Eltroxin is generic alternative to Synthroid.abr Eltroxin is a synthetic form of thyroid hormone (or thyroxine), the hormone normally secreted by the follicular cells of the thyroid gland. It is used to treat thyroid hormone deficiency, and occasionally to prevent the recurrence of thyroid cancer.br br AllDayChemist.com is a professionally managed generic drugs distributor, supplying generic drugs and formulations to patients around the world. We offer great-value generics, without ever compromising on quality.