http://www.medications.com/effect/view/37437 I got a Kenalog injection a few months ago for severe allergies. My period showed up a week earlier than it should have, and I have now been bleeding heavily for over a month. Nobody at my doctor's office warned me of this side effect. I need to make an Sat, 03 Jan 2009 20:59:34 -0500 http://www.medications.com/effect/view/37437?item=15686 Sorry about the side effects. My pharmacist told me kenalog when injected stays in your system at least six months and up to a year. http://www.medications.com/effect/view/37437?item=15686