Research chemist Barnaby Fulton works on a fountain of youth pill for a chemical company. One of the labs chimps gets loose in the laboratory and mixes chemicals, but then pours the mix into the water cooler. When trying one of his own samples, washed down with water from the cooler, Fulton begins to act just like a twenty-year-old and believes his potion is working. Soon his wife and boss are also behaving like children.
Cary Grant
as Barnaby Fulton
Ginger Rogers
as Edwina Fulton
Charles Coburn
as Oliver Oxley
Marilyn Monroe
as Lois Laurel
Hugh Marlowe
as Hank Entwhistle
Henri Letondal
as Jerome Kitzel
Robert Cornthwaite
as Dr. Zoldeck
Larry Keating
as G.J. Culverly
Douglas Spencer
as Dr. Brunner
Esther Dale
as Mrs. Rhinelander
George Winslow
as Little Indian
Marjorie Holliday
as Oxley Receptionist (uncredited)
