No they don't. They use plant oestrogen - I think they hope that unsuspecting folk see the word oestrogen and think, 'Hey, thats what helps breast tissue grow'. Well maybe it does in human form but in plant form? When was the last time you saw a well-stacked plant?
Unless you go surgical, your only possible option is to research Brava breast enhamcing bra which uses vaccuum I think to plump everything up.