Peptide & Experimental

Ivermectin

Antiparasitic agent (avermectin) · Scabioral, Ivermectin-ratiopharm

Ivermectin is one of the great success stories of medicine: the discovery of the avermectins was awarded the Nobel Prize in 2015 because it pushed back river blindness and lymphatic filariasis worldwide. In Germany, ivermectin is approved against scabies and threadworms. Against Covid-19 it was tested thoroughly in three large randomized trials and brought no relevant benefit. For cancer and longevity there are so far only laboratory data.

What ivermectin is

Ivermectin is a derivative of the avermectins, which the microbiologist Satoshi Ōmura isolated from a soil bacterium and William C. Campbell developed as an agent against parasites. In 2015 the Nobel Assembly wrote that avermectin derivatives had “radically” reduced river blindness and lymphatic filariasis, diseases that affect hundreds of millions of people.

That such a proven, cheap drug might also help against other diseases is an obvious hope. That is exactly why ivermectin was tested in large trials during the pandemic, and why it is worth looking closely at the results.

How it works

Ivermectin binds to glutamate-gated chloride channels in nerve and muscle cells of invertebrates. The increased chloride influx paralyzes the parasites, and they die. According to the summary of product characteristics, ivermectin can also interact with other chloride channels, for example at the receptor of the messenger substance GABA.

In the laboratory, ivermectin also inhibits the replication of viruses and the growth of cancer cells. Whether the concentrations required for this are reached in humans and whether a clinical benefit follows from it is a separate question, and only studies in humans can answer it.

What is well supported

It is a Nobel Prize-winning antiparasitic drug. The avermectins and their derivatives have greatly reduced river blindness and lymphatic filariasis worldwide and are effective against a growing number of other parasitic diseases. For this, Campbell and Ōmura received the 2015 Nobel Prize in Physiology or Medicine.
It is approved in Germany. As a tablet, ivermectin is approved against gastrointestinal strongyloidiasis, against microfilaremia in lymphatic filariasis and against scabies. According to the summary of product characteristics, a single administration of 200 micrograms per kg of body weight is usually recommended.
The Covid question was tested thoroughly. Three large randomized trials with more than 10,000 participants in total studied ivermectin in Covid-19, two of them double-blind and placebo-controlled.
It was well tolerated in the trials. In TOGETHER and ACTIV-6, side effects and serious events did not occur more often under ivermectin than under placebo; in PRINCIPLE there were three serious events under ivermectin and five under usual care.

What the studies show

TOGETHER 2022: hospital admissions in Brazil

The double-blind platform trial TOGETHER gave adults with early, symptomatic Covid-19 and at least one risk factor 400 micrograms per kg of ivermectin or placebo for 3 days. Hospital admission or prolonged emergency department observation occurred in 14.7 versus 16.3 percent (relative risk 0.90, credible interval 0.70 to 1.16). There was no effect even among participants who had taken all tablets.

ACTIV-6 2022: recovery time in the US

1,591 adults with mild to moderate Covid-19 received ivermectin or placebo for 3 days. The median time to sustained recovery was 12 versus 13 days, with no statistically established difference. Hospitalization or death: 1.2 percent each. The authors conclude that the data do not support use in mild to moderate Covid-19.

PRINCIPLE 2024: the largest trial

The British trial PRINCIPLE randomized 8,811 people in primary care, 2,157 of them to ivermectin. Self-reported recovery came on average about 2 days earlier, but the probability of an effect predefined as relevant was only 0.19. Hospital admissions and deaths did not differ, nor did recovery at 3, 6 and 12 months. The authors consider further trials in vaccinated people unjustified.

Cochrane 2022: what remains after rigorous review

The Cochrane review included only prospectively registered randomized trials and in doing so removed 7 of the 14 studies of the previous version. In the remaining 11 studies with 3,409 participants, ivermectin probably had little or no effect on mortality in mild Covid-19 (RR 0.77; 0.47 to 1.25) and none on quality of life.

Cancer: laboratory findings, a retracted cohort, ongoing early-phase trials

In cell lines, ivermectin inhibits the growth of various cancer types. A review of gynecological tumors notes that the data are limited to cell lines (Mujumdar 2025). An observational cohort of 197 cancer patients who received ivermectin and mebendazole via a US telemedicine platform and reported on their own course was retracted in 2026. A controlled phase 1/2 trial combines ivermectin with immunotherapy in metastatic triple-negative breast cancer and is currently recruiting.

Where the data stop

A benefit against Covid-19. Three large randomized trials and a Cochrane review found no relevant effect on hospital admissions, death or long-term recovery.
A benefit against cancer. There is no completed controlled study in humans. Laboratory findings show that an agent affects cells, not that it helps people with cancer.
An effect on longevity. There are no data on a life-extending effect in humans.
The safety of high long-term doses. The single dose against parasites is approved and well documented. For repeated or high doses over weeks and months, safety data are lacking.

Status, approval and legal

Ivermectin is prescription-only in Germany. As a tablet it is approved against gastrointestinal strongyloidiasis, against microfilaremia in lymphatic filariasis caused by Wuchereria bancrofti and against scabies when the diagnosis has been confirmed clinically or parasitologically. The approved dose is usually a single administration of 200 micrograms per kg of body weight.

Use against Covid-19, cancer or for life extension is not approved. Veterinary medicines containing ivermectin are not intended for humans; the summary of product characteristics describes poisonings after accidental ingestion of such preparations.

Safety

In the approved single dose, ivermectin is considered well tolerated, and in the large Covid trials side effects did not occur more often than under placebo. According to the summary of product characteristics, infection with the threadworm Loa loa is important: with very large numbers of microfilariae in the blood, severe brain reactions (encephalopathy) rarely occurred. When the parasites die off, itching, rash, joint and muscle pain are possible.

For overdose, the summary of product characteristics describes impaired consciousness and coma, and after accidental ingestion of veterinary medicines also seizures, balance disorders and shortness of breath. For the high and repeated doses circulating in cancer and longevity circles, there are no safety data.

BK-Score Well studied – effect not confirmed

Human evidence		8
Mechanism		6
Safety data		8
Hype gap		2
Track record of use		10

Evidence 8, because the advertised Covid effect was tested in three large randomized trials – TOGETHER with 1,358 patients comparing ivermectin with placebo, ACTIV-6 with 1,591 and PRINCIPLE with 8,811 participants – and none of them found a relevant effect on hospital admissions or recovery, while for cancer and longevity there are only laboratory data. Mechanism 6, because the antiparasitic effect via chloride channels of invertebrates is well understood, but the antiviral and anticancer effects have only been shown in cell cultures. Safety 8, because the approved single dose has been documented for decades and in mass treatments and was recorded in a placebo-controlled way in the Covid trials; for high long-term doses, such as those circulating for cancer, safety data are lacking. Hype 2, because ivermectin is promoted as a remedy against Covid-19, cancer and aging without any controlled study showing a clinical benefit. Use 10, because avermectins have been used worldwide against parasites for decades. Direction negative: for the advertised Covid effect it is well studied that it does not occur; the benefit within the approved indications remains unaffected by this.

The score rates the state of knowledge, not the substance. “Safety data 9” means well studied – not harmless. “Track record of use 9” means used long and widely – that is not proof of efficacy.
Subjective assessment by Biohacking Kompakt based on published scoring rules – not a scientific rating and not a medical recommendation. Rules and all ratings (German)

Frequently asked questions about ivermectin

What is ivermectin approved for?

In Germany, for gastrointestinal strongyloidiasis, for microfilaremia in lymphatic filariasis and for scabies. The approved dose is usually a single administration of 200 micrograms per kg of body weight. Ivermectin is prescription-only.

What was the Nobel Prize awarded for?

William C. Campbell and Satoshi Ōmura received the 2015 Nobel Prize in Physiology or Medicine for the discovery of the avermectins. Their derivatives, including ivermectin, have greatly reduced river blindness and lymphatic filariasis worldwide.

Does ivermectin help against Covid-19?

No, not to a relevant extent according to current data. Three large randomized trials, TOGETHER, ACTIV-6 and PRINCIPLE, found no effect on hospital admissions or death. In PRINCIPLE, self-reported recovery came about 2 days earlier, which was below the prespecified threshold for a relevant effect.

Does ivermectin work against cancer?

That is not established. In the laboratory, ivermectin inhibits the growth of cancer cells; there is no completed controlled study in humans. A widely cited user cohort was retracted in 2026; a controlled early-phase trial in breast cancer is underway.

Why did early studies show a benefit in Covid-19?

The 2022 Cochrane review excluded 7 of 14 previously included studies because they were not preregistered or not randomized. In the remaining, methodologically more robust studies, there was little or no effect on mortality.

Is ivermectin dangerous?

In the approved single dose it is well tolerated. For overdose, the summary of product characteristics describes impaired consciousness and coma, and after veterinary products also seizures. For high long-term doses, such as those circulating for cancer, safety data are lacking.

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Information only, not medical advice and not a usage or dosage recommendation. Prescription-only and unapproved substances belong in the hands of a physician. Last updated: 2026-10-07.