Genes were the origin of life. Through the incessant transmission of impulses from the body, Genes could use all sorts of nourishing substances to produce the essential factors of life, like organs and limbs. They had the ability to grasp the entirety of human's body structure.
The reason why gene potions had all sorts of mysterious effects was due to them being the geneticists' fruits of labor after researching the mythological genes. Their medicinal effects could modify the human body, penetrating deep to stimulate genes and modifying the essence of the body at the microscopic level.