered that Emily's accelerated aging would not slow down.