Old black and white movie title?

Question

Here's what I remember...2 Scientists come up with a formula that when they take it they act like children. Two main characters and one was a blonde. I thought it might be Grace Kelly but I can't seem to prove that. Any help would be appreciated.

Answer 1

Let me try a guess: "Monkey business" with Cary Grant, Marilyn Monroe and Ginger Rogers. Check it out at http://www.imdb.com/title/tt0044916/

Good luck!
Cheers,

Answer 2

It is Cary Grant and Ginger Rogers. The movie is called Monkey Business