What are the FDA‑approved numeric dosing regimens (mg/kg and schedule) for ivermectin in its labeled human indications?
Executive summary
The FDA‑approved oral ivermectin (Stromectol) for human parasitic infections is dosed by body weight, most commonly as a single dose in the range of 150 to 200 micrograms per kilogram (mcg/kg) depending on the program and indication, with repeat dosing intervals varying by disease control programs (single‑dose: 150 mcg/kg is commonly used in mass campaigns; clinical trials and labeling report 200 mcg/kg single doses used for cure) [1] [2] [3]. Topical formulations are FDA‑approved for conditions such as rosacea and head lice, but the publicly available label text in these sources does not provide an equivalent mg/kg numeric systemic dosing for topical products [4].
1. Labeled human indications and formulations — what the FDA authorizes
The FDA affirms oral ivermectin tablets are approved for treatment of certain parasitic worm infections in humans, and there are separate topical (skin) formulations approved for conditions such as rosacea and head lice; veterinary formulations are distinctly different and not approved for human use [4]. The labeled oral product marketed as Stromectol has been used and studied specifically for onchocerciasis and other parasitic indications in clinical trials and labeling documents [2] [1].
2. Numeric dosing regimens — the oral tablet (mg/kg and schedule)
The FDA label and authoritative clinical references report single‑dose regimens based on body weight: a single 150 mcg/kg oral dose is commonly used (and designed tablet strengths approximate a 150 mcg/kg target per dosing tables), while clinical studies and labeling also reference a single 200 mcg/kg dose as an effective regimen in trials where cure rates of 64–100% were observed after a single 200 mcg/kg dose [1] [2] [3]. Patients are instructed to take tablets on an empty stomach with water in the labeled oral regimen; tablet strength for the human oral formulation is 3 mg per tablet as described in prescribing summaries [1] [3].
3. Repeat dosing, population programs and schedule nuances
Mass drug administration programs commonly use an annual (12‑month) dosing interval in endemic areas, where the single dose is often the 150 mcg/kg regimen; labeling and program descriptions note intervals of every 3 to 12 months may be used clinically depending on the condition and local practice [1] [3]. The label also documents pharmacokinetic differences with food (higher bioavailability after a high‑fat meal) and details safety findings from higher‑dose exposure studies, but the approved human schedules remain single‑dose weight‑based regimens with repeat intervals determined by indication or program [2] [1].
4. What the FDA has not approved — clarifying common confusion
The FDA explicitly states it has not authorized or approved ivermectin for prevention or treatment of COVID‑19 in humans or animals and has warned against using veterinary formulations in people because the safety of animal formulations in humans is unknown [4]. Clinical trials exploring higher or multi‑day regimens for COVID‑19 have used experimental dosing schemes (for example, 400 mcg/kg for 3 days or 600 mcg/kg for 6 days in some trials), but those are investigational regimens and not FDA‑approved labeled uses [5].
5. Caveats, competing data and reporting limits
Official labeling and clinical monographs show some variation in cited typical doses (150 mcg/kg vs 200 mcg/kg single dose) because different indications, historical trials, and mass‑treatment protocols have used slightly different weight‑based targets; the prescribing information and authoritative clinical sites reflect those variants without changing that the product is weight‑based and most often given as a single oral dose [2] [1] [3]. The reviewed sources do not provide a full numeric mg/kg equivalent for topical products nor exhaustive tables for every labeled indication in this summary; for precise per‑indication dosing tables, the current official FDA label and the full Stromectol prescribing information should be consulted [2] [1].