I think the original poster was asking about a product made by BRL Sports (https://brlsports.com/pages/epo-boost) called EPO-Boost. It’s a legal echinacea and iron supplement that they say can increase red blood cells. Erythropoietin is a hormone naturally produced by your kidneys. This product is marketed as a supplement that helps the body create more without taking illegal drugs.
I think most posters probably assumed that the OP was asking about the synthetic EPO that dopers inject.