I have a friend that waited a long time to get married, He finally met his wife. Shortly after they were married, it was apparent that it would be medically impossible for them to have children. (without going into details). They went to many Doctors to see if they could help and everyone told them, impossible.
They spent many nights crying to Hashem. Finally around Lag B’omer they tried Chai Rotel and a year later she gave birth to a boy. Now the boy will have his bar mitzvah soon.
I believe it works!