I got red lumps too when I started on Levemir . I dont know if it's got anything do do with it , but when I started to inject deeper I didn't seem to get them as often I also deliver it much slower as it stings if I inject it too fast, this happend with the Lantus I was on too, but the design of the pens meant it shot in really fast , that used to really hurt. So I much prefer the Levemir pens because I can controll the speed of delivery and it's less painful, its worth a few lumps every now and then . The leaflet says that (side effects reported commonly), redness, swelling, inflamation, itching and bruising at the injection site may occur and that these usually dissapear after a few weeks and that if they dont then to go and see GP , so if you have been on it for longer than this you may have to go back and tell them.