The man was found unconscious and unresponsive in a 42nd-floor apartment around 9:30 a.m.
He was pronounced dead at around 10:15 a.m.
The medical examiner will determine the cause of death, although it appears to be an overdose.
Frankel, founder of Skinnygirl Cocktails and reality TV star who appeared on "Real Housewives" among other shows, has not commented on the death.