Amal round blue pill with only "SP" engraved on one side. No numbers or lines. Just the letters and only on one side ## Hi Hadley, I located a small round blue pill with an italicized SP engraving on one side, which turned out to be the logo for "Schering Plough". Apparently there have been previous reports of this pill suggesting that it contains 5mgs of Aerius (desloratadine); an antihistamine used for allergies and hay fever. If you run a search on google images for "Aerius (desloratadine 5 mg) SP" and scroll down a bit, there should be a few different pill images that accurately portray what it's supposed to look like. Please post back if you think your pill might be something else.