Well I made the switch over to Heparin from Lovenox yesterday. And all I can say is, it doesn't sting!!! Lovenox burns like hell. It burns going in and afterwards. The hardest part of the Heparin is that the needle seems to be so huge. But I'm sure I will get over that. And I have to fill my syringes, where as the Lovenox came prefilled. But I now know how to properly fill a needle. Oh and the other plus of the Lovenox is that it has a sheath that comes down over the needle after you use it. I just feel so unsafe tossing an exposed needle away, even if it is in the special sharps container.