hi do you mind if i ask how old you are and if youve already had a child as i really would suggest thinking about a mirena coil instead of the injection. that is probably what is causing the sweating, as does the implant in the arm as my sis has just found out after having hers done a few wks ago. i had the injection when my second child was 8 wks old. i weighed nearly 13st when he was due (he weighed 10lb 10ozs at birth!) and was down to 10 1/2 st by the time i got the 1st injection, by the time the second injection was due to run out i was nearly 12 1/2 stone. not good!! it was the injection that made me pile on the weight, straight away gave up the jab and went back to my trusty coil, its a hard slog but im only just now getting back to a weight m happy with. if your over 21 i would seriously consider the coil, its there for 5 yrs unless you decide to have a baby and your periods are so easy to deal with as they are so light and painless. quick simple and trustworthy!