Ivermectin is an antiparasitic medicine. It has been used for decades to treat certain worm infections, and it has saved millions of people from river blindness. It also became one of the most searched medicines during the COVID-19 pandemic. This guide explains what ivermectin does and doesn’t do, based on the evidence.
What ivermectin is approved to treat
In the US, ivermectin comes in three forms, each for different conditions:
- Tablets (prescription): approved for strongyloidiasis (a threadworm infection of the intestine) and onchocerciasis (river blindness). Doctors also prescribe them for some other parasitic infections, including scabies, particularly severe (crusted) scabies.
- 0.5% lotion (Sklice, over the counter): for head lice in adults and children aged 6 months and over. See our guide to head lice treatment.
- 1% cream (Soolantra, prescription): for the bumps and spots of rosacea.
How ivermectin tablets are taken
- A doctor works out the dose from your body weight. It is often a single dose, sometimes repeated.
- Tablets are taken on an empty stomach with water.
- Depending on the infection, you may need follow-up stool tests to check the treatment worked.
Because the right dose and the need for a repeat dose depend on the infection and on your weight, ivermectin tablets need a prescription and a diagnosis.
What about COVID-19?
Several large randomised trials, including ACTIV-6, TOGETHER and PRINCIPLE, tested ivermectin in people with COVID-19. They found it did not speed up recovery or reduce hospital admissions compared with a placebo. The FDA has not authorised or approved ivermectin to prevent or treat COVID-19.
Never use animal ivermectin
Ivermectin products for horses, cattle and dogs are much more concentrated and are made for animals that weigh far more than a person. US poison centres have reported people needing hospital treatment after taking them, with confusion, seizures, very low blood pressure and coma. Never take a veterinary product.
Check with a doctor first if you
- are pregnant or breastfeeding
- have liver disease
- take warfarin or other regular medicines
- have lived in or travelled to Central or West Africa. Ivermectin can cause serious reactions in people with a heavy Loa loa (eye worm) infection, so doctors test for it first.
- want to treat a child who weighs less than 15 kg (33 lb)
Side effects
Most people have no side effects or mild ones such as dizziness, nausea or itching. Read our full guide to ivermectin side effects, interactions and overdose warning signs.
More in our Lice and Parasites guide: all our articles on this topic in one place.
This article is for general information only and isn’t a substitute for advice from a doctor or pharmacist. Always read the label before using any medicine.
