No, Lisa Kudrow was not on Mad About You before Friends.
Lisa Kudrow joined the cast of Friends in 1994, playing the role of Phoebe Buffay. Mad About You premiered in 1992 and ran for seven seasons, ending in 1999. While Kudrow was not a cast member on Mad About You, she did appear in a guest role on the show in 1995, playing the character of Ursula, Phoebe's identical twin sister.
This appearance was a crossover event between the two shows, as Ursula had already been established as a recurring character on Mad About You before Kudrow's guest spot.
The appearance of Ursula on Mad About You was a fun way to connect the two popular sitcoms and showcase Kudrow's comedic talent. It also highlighted the versatility of the actress, who was able to portray two distinct characters with ease.
