Ivermectin dosage for humans: two weight tables
U.S. Stromectol oral tablets are 3 mg. Safety and effectiveness in patients weighing less than 15 kg (about 33 lb) have not been established, so the labeled bands start at 15 kg. Charts below show kilograms and approximate pounds for U.S. readers who know their weight in lb.
Strongyloidiasis (~200 mcg/kg, single oral dose)
| Body weight | Approx. lb | Number of 3 mg tablets |
|---|---|---|
| 15–24 kg | 33–53 lb | 1 |
| 25–35 kg | 55–77 lb | 2 |
| 36–50 kg | 79–110 lb | 3 |
| 51–65 kg | 112–143 lb | 4 |
| 66–79 kg | 145–174 lb | 5 |
| ≥80 kg | ≥176 lb | calculate 200 mcg/kg |
For adults at or above 80 kg (≥176 lb), the label leaves a fixed row and you calculate 200 mcg/kg. Example only: 90 kg (about 198 lb) × 200 mcg/kg = 18 mg, which is six 3 mg tablets if the clinician rounds that way—confirm the written count on your prescription.
Onchocerciasis (~150 mcg/kg)
| Body weight | Approx. lb | Number of 3 mg tablets |
|---|---|---|
| 15–25 kg | 33–55 lb | 1 |
| 26–44 kg | 57–97 lb | 2 |
| 45–64 kg | 99–141 lb | 3 |
| 65–84 kg | 143–185 lb | 4 |
| ≥85 kg | ≥187 lb | calculate 150 mcg/kg |
A 70 kg (about 154 lb) adult is often five tablets on the strongyloides table and four on the onchocerciasis table—same person, different job. In mass programs onchocerciasis retreatment is commonly yearly; for an individual patient the label allows intervals as short as three months. Stromectol does not kill adult Onchocerca, so follow-up and retreatment are usually part of the plan. Strongyloidiasis often needs stool checks after the single dose to confirm clearance.
How you take ivermectin
Take the tablets on an empty stomach with water. That instruction protects you from an unpredictably high level: in studied volunteers, a high-fat meal raised bioavailability about 2.5-fold versus fasting. After oral dosing, plasma concentrations rise roughly with dose; mean peak after a 12 mg fasting dose arrives around four hours; the plasma half-life is approximately 18 hours. Metabolism is chiefly hepatic CYP3A4. Those facts steer food timing and drug lists; they do not invent a viral schedule.
If your clinician prescribed oral ivermectin for scabies (off-label relative to this Stromectol indication list), follow the food instruction on that slip. CDC clinical care for classic scabies uses about 200 mcg/kg with food, usually as two doses about 7 to 14 days apart, because a single dose does not clear every mite generation the way a labeled strongyloides day does. Do not blend that with the empty-stomach rule for the approved worm tables above.
Ivermectin side effects
Rates depend on which infection you are treating.
In four strongyloidiasis studies (109 patients given one or two doses of 170–200 mcg/kg), related reactions included dizziness (2.8%) and pruritus (2.8%). Nausea and diarrhea each appeared in 1.8%. The Mazzotti-type and eye reactions of onchocerciasis treatment are not expected in strongyloidiasis.
In onchocerciasis trials (963 adults, 100–200 mcg/kg), worsening Mazzotti-type findings in the first four days included pruritus (27.5%), skin involvement with edema or urticarial rash (22.7%), and fever (22.6%). Lymph-node tenderness and joint symptoms also rose. Facial or peripheral edema, orthostatic hypotension, and tachycardia appeared among drug-related clinical events in ≥1%.
Neurotoxicity—including altered consciousness, confusion, disorientation, and death—has been reported with recommended doses and with overdosage, including in people without onchocerciasis. Seek urgent care for seizures, inability to stand, marked confusion, or breathing trouble. Hypersensitivity to any component of the product is the labeled contraindication.
Pregnancy, warfarin, and Loa loa
Ivermectin should not be used during pregnancy since safety in pregnancy has not been established. It is excreted in human milk in low concentrations; treat a nursing mother only when the risk of delaying her therapy outweighs possible risk to the newborn.
Post-marketing reports have rarely noted an increased INR when ivermectin was co-administered with warfarin—tell the clinician who manages your anticoagulant before the dose.
Rarely, people with onchocerciasis who are also heavily infected with Loa loa have developed serious or fatal encephalopathy after microfilaricidal treatment. If you warrant ivermectin for any reason and have had significant exposure to Loa loa–endemic West or Central Africa, pretreatment assessment for loiasis and careful follow-up belong in the plan.
Immunocompromised patients with intestinal strongyloidiasis may need repeated courses; cure is not always achievable, and the label notes that optimal regimens are not well defined by controlled trials.
A 6 mg tablet and livestock paste
FDA-approved U.S. oral ivermectin now includes 3 mg and 6 mg tablets (for example, a January 2025 ANDA listing both strengths). The Stromectol weight tables above still count 3 mg tablets. If your bottle is 6 mg, do not take the 3 mg tablet count using 6 mg pills—each 6 mg tablet is double the strength, which would double your dose. Confirm the strength on the label and the tablet count your clinician wrote.
Veterinary pastes, pour-ons, and drenches are formulated for animals. Accidental human exposure has produced rash, edema, headache, dizziness, weakness, nausea, vomiting, and diarrhea; seizures, ataxia, and dyspnea are among other reported effects. If someone swallows a livestock product, call America's Poison Centers (Poison Help) at 1-800-222-1222 (or local emergency services for severe symptoms) and keep the container. That is not a substitute for a human prescription count.
COVID-19 is not on the oral Stromectol indication list, and this page does not invent a COVID milligram schedule. Authorization status and outpatient trial endpoints are covered in the ivermectin COVID myths review.
FAQ
What is the ivermectin dosage for humans?
For labeled oral Stromectol use, strongyloidiasis is about 200 mcg/kg once; onchocerciasis is about 150 mcg/kg. You convert that rate into a count of 3 mg tablets from the weight band for that infection.
How many 3 mg tablets do I take?
Use the strongyloidiasis or onchocerciasis table that matches the diagnosis. At or above 80 kg / 176 lb (strongyloides) or 85 kg / 187 lb (onchocerciasis), the label switches to a calculated mcg/kg dose rather than a fixed tablet row.
How do you take ivermectin?
For those approved uses: empty stomach with water. A fatty meal can roughly 2.5× absorption versus fasting. Scabies courses, when prescribed, often follow CDC with-food, two-dose timing instead.
What are common ivermectin side effects?
After strongyloidiasis doses, dizziness and itching were each about 2.8% in studied patients. Onchocerciasis treatment can trigger much higher short-term Mazzotti-type rates (itching about 27.5%, fever about 22.6% in the labeled trials).
Can you take ivermectin while pregnant?
No—the label says it should not be used during pregnancy because safety has not been established.
Is there a 6 mg ivermectin tablet?
Yes—some FDA-approved U.S. generics list 3 mg and 6 mg. The charts on this page count 3 mg tablets; using a 3 mg row count with 6 mg pills would double the milligram dose.
What if someone swallows horse paste?
Treat it as a poisoning risk, not a DIY human dose. Call Poison Help at 1-800-222-1222 and bring the product packaging.
Next step
Weigh yourself, match the infection to one table, and take the approved dose on an empty stomach with water unless your scabies prescription says with food. If the question is whether the drug treats a virus, use the COVID page rather than a higher milligram guess.