Bad Papa (2018)

Both Male Leads take a pill (drug) that enhances their abilities...
Vivid Romance is about a guy who’s struggling with his police exam, and take a pill in a human drug testing place, has no side effects and become really smart and fit.
Bad papa is similar in the way that the male lead also take a human drug test and has no side effects from the pill but instead of becoming smart he come strong.

Both are about loving dads, who were former boxers. Both met unfortunate circumstances and eventually went back to the boxing/MMA life to support their daughter.