Banned worldwide after its notorious branding as the culprit behind a generation of babies with "flipper hands" and other birth defects, thalidomide has multitasked its way back into favor in recent years -- not least as a powerful treatment for apthous ulcers (way-bad chancre sores), wasting, diarrhea and Kaposi's sarcoma (KS) in HIVers. But how much is too much of a once-bad, now-good thing? A two-month study testing different doses of thalidomide in HIVers with 200 to 500 CD4 cells found that two out of 36 had serious side effects at 150 mg daily, while those taking 50 to 100 mg tolerated it just fine, thank you. (Not surprisingly, the lower your CD4s, the yuckier the reaction.) The sedative, once prescribed for morning sickness but now used against cancer as well as inflammatory and auto-immune disorders, didn't seem to pump up viral loads, either. And for what study leader David Wohl, MD, called "a drug with a checkered past," that's something to, uh, quack about.