For adults, ivermectin tablets are dosed by body weight, not by a fixed "one pill for everyone" amount. The FDA-approved labeling for Stromectol (ivermectin) tablets sets a single oral dose of about 200 micrograms per kilogram (mcg/kg) for intestinal strongyloidiasis and about 150 mcg/kg as a single dose for onchocerciasis (river blindness). Because the math turns into whole tablets, the label converts weight into fixed bands, and those bands are the version of the ivermectin dosage a prescriber and pharmacist work from.

Ivermectin is a prescription medicine in most of the United States, and the correct dose depends on the infection being treated, confirmed diagnosis, body weight and other medicines you take. A handful of states have passed laws allowing pharmacy sale without a prescription, and more bills were pending in early 2026 — those details are moving quickly and are covered below. State-law, price and availability facts in this article were last verified on September 26, 2026.

Key takeaways

  • The approved oral dose is weight-based: about 200 mcg/kg once for strongyloidiasis and about 150 mcg/kg once for onchocerciasis, per the FDA label.
  • The 3 mg tablet is the long-standing US strength; 6 mg generic labeling exists on DailyMed, and 12 mg tablets are common outside the US but are not the usual US retail strength.
  • The label directs that tablets be taken on an empty stomach with water.
  • Ivermectin is not FDA-approved for COVID-19, and large randomized trials have not shown meaningful benefit for that use.
  • Ivermectin products labeled for animals — including pastes and injectable livestock products — are approved for animal use only and are not approved for people.
  • This page reports what the approved label says for the two uses the FDA has approved. It does not calculate, suggest, or extrapolate a dose for any other use.

Ivermectin forms and strengths (3 mg, 6 mg, 12 mg)

Three unbranded tablet presentations side by side showing different tablet sizes and a plain white carton for comparison.

Oral ivermectin in the US has historically been sold as a 3 mg tablet, and Medical News Today's dosage review, updated in April 2026, still describes the tablet as available in one strength: 3 mg. However, DailyMed labeling from Advagen Pharma covers ivermectin tablets in both 3 mg and 6 mg, and a 2026 filing posted on Regulations.gov describes ivermectin tablets USP in 3 mg, 6 mg, 9 mg, 12 mg and 15 mg. What you can actually pick up at a US pharmacy depends on the manufacturer stocked that week, so confirm the strength on the bottle before counting tablets.

12 mg tablets

The 12 mg tablet is widely marketed in other countries and is what many overseas dosing charts assume. In the US it has not been the standard retail strength. Mixing up a 3 mg tablet and a 12 mg tablet is a known source of dosing errors, which is why the strength printed on the bottle matters as much as the number of tablets.

Topical forms are dosed differently

Ivermectin also comes as a 1% cream for the inflammatory lesions of rosacea and a 0.5% lotion for head lice. These are applied, not swallowed, and weight-based tablet charts do not apply to them; see our explainer on ivermectin cream for how topical use differs.

Dosage by body weight (chart)

A pharmacist's hands using a counting tray and spatula to separate tablets into a weight-based dose.

The tables below reproduce the weight bands in the FDA-approved ivermectin tablet labeling, as summarized by the Stromectol prescribing information and by Drugs.com's dosage guide (last reviewed January 5, 2026). They apply to the two infections the FDA has approved ivermectin tablets to treat, in a patient with a confirmed diagnosis, and they are reference information rather than a self-dosing instruction.

We reproduce these bands because they are printed on an approved label. We do not extend them to any other use, and we do not work out a dose for a reader. Which indication applies, whether ivermectin is the right drug at all, and what to give at the top of the weight range are decisions for a prescriber who has examined the patient.

Strongyloidiasis — single dose, about 200 mcg/kg

Body weight Single oral dose Number of 3 mg tablets
15–24 kg (33–53 lb) 3 mg 1
25–35 kg (55–77 lb) 6 mg 2
36–50 kg (79–110 lb) 9 mg 3
51–65 kg (112–143 lb) 12 mg 4
66–79 kg (145–174 lb) 15 mg 5
80 kg and over (176 lb+) 200 mcg/kg, calculated Calculated by prescriber

Onchocerciasis — single dose, about 150 mcg/kg

Body weight Single oral dose Number of 3 mg tablets
15–25 kg (33–55 lb) 3 mg 1
26–44 kg (57–97 lb) 6 mg 2
45–64 kg (99–141 lb) 9 mg 3
65–84 kg (143–185 lb) 12 mg 4
85 kg and over (187 lb+) 150 mcg/kg, calculated Calculated by prescriber

Two practical points about ivermectin dosage for humans by weight. First, the bands differ between the two indications, so the same person can be prescribed a different number of tablets depending on the diagnosis. Second, the label does not establish safety and effectiveness in children weighing less than 15 kg, so pediatric dosing below that weight is not covered by the approved labeling.

How and when to take it

A single unbranded white tablet held in an open palm next to a clear glass of water on a kitchen table.

The approved labeling directs that ivermectin tablets be taken on an empty stomach with water. For strongyloidiasis the label states that, in general, additional doses are not necessary.

  • Timing: the label describes a single oral dose, taken with water, on an empty stomach.
  • Food effect: taking ivermectin with a high-fat meal substantially raises blood levels, which is part of why the label specifies an empty stomach — "with food" dosing used in some research protocols is not the approved instruction.
  • Follow-up: for strongyloidiasis, the label calls for repeat stool examinations to confirm the parasite is cleared, because recurrence has been documented months after treatment.
  • Repeat dosing: for onchocerciasis, the Stromectol label states that the most commonly used dose interval in international mass-treatment programs is 12 months, and that for an individual patient retreatment may be considered at intervals as short as 3 months. Whether to retreat, and when, is a prescriber's judgment rather than a schedule to set yourself.

Dosing for specific conditions

A gloved hand holding a plastic veterinary paste syringe above a stable workbench, illustrating animal-labeled products that are not for people.

Strongyloidiasis and onchocerciasis

These are the two FDA-approved oral indications, dosed as in the charts above. Ivermectin kills the immature larval stage rather than the adult worm in onchocerciasis, which is why periodic retreatment is part of the labeled approach.

Scabies and head lice

Oral ivermectin is not an FDA-approved treatment for scabies in the US. When clinicians use it for scabies, they are using it off-label, and CDC guidance for clinicians discusses oral ivermectin for crusted scabies and institutional outbreaks alongside topical permethrin. Because there is no approved label for that use, there is no labeled dose or repeat interval to report, and we do not publish one — the amount and the timing are set by the prescriber. For head lice, the approved product is a 0.5% topical lotion, not a tablet.

COVID-19 and influenza

Ivermectin is not approved by the FDA for COVID-19. The higher, multi-day regimens circulated online come from research protocols rather than from approved labeling, and we do not reproduce them here. Large randomized trials, including the NIH-funded ACTIV-6 program, did not find a meaningful benefit on symptom recovery in outpatients with mild-to-moderate COVID-19. Treat any dosing chart built around a respiratory infection as unsupported by regulators.

Prescription status, price and animal products

In most states ivermectin tablets require a prescription. Pharmacy Times reports that Arkansas enacted SB 189 / Act 396 on March 25, 2025 and Idaho enacted SB 1211 on April 14, 2025, each providing that ivermectin suitable for human use may be sold without a prescription or professional consultation in that state. A January 2026 WLBT report counted four states with non-prescription sales as of July 2025 — Tennessee, Arkansas, Idaho and Louisiana — while Mississippi lawmakers filed new bills in the 2026 session. Additional measures were pending rather than law, including South Carolina H. 3916 and a 2026 Missouri bill. Mechanics vary by state, so check your own board of pharmacy before assuming a pharmacy can sell it off the shelf. Cash prices for generic 3 mg tablets vary widely by pharmacy and quantity; a discount-price lookup such as GoodRx reflects current local pricing better than any figure printed in an article. Finally, ivermectin products sold for horses, cattle and other animals — pastes, drenches and injectables — are labeled for animal use only and are not approved for human use; they are far more concentrated than human tablets and are not made to human manufacturing standards.

Missed dose, overdose and safety limits

Because treatment for the approved indications is a single dose, a "missed dose" is an unusual situation, and the approved labeling does not give instructions for one. Ask the dispensing pharmacist or the prescribing clinician what to do about a dose taken late or skipped, rather than deciding on your own to double up.

There is no consumer-facing maximum daily dose printed on the label, because the label does not contemplate self-directed multi-day use. The practical safety limit is the prescribed weight-based dose. Reported problems with excess ivermectin — most often after use of animal-strength products or repeated high doses — have included nausea and vomiting, diarrhea, low blood pressure, dizziness, confusion, tremor, visual disturbance and in severe cases seizures. Call Poison Help at 1-800-222-1222 in the US if too much has been taken.

Who needs extra caution

  • Children weighing under 15 kg, where labeled safety and effectiveness are not established.
  • People who are pregnant or breastfeeding, who should discuss the risk-benefit balance with a clinician.
  • People with weakened immune systems, who may need repeat dosing and closer follow-up.
  • Anyone with possible Loa loa infection after travel to Central or West Africa, given the risk of serious reactions.
  • People taking warfarin or other interacting medicines — a fuller rundown is in our overview of ivermectin uses and side effects.

Frequently asked questions

How many 3 mg tablets is a normal adult dose?

That depends on the diagnosis, and it is not a number to settle on your own. Under the Stromectol label, the band for a 51–65 kg adult being treated for strongyloidiasis is four 3 mg tablets as a single dose, and the band for a 65–84 kg adult being treated for onchocerciasis is also four tablets. Above the top band the label gives a per-kilogram figure for the prescriber to apply. For any use the FDA has not approved, there is no labeled band, and we do not supply one.

Does the ivermectin dose for humans change with food?

The approved labeling says to take tablets on an empty stomach with water. Fatty food increases absorption, so taking it with a meal does not simply produce the same exposure.

Is ivermectin available over the counter now?

Not nationally. Five states — Tennessee, Arkansas, Idaho, Louisiana and Texas — have enacted laws permitting sale or pharmacist dispensing without a prescription. Texas was the most recent; its law took effect on December 4, 2025. Federal approval status has not changed, and state rules differ, so check your own state. These details were verified on September 26, 2026.

Can I use a horse paste and scale the dose by weight?

No. Veterinary ivermectin pastes and injectables are labeled for animal use only and are not approved for people; they are highly concentrated, hard to measure accurately, and may contain inactive ingredients never evaluated in humans.

Is a second dose needed?

Sometimes. The label describes periodic retreatment for onchocerciasis, and it notes that immunocompromised patients being treated for strongyloidiasis may need repeated courses, with stool testing to confirm clearance. For uses outside the approved label there is no labeled repeat schedule to go by. In every case, that decision belongs with the treating clinician.

Sources