To say these Mexican nationals are “donating” their plasma is a bit of a misnomer. For each hour-long session, “donors” receive a gift card of around USD 50. At most, they can earn around USD 400 monthly, that is, if they wait in line to donate the maximum of two times each week. (Though, if you’re “feeling lucky,” Grifols recently began offering scratchcards with a potential “instant $30 BONUS” for visiting donors.) It would be more accurate to term this plasma selling. But legally, plasma companies classify their payments as “gifts” for those volunteering their time, skirting the law that bars visitor-visa holders from working in the United States. These “gifts” are essential to what has become a multibillion-dollar industry. Driven largely by the growing numbers of aging nonworkers in Western countries, demand for “longevity” medicine has surged, fueling interest in stretching plasma’s already extensive therapeutic capabilities.