The Athletics Integrity Unit announced that Okagbare had "tested positive for human growth hormone" in an out-of-competition test on July 19.
That resulted in a mandatory suspension, coming on the day that Okagbare was due to race against Great Britain s Dina Asher-Smith in their semi-final in Tokyo.
Okagbare finished first in her heat for the women's 100m on Friday, recording a time of 11.05 seconds to beat Britain's Asha Philip and Tynia Gaither of the Bahamas.
That put the 32-year-old into a third consecutive Olympic semi-final.
Okagbare, who won Olympic silver in the long jump in Beijing 13 years ago, holds the Commonwealth Games record in the women's 100 metres, set in Glasgow in 2014.
The women’s 100m final is scheduled to run at 1.50pm on Saturday.