Ivermectin: A Comprehensive Guide to Uses, Dosage, and Safety (2026 Update)

Medical research and pharmaceutical development

What is Ivermectin?
FDA-Approved Uses
How Ivermectin Works
Dosage Guidelines
Latest 2026 Research
Safety Profile & Side Effects
Important Safety Warnings
Global Health Impact
Frequently Asked Questions
References

What is Ivermectin?

Ivermectin is a highly effective antiparasitic medication that has been a cornerstone of global health for over four decades. Discovered in the late 1970s, this medication earned its developers the 2015 Nobel Prize in Physiology or Medicine for its profound impact on treating parasitic diseases affecting millions worldwide.

Key Facts:

Drug Class: Antiparasitic agent (anthelmintic and ectoparasiticide)
Primary Use: Treatment of parasitic infections in humans and animals
FDA Status: Approved for specific parasitic conditions
Availability: Prescription-only in the United States
Forms: Oral tablets, topical cream, topical lotion

Ivermectin works by paralyzing and killing parasites, making it particularly effective against certain worms, mites, and lice. The medication has been distributed billions of times through mass drug administration programs, preventing blindness and disfigurement for millions of people in developing countries.

For a detailed breakdown of all medical applications, see our complete guide to ivermectin uses.

FDA-Approved Uses

The U.S. Food and Drug Administration (FDA) has approved ivermectin for the following human medical conditions:

FDA-Approved Uses of Ivermectin

Intestinal Strongyloidiasis**

Strongyloidiasis is a parasitic infection caused by the roundworm Strongyloides stercoralis. This infection can be particularly dangerous in immunocompromised individuals.

Symptoms include:

Abdominal pain and bloating
Diarrhea or constipation
Skin rashes (larva currens)
Cough and wheezing

Treatment:

Ivermectin tablets (Stromectol®): 200 µg/kg as a single dose
Follow-up stool examinations recommended

Onchocerciasis (River Blindness)**

Onchocerciasis is caused by the parasitic worm Onchocerca volvulus, transmitted through blackfly bites. It's a leading cause of preventable blindness in tropical regions.

Characteristics:

Affects approximately 21 million people globally
Primarily found in sub-Saharan Africa
Can cause severe itching, skin lesions, and vision loss

Treatment:

Ivermectin tablets: 150 µg/kg as a single annual dose
May require repeated annual treatments

Topical Formulations**

Ivermectin Cream (Soolantra®):

Approved for inflammatory lesions of rosacea in adults
Applied once daily to affected areas

Ivermectin Lotion (Sklice®):

Approved for head lice in patients 6 months and older
Single-application treatment

Off-Label Uses

While not FDA-approved for these conditions, ivermectin is sometimes prescribed off-label for:

Scabies (though recent 2026 research suggests permethrin may be more effective)
Other parasitic infections under medical supervision

Learn more about all approved and off-label ivermectin uses.

[!IMPORTANT] Important: Ivermectin should only be used for FDA-approved indications or under the guidance of a qualified healthcare provider. Self-medication can be dangerous.

How Ivermectin Works

Mechanism of Action

Ivermectin belongs to a class of drugs called macrocyclic lactones. It works through a sophisticated mechanism that targets parasites while remaining safe for humans:

Ivermectin Mechanism of Action

Chloride Channel Activation:

Binds to glutamate-gated chloride channels in parasite nerve and muscle cells
Causes increased permeability to chloride ions
Results in hyperpolarization of parasite cells

Paralysis and Death:

Disrupts neurotransmission in parasites
Leads to paralysis and eventual death of the organism
Does not significantly affect mammalian nerve cells

Selective Toxicity:

Parasites lack the blood-brain barrier protection present in mammals
Higher concentrations accumulate in parasite nervous systems
Minimal impact on human neural function at therapeutic doses

Pharmacokinetics

Absorption:

Rapidly absorbed after oral administration
Peak plasma concentrations: 4-5 hours
Fat-containing meals increase absorption by approximately 2.5-fold

Distribution:

Widely distributed in body tissues
High lipophilicity (fat-soluble)
Limited penetration of blood-brain barrier in humans

Metabolism:

Primarily metabolized in the liver
Multiple metabolites formed
Main enzyme: CYP3A4

Elimination:

Half-life: Approximately 18 hours (can range 16-35 hours)
Excretion: Primarily through feces
Less than 1% excreted unchanged in urine

Dosage Guidelines

[!CAUTION] Medical Supervision Required: All ivermectin dosing should be determined by a healthcare provider. The information below is for educational purposes only.

For complete weight-based charts and detailed dosing instructions, visit our ivermectin dosage guide.

Standard Dosing for Approved Indications

Condition	Dosage	Administration	Notes
Strongyloidiasis	200 µg/kg	Single oral dose	Take on empty stomach with water
Onchocerciasis	150 µg/kg	Single annual dose	May need repeated yearly
Head Lice	Topical lotion	Single application	Sufficient to cover dry hair
Rosacea	Topical cream 1%	Once daily	Apply to affected areas

Weight-Based Dosing Chart

For oral ivermectin tablets (3mg tablets):

Body Weight (kg)	Body Weight (lbs)	200 µg/kg Dose	Number of 3mg Tablets
15-24 kg	33-53 lbs	3 mg	1 tablet
25-35 kg	55-77 lbs	6 mg	2 tablets
36-50 kg	79-110 lbs	9 mg	3 tablets
51-65 kg	112-143 lbs	12 mg	4 tablets
66-79 kg	145-174 lbs	15 mg	5 tablets
≥80 kg	≥176 lbs	200 µg/kg	Calculate individually

Special Populations

Pediatric Use:

Safety established in children weighing ≥15 kg
Not recommended for infants less than 15 kg or less than 6 months (except for topical head lice lotion)

Pregnancy:

Category C: Animal studies show adverse effects
Should only be used if clearly needed and benefits outweigh risks
Consult healthcare provider

Elderly:

No specific dose adjustments typically required
Monitor for increased sensitivity

Hepatic Impairment:

Use with caution
May require dose adjustment in severe cases

Renal Impairment:

Minimal renal excretion
No specific dose adjustment typically needed

Latest 2026 Research

Cancer Research

Recent studies in 2026 have explored ivermectin's potential anticancer properties:

Current Evidence:

Preclinical Studies: Laboratory research suggests ivermectin may inhibit cancer cell growth and induce tumor cell death
Ongoing Clinical Trials: A Phase I/II trial (expected completion October 2026) is evaluating ivermectin combined with immunotherapy for metastatic triple-negative breast cancer
Important Limitation: As of early 2026, there is zero real-world clinical evidence that ivermectin alone can cure cancer

[!WARNING] Critical: Ivermectin is NOT approved for cancer treatment. Patients should not substitute proven cancer therapies with ivermectin. Always consult an oncologist for cancer treatment.

Malaria Control

The BOHEMIA trial (published July 2025) demonstrated promising results:

Key Findings:

26% reduction in new malaria infections in children aged 5-15 in Kenya
Supports ivermectin as a complementary tool in malaria control
Particularly valuable given rising insecticide resistance

Scabies Treatment

A significant multicenter randomized clinical trial (January 2026) compared treatments:

Results:

5% permethrin cream showed statistical superiority over oral ivermectin
Higher cure rates for permethrin in both children and adults
Ivermectin non-inferiority not demonstrated

COVID-19

Current Status (2026):

Ivermectin is NOT FDA-approved for COVID-19 treatment or prevention
Systematic review (January 2025): Some symptom benefit but no significant effect on mortality, mechanical ventilation, ICU admissions, or hospitalization
Multiple major health organizations recommend against its use for COVID-19

Safety Profile & Side Effects

For a complete safety profile and all potential adverse reactions, see our detailed ivermectin side effects guide.

Common Side Effects (Generally Mild)

Occurring in greater than 1% of patients:

Dizziness
Nausea
Diarrhea
Fatigue
Abdominal pain
Loss of appetite
Constipation
Weakness
Skin rash or itching

For Onchocerciasis Treatment (Mazzotti Reaction): When treating river blindness, side effects are often related to the dying parasites:

Fever
Itching
Swollen lymph nodes
Joint pain
Eye irritation
Rapid heartbeat

Serious Side Effects (Rare)

Seek immediate medical attention if experiencing:

Severe skin reactions (Stevens-Johnson syndrome, toxic epidermal necrolysis)
Vision changes or eye pain
Severe dizziness or loss of consciousness
Seizures
Severe confusion or altered mental status
Difficulty breathing
Severe abdominal pain

Drug Interactions

Important interactions:

Warfarin: May increase bleeding risk
CYP3A4 Inhibitors (ketoconazole, itraconazole): May increase ivermectin levels
P-glycoprotein Substrates (digoxin): Potential for increased serum levels
Central Nervous System Depressants: May enhance sedative effects

[!IMPORTANT] Always inform your healthcare provider of all medications, supplements, and herbal products you are taking.

Important Safety Warnings

Animal vs. Human Formulations

Critical Distinction:

NEVER use veterinary ivermectin in humans
Animal formulations are:
- Highly concentrated (often 100x human doses)
- May contain inactive ingredients harmful to humans
- Not tested for human safety

Several U.S. states have passed legislation allowing over-the-counter sales, but the FDA strongly recommends prescription-only use under medical supervision.

Special Warnings

Loa loa Infection:

Patients with Loa loa (eye worm) infection risk serious and potentially fatal encephalopathy
Pre-treatment screening recommended in endemic areas

Hepatotoxicity:

Rare cases of liver enzyme elevations reported
Monitor liver function in patients with pre-existing liver disease

Neurological Effects:

Rare cases of encephalopathy, confusion, seizures
Higher risk with co-administered drugs affecting the blood-brain barrier

Global Health Impact

Global Impact of Ivermectin

Mass Drug Administration Programs

Ivermectin has been a cornerstone of global health initiatives:

Statistics:

Over 4 billion doses distributed since 1987
Programs in 33 countries for onchocerciasis control
40 million people treated annually for lymphatic filariasis

Impact:

Prevention of blindness in millions
Reduction of disfigurement from parasitic diseases
Near-elimination of onchocerciasis in several Latin American countries

Nobel Prize Recognition

In 2015, the Nobel Prize in Physiology or Medicine was awarded to:

Satoshi Ōmura: Discovered the bacterium producing avermectin
William C. Campbell: Developed ivermectin from avermectin

The Nobel Committee recognized ivermectin's revolutionary impact on global health, particularly in treating river blindness and lymphatic filariasis.

Donation Programs

Merck's Mectizan® Donation Program:

Started in 1987
Longest-running disease-specific drug donation program
Commits to donate ivermectin for as long as needed
Has provided over 2.7 billion treatments

Frequently Asked Questions

Can I buy ivermectin over the counter?

As of 2026, several U.S. states (Arkansas, Idaho, Louisiana, Tennessee, Texas) have passed legislation allowing OTC sales. However, the FDA recommends obtaining ivermectin only through a prescription from a licensed healthcare provider to ensure appropriate use and dosing.

Is ivermectin effective against COVID-19?

No. Ivermectin is not FDA-approved for COVID-19, and current evidence does not support its use for this condition. Multiple systematic reviews have shown it does not significantly improve important outcomes like mortality or hospitalization.

How long does ivermectin stay in your system?

Ivermectin has a half-life of approximately 18 hours. It typically takes about 5-6 half-lives for a drug to be eliminated from the body, meaning ivermectin is largely cleared within 4-5 days after the last dose.

Can I drink alcohol while taking ivermectin?

While there's no absolute contraindication, alcohol may enhance the sedative effects of ivermectin. It's best to avoid alcohol during treatment and consult your healthcare provider.

Is ivermectin safe during pregnancy?

Ivermectin is Pregnancy Category C. It should only be used during pregnancy if the potential benefit justifies the potential risk to the fetus. Always discuss with your healthcare provider.

Can ivermectin be used for scabies?

While ivermectin is sometimes used off-label for scabies, recent 2026 research suggests that permethrin cream may be more effective. Consult a dermatologist for the most appropriate treatment.

Medical Disclaimer

[!CAUTION] Important Medical Disclaimer: This article is for informational and educational purposes only and is not intended as medical advice. Ivermectin is a prescription medication that should only be used under the supervision of a qualified healthcare provider. Never self-diagnose or self-medicate. Always consult with your doctor or pharmacist before starting, stopping, or changing any medication. If you experience a medical emergency, call 911 or seek immediate medical attention.

Ivermectin Uses Guide - Complete medical applications
Dosage Guidelines - Weight-based dosing charts
Side Effects Profile - Complete safety information

References

FDA. (2024). FDA Approved Drugs: Ivermectin. U.S. Food and Drug Administration. https://www.fda.gov
Drugs.com. (2026). Ivermectin Uses, Dosage & Side Effects. https://www.drugs.com
BMJ. (2026, January). Multicentre randomised clinical trial comparing permethrin cream and oral ivermectin for scabies. British Medical Journal.
University of Oxford. (2025, July). BOHEMIA Trial Results: Ivermectin reduces malaria infections by 26% in Kenyan children.
Onco'Zine. (2026). Ivermectin in Cancer Research: Phase I/II Clinical Trial Update.
Macmillan Cancer Support. (2026). Can ivermectin cure cancer? Current evidence review.
NIH PubMed. (2025, January). Systematic review and meta-analysis of ivermectin for COVID-19: Updated evidence. National Institutes of Health.
Nobel Prize Committee. (2015). The Nobel Prize in Physiology or Medicine 2015: Campbell & Ōmura.
Merck. (2026). Mectizan Donation Program: 2026 Annual Report.
Medscape. (2026). Ivermectin Dosing, Indications, Interactions, Adverse Effects.

Last Updated: January 17, 2026
Author: Dr. Sarah Chen, MD - Board-certified in Infectious Diseases
Reviewed By: Medical Editorial Team

For the latest information on ivermectin, always consult with your healthcare provider or visit the FDA website at www.fda.gov