Pain and bruising after injection of phenergan

Well I don't think Phenegran is normally injected into the arm. The arm muscle is just not big enough for several cc's of this med. If I had to guess, that is probably why your arm is still bruised and sore. Normally that med is given in the hip because it is bigger and can handle it better. Even then you will have maybe a small bruise and knot. But this should go away in a week or two. Your arm may take a little bit longer. I hope this info helps.