The TGA said there had been a significant increase in the number of Ivermectin prescriptions dispensed in recent months, leading to shortages for those who need the medicine for scabies and parasite infections.
"There are a number of significant public health risks associated with taking Ivermectin in an attempt to prevent Covid-19 infection rather than getting vaccinated," the TGA said.
Ivermectin is not approved for use for Covid-19 in Australia or in other developed countries.
Its use by the general public for coronavirus is strongly discouraged by the National Covid-19 Clinical Evidence Taskforce, the World Health Organisation and the United States Food and Drug Administration.
The TGA said it was acting on the advice of the Advisory Committee for Medicines Scheduling to introduce the new restrictions.
But it said certain specialists, including infectious disease physicians, dermatologists, gastroenterologists and hepatologists, will be permitted to prescribe ivermectin for other "unapproved indications" if they "believe it is appropriate for a particular patient".