Ivermectin is an antiparasitic medicine. It treats scabies, head lice, river blindness, strongyloidiasis and other parasitic infections, and — as a cream — the inflammatory bumps of rosacea. It is not a treatment for COVID-19, and the evidence on that is now settled.
What is Ivermectin?
The South African Medicine Price Registry lists Soolantra, a Schedule 3 cream containing ivermectin 10 mg/g (1%), for rosacea. Oral ivermectin is used in South Africa for parasitic infections and is obtained on prescription.
Ivermectin comes from avermectins, compounds isolated from a soil bacterium — a discovery that won the 2015 Nobel Prize in Physiology or Medicine, because it transformed the treatment of river blindness and lymphatic filariasis in Africa and elsewhere.
It works by binding to glutamate-gated chloride channels in the nerve and muscle cells of invertebrates. Those channels open, the parasite is paralysed, and it dies. Mammals do not have those channels in accessible tissue, and a barrier in the brain keeps ivermectin out of the central nervous system — which is why a medicine that paralyses parasites is well tolerated by people.
That selectivity has a limit worth knowing: at very high doses the barrier can be overwhelmed, producing neurological toxicity. It is one reason dose matters, and why veterinary formulations — concentrated for large animals — are dangerous in people.
What is Ivermectin commonly used for?
Oral ivermectin:
- Scabies, particularly crusted scabies, widespread infestation, outbreaks in institutions, or where topical treatment has failed. The whole household usually needs treating at the same time, whether or not everyone itches.
- Strongyloidiasis — a roundworm infection that can persist for decades and become life-threatening in anyone given steroids or immunosuppressed. This is an important use.
- Onchocerciasis (river blindness), in mass treatment programmes.
- Lymphatic filariasis, in combination.
- Head lice, as an alternative where topical treatment has failed.
- Other roundworm infections, including some cases of ascariasis.
Topical ivermectin (Soolantra):
- Papulopustular rosacea — the inflammatory bumps and pustules of rosacea. It works both against Demodex mites and through an anti-inflammatory effect, and it is genuinely effective for this.
On COVID-19, since that is what brings many people to this page:
Ivermectin does not treat or prevent COVID-19. Early laboratory work showed activity against the virus in cell culture — but at concentrations far higher than can be achieved safely in a person. Multiple large, well-conducted randomised trials have since found no benefit on recovery, hospitalisation or death. Several influential early studies supporting it were withdrawn for data problems.
That is not a political statement; it is where the evidence landed after it was properly tested. Taking ivermectin for COVID-19 offers no benefit and carries real risk — particularly when people take veterinary formulations or large doses, which has caused hospital admissions for confusion, seizures, low blood pressure and liver injury.
How Ivermectin fits into this medicine category
| Group | Examples | Treats |
|---|---|---|
| Antiparasitics (avermectins) | Ivermectin | Scabies, lice, roundworms, filarial infections; rosacea topically |
| Other antiparasitics | Albendazole, mebendazole, praziquantel | Worms and flukes |
| Topical scabicides | Permethrin, benzyl benzoate | Scabies — usually first-line |
| Antibacterials | Azithromycin (Azrotrin), penicillins | Bacteria — no effect on parasites |
| Antiprotozoals | Metronidazole | Anaerobes, giardia, amoebae; also used in rosacea |
| Antifungals | Clotrimazole, fluconazole | Fungi |
For ordinary scabies, topical permethrin is usually first-line, with oral ivermectin used for crusted or resistant cases and outbreaks. See the antibiotics and antimicrobials hub.
What to check before using Ivermectin
Never use veterinary ivermectin. Products formulated for cattle, horses or sheep are concentrated for animals many times human body weight, and the pastes and injectables contain excipients not intended for people. This has caused serious poisoning and deaths.
Tell your doctor or pharmacist if you:
- Have travelled or lived in Central or West Africa, or where Loa loa is endemic. Treating someone with a heavy Loa loa infection can cause a severe and sometimes fatal brain reaction, so screening comes first in those settings.
- Have liver disease.
- Are immunosuppressed, or on steroids — relevant particularly to strongyloidiasis, which can disseminate catastrophically in that situation.
- Are pregnant or breastfeeding.
- Are treating a young child or someone under 15 kg, where oral ivermectin is generally avoided.
- Take warfarin, or medicines affecting liver enzymes.
Practical points:
- Take oral ivermectin on an empty stomach with water, unless directed otherwise — although absorption is higher with food, standard dosing assumes fasting.
- The dose is by body weight. Be weighed rather than estimating.
- A second dose is often needed a week or two later for scabies, to catch mites hatching from eggs the first dose did not kill.
- Treat the household simultaneously for scabies, and wash bedding and clothing hot and dry on high heat, or seal items in a bag for several days.
- Expect itching to continue for two to four weeks after successful scabies treatment. That is an allergic response to dead mites, not treatment failure — and it is the commonest reason people wrongly conclude it has not worked and re-treat unnecessarily.
- For the rosacea cream: apply a pea-sized amount once daily to the whole face, avoiding eyes and lips, and expect improvement over weeks to months.
Possible cautions and when to ask a pharmacist or doctor
Oral ivermectin at correct doses is generally well tolerated. Common effects are itching, rash, dizziness, nausea, abdominal discomfort, headache and tiredness.
Where a heavy parasite burden is being treated, a reaction to dying parasites can cause fever, swollen glands, joint pain and worsening itch in the first days. That is expected in that context, but should be reported.
The cream commonly causes burning, stinging or dryness at first.
Get emergency help for:
- Confusion, drowsiness, difficulty walking, seizures or loss of consciousness — signs of neurological toxicity, almost always from a large overdose or veterinary product.
- Severe dizziness, fainting or a marked drop in blood pressure.
- Swelling of the face, lips or tongue, difficulty breathing, or a widespread blistering rash.
- Severe headache with neck stiffness or confusion, particularly after treatment in a Loa loa area.
Contact your doctor if:
- Itching persists beyond four to six weeks after scabies treatment, or a new rash appears — that may be re-infestation rather than persistence.
- Scabies keeps returning in a household, which usually means not everyone was treated at once.
- You have abdominal pain, diarrhoea or a cough with a worm infection, which may indicate spread.
- Rosacea is not improving after several months of the cream, or your eyes are affected — ocular rosacea needs separate treatment.
- You are considering ivermectin for anything other than a parasitic infection or rosacea. Speak to a doctor first.
Related medicine guides
Frequently asked questions
What is ivermectin used for? Parasitic infections — scabies, head lice, strongyloidiasis, river blindness and lymphatic filariasis — and, as a cream, the inflammatory bumps of rosacea.
Does ivermectin treat COVID-19? No. Multiple large randomised trials found no benefit on recovery, hospitalisation or death. Early laboratory activity was at concentrations unachievable safely in people.
Is it an antibiotic? No. It is an antiparasitic. It has no effect on bacteria.
Can I use the veterinary version? No. Veterinary products are concentrated for animals many times human weight and contain excipients not meant for people. They have caused serious poisoning and deaths.
Why am I still itching after scabies treatment? Itching commonly continues for two to four weeks as an allergic response to dead mites. That is not treatment failure.
Does everyone at home need treating? For scabies, yes — usually the whole household at the same time, whether or not they itch, plus hot washing of bedding and clothing.
Why a second dose? Ivermectin does not kill mite eggs, so a second dose a week or two later catches newly hatched mites.
What is Soolantra used for? Papulopustular rosacea — the inflammatory bumps and pustules. It is a 1% ivermectin cream applied once daily.