Hi, thanks for posting your query Acne starts during puberty as a result of hormone production by the ovaries The androgens produced stimulate the oil glands (maximum on face , upper back and chest) to produce more of oil which collects in the gland ducts and clogs the pores, this leads to black heads and white heads. The bacteria which live in the ducts utilize the oil to produce free fatty acids which spill out within the skin , irritates the structures leading to raised bumps which may be pus filled pimples SO acne occurs on and off due to hormones and can occur till hormones are produced. normally acne decreases by 30-40 years but even seen later than this. There is no exact corelation with diet Unwated 72 is an emergency contraceptive, not to be used as regular birth control method, has only progeterone is unlikely to cause acne hope this answers your query