The legality of buying fish antibiotics like Zithromax (azithromycin) online in the U.S. exists in a gray area. Technically, it is legal to purchase antibiotics labeled and marketed for aquarium or veterinary use without a prescription. That’s why many online retailers can legally sell "fish antibiotics" such as Fish Zithro (fish-grade azithromycin). These products are intended solely for use in ornamental fish, not humans.
Спорт-вики — википедия научного бодибилдинга
