What is Ivermectin?
Ivermectin is a macrocyclic lactone antiparasitic derived through fermentation from the soil bacterium Streptomyces avermitilis. It acts against a wide range of parasites including roundworms (nematodes) and arthropods. Ivermectin is used to treat onchocerciasis (river blindness), strongyloidiasis and scabies.
Research examines its effects against various parasitic diseases. This information is for research and educational purposes only. No medical advice.
How it works
Ivermectin binds tightly to glutamate-gated chloride channels in the nerve and muscle cells of parasites and opens them (Chen & Kubo, 2018; US prescribing information). This results in:
- Chloride flowing into the nerve and muscle cells
- Paralysis of parasite muscle
- Loss of parasite reactivity and motility
- Lethal effect on parasites
Ivermectin also acts on other ion channels, for example GABA-gated chloride channels, but that is not the main route. According to the prescribing information, the selectivity for parasites comes from the fact that mammals largely lack such glutamate-gated chloride channels, ivermectin binds only weakly to their other chloride channels and in humans it hardly crosses the blood-brain barrier.
Where it acts
Where ivermectin acted in studies
Tap a point or a card. Colour = chloride channel of the parasites, grey = observed in studies.
- Gut
Threadworm: cleared 1.79 times as often as with albendazole2
GluCl - Skin
Scabies after mass treatment from 32.1 to 1.9 percent3
GluCl - Blood
Mosquitoes that bit treated people died as in the lab test9
Observed in trials - Nervous system
In healthy adults no signs of an effect up to ten times the highest approved dose4
Observed in trials - Airways (COVID-19)
No fewer hospital admissions than on placebo6
Observed in trials
Targets in the ChEMBL database12
Compound CHEMBL6067487: one recorded mechanism, Modulator, direct binding.
- Gene
- GluClX
- UniProt
- Q25634
- ChEMBL
- CHEMBL2363051
- Action
- Modulator, direct binding
Administration and dosing
Dosing
Dosing, titration and syringe
Loading the dosing information …
- Getting started and stepping up, drawn as a staircase
- Units on the U-100 syringe for every step
- How long one vial lasts
What the research shows
Clinical trials indicate that ivermectin:
- Is highly effective against Onchocerca volvulus
- Eliminates Strongyloides stercoralis infections
- Is effective for scabies treatment
- Shows different efficacy profiles at various dosages
- Exhibits dose-dependent relationship in severe parasitic burdens
- Enables broad activity against arthropods
Meta-analyses clarify that higher doses or multiple administrations may be necessary for complex parasitic infections.
Study results
What the trials measured
Interactive: switch tabs, tap points, show or hide arms. Arms are named relative to each other, no dosing advice.
Scabies in three island communities3
Share of people with scabies, 2,051 participants
Standard care (permethrin for those affected): Month 0 +36.6%, Month 12 +18.8%. Permethrin for everyone: Month 0 +41.7%, Month 12 +15.8%. Ivermectin: Month 0 +32.1%, Month 12 +1.9%.
Each community received one approach. With ivermectin prevalence fell by 94 percent relative, with permethrin for everyone by 62 percent, with standard care by 49 percent.
Impetigo in the same communities3
Share of people with a pus-forming skin infection
Standard care (permethrin for those affected): Month 0 +21.4%, Month 12 +14.6%. Permethrin for everyone: Month 0 +24.6%, Month 12 +11.4%. Ivermectin: Month 0 +24.6%, Month 12 +8.0%.
Impetigo often follows scabies. Prevalence fell by 67 percent relative with ivermectin, 54 percent with permethrin for everyone and 32 percent with standard care.
Ivermectin versus other worm drugs2
Relative risk, 7 trials with 1,147 participants, above 1 = more often with ivermectin
Cochrane review, low to moderate quality evidence. Against albendazole the worm was cleared more often with ivermectin, against thiabendazole about as often with fewer side effects. No serious side effects or deaths were reported.
Research status
Where the research stands
Ivermectin has been approved since 1996. On ClinicalTrials.gov 241 trials list ivermectin. Shown are registered trials on scabies, worm infections and malaria. The scabies trial from Fiji is listed in the Australian registry. As of 26 Oct 2026. 10
- Preclinical Discovery from a soil bacterium, target: chloride channels of parasites
- Phase 1 no registered trial
- Phase 2 1 trial, 1 completed
- Phase 3 5 trials, 4 completed
- Approval since 1996 according to ChEMBL
Show all 6 phase 2 and 3 trials on a timelineHide timeline
IVERMAL · NCT02511353 · 141 participants, started Jul 2015, primary endpoint reached Jul 2016. Tests several agents.
Registry entry ↗ · Results: Smit et al., Clinical Infectious Diseases, 2019, DOI 10.1093/cid/ciy1063
NCT00790998 · 1,497 participants, started Apr 2009, primary endpoint reached Feb 2012. Tests several agents.
Registry entry ↗ · Results not yet in PubMed
STRONGTREAT · NCT01570504 · 312 participants, started Mar 2013, primary endpoint reached Jun 2018.
Registry entry ↗ · Results not yet in PubMed
SCRATCH · NCT02407782 · 1,092 participants, started Jan 2016, primary endpoint reached Dec 2021. Tests several agents.
Registry entry ↗ · Results not yet in PubMed
RIMDAMAL II · NCT03967054 · 4,124 participants, started Jul 2019, primary endpoint reached Nov 2020.
Registry entry ↗ · Results not yet in PubMed
BOLT · NCT07159373 · 5,100 participants (planned), started Sept 2026, primary endpoint planned Jun 2027. Tests several agents.
Bar: start to primary endpoint (planned for running trials). Green = completed, blue = progress until 26 Oct 2026.
On the skin
Ivermectin has also been studied as a cream for rosacea. In a phase 3 trial with 962 participants the inflammatory skin lesions decreased more with the ivermectin cream than with a metronidazole cream. The skin also tolerated it better (Taieb 2015).
Side effects
Common side effects include:
- Headaches
- Dizziness
- Fatigue
- Gastrointestinal discomfort (nausea, diarrhea)
- Itching (Herxheimer-like reaction from parasite breakdown)
More serious side effects are rare, but neurological symptoms can occur at very high doses. Ivermectin is contraindicated in neurofil arial infections in West Africa without additional monitoring.
Tolerability
Side effects in mass treatment
Out of 100 treated people, in how many a mild side effect occurred, ivermectin versus permethrin for everyone.
| Event | Permethrin for everyone | Ivermectin |
|---|---|---|
| Mild side effects3 | 7% | 16% |
In healthy adults side effects up to ten times the highest approved dose were as common as on placebo. The pupils did not dilate. In threadworm trials dizziness, nausea and disorientation were reported in all groups.342
Storage
Ivermectin tablets should be stored in a dry, cool place, protected from light. Storage temperature should be between 15-25 degrees Celsius. Original containers protect against moisture and light and should remain tightly sealed. Do not refrigerate.
