With microplastics found nearly everywhere, fears abound about how they affect our health, given that these materials are designated as “forever plastics”—as in, they never leave our environment or bodies. One start-up in the UK is capitalizing on those concerns by offering a procedure they claim cleans people’s blood: In a 2-hour process, blood is drawn, the plasma is filtered, mixed back with blood cells and then pumped back into the patient, processing between 50 to 80 percent of the blood plasma volume. Patient motivations range from fatigue and long Covid to a desire to conceive; the company’s target demographic is wealthy individuals concerned about their health. But since the science is still unresolved about microplastics’ health impact, how worthwhile is this expensive procedure?