A note from the reproductive hormonal side.  Long-acting contraceptives, represented primarily by depo-prover, mirena or skyla IUD, and the nexplanon skin implant, all represent progesterone only contraceptives.  While highly effective at preventing pregnancy, all these agents suppress estrogen which is a bad thing.  From puberty to age 30 women are adding bone to maximize to normal bone density.  Lack of estrogen is detrimental to this process.  We are seeing in our practice, if one has the genetic predisposition for Insulin Resistance, low estrogen will accelerate chronic disease including rapid weight gain.  We also see low estrogen causing brain dysfunction including attention deficit, memory, anxiety, depression, migraine headaches, mood changes, night sweats and sleep disturbance etc., all of which are not good for the teen who is in school trying to learn.  In our experience, birth control pills cause a similar phenomenon in many patients.  It is our suggestion that we should be supplementing estrogen for women on these methods of birth control to avoid these side effects.