The Athletics Integrity Unit has imposed a three-year suspension on sprinter Mark Otieno and a two-year penalty on marathon runners Alice Jepkemboi Kimutai and Johnstone Kibet Maiyo.
Before the 100-meter qualifying rounds at the Tokyo Olympics, Otieno, 29, tested positive for the illegal anabolic steroid methandienone.
It meant he was barred from competing.
The three-time national 100-meter champion Otieno's suspension will begin with the Games and finish in July 2023.
The Porto Marathon champion in November, Kimutai, was placed on indefinite leave after testing positive for the male hormone testosterone on November 16.
The prohibition on Maiyo began on July 20 because of a positive erythropoietin test result.
Despite having 55 athletes serving penalties, the east African nation escaped a penalty last month by agreeing to spend $25 million over the following five years to fight dope.
Ababu Namwamba, Kenya's minister of sports, said that the country would make doping in athletics a crime to stop a run of incidents.