A year later he joined Hertha BSC, where he spent a season playing in the reserve team in the Regionalliga Nord, before making the short journey to his hometown, Potsdam, to sign for SV Babelsberg of the same division.
Despite Babelsberg's promotion, Frahn opted to stay in the fourth tier, signing for big-spending RB Leipzig along with strike partner Stefan Kutschke.
In the 2012–13 season, RB Leipzig entered the re-formed Regionalliga Nordost, and won the division unbeaten, with Frahn again finishing as top scorer with 20 goals.
Frahn ended the season as the league's secondtop scorer with 19 goals, behind SV Darmstadt 98's Dominik Stroh-Engel, as the Red Bulls were promoted to the 2.
[4] On 5 August 2019, Chemnitz terminated Frahn's contract with the club after accusing the player of “openly displaying” his sympathy for neo-Nazi groups.