What are the approved human ivermectin tablet strengths and typical dosing regimens?
Executive summary
Ivermectin tablets for humans are marketed primarily in a 3 mg strength (with some labeling records also listing a 6 mg presentation) and are approved to treat parasitic infections using weight‑based single doses—typically in the range of 150 to 200 micrograms per kilogram (mcg/kg) given once, with repeat or suppressive regimens used for certain indications (for example, onchocerciasis or difficult strongyloidiasis) [1] [2] [3]. Public discussion about much higher doses for COVID‑19 is inconsistent with approved regimens and pharmacokinetic data showing required antiviral concentrations would far exceed safe, approved dosing [4] [5].
1. What strengths are approved and where that confusion comes from
The commonly referenced human oral ivermectin tablet in U.S. labels is 3 mg per tablet, listed in product monographs and prescribing information (DailyMed and Mayo Clinic drug summaries note each tablet contains 3 mg) [2] [6], while some FDA/NCTR records and older labeling documents also reference 6 mg tablets in certain set‑IDs (the FDA SPL listing for “Ivermectin Tablets, USP 3 mg and 6 mg” reflects how forms and listings vary across sources) [1]. The safest reading for clinicians and patients is that ivermectin human tablet dosing is delivered as small fixed‑dose tablets (commonly 3 mg), with the actual therapeutic dose calculated by patient weight and not by taking a fixed number of tablets without professional guidance [2] [6].
2. Typical, approved dosing regimens by indication
For intestinal strongyloidiasis and onchocerciasis—two primary FDA‑approved oral indications—the evidence and approved labels describe single, weight‑based doses around 150–200 mcg/kg: many clinical studies used a single dose of approximately 200 mcg/kg (often rounded to 150 mcg/kg for onchocerciasis trials), and labels give tables to translate body weight into the number of 3 mg tablets required for an appropriate single dose [3] [1] [2]. Some conditions (for example, onchocerciasis mass‑drug administrations or repeat therapy in endemic settings) use repeated dosing at intervals such as 3 months to 12 months, and extra‑intestinal or chronic strongyloidiasis in immunocompromised patients may require repeated or monthly suppressive therapy because cure can be difficult to achieve with a single dose [1] [2] [6].
3. Practical translation: how many tablets and administration tips
Because dosing is weight‑based, the number of 3 mg tablets needed varies; prescribing information and drug references provide conversion tables to calculate the number of tablets to reach ~150–200 mcg/kg [3] [2]. Instructions in prescribing labels also recommend taking tablets on an empty stomach with water and caution that additional doses are generally unnecessary for routine cases, although follow‑up testing is advised to confirm eradication [3] [2].
4. Off‑label use, safety limits and why higher dosing has been rejected
Clinical guidance and regulatory communications emphasize that ivermectin is not approved for COVID‑19 and that achieving in‑vitro antiviral concentrations would require doses many times higher than approved and likely unsafe (pharmacokinetic modeling suggests up to 100‑fold increases would be needed) [4] [5]. Safety summaries and case reports warn of overdose risks with very high dosing—including neurotoxicity and other systemic effects—and regulatory bodies have discouraged self‑medication with veterinary products or dose escalation beyond established weight‑based regimens [5] [4] [7]. Alternative views advocating higher or prolonged dosing for non‑approved uses exist in public forums, but major clinical trials (e.g., ACTIV‑6, TOGETHER) failed to show clinical benefit for COVID‑19 at tested regimens and underscore that evidence‑based dosing remains the weight‑based 150–200 mcg/kg single dose for approved parasitic indications [4].
5. Transparency and sources of bias to watch for
The debate around ivermectin has mixed clinical science, media amplification and political advocacy; FDA and NIH guidance focuses on approved parasite indications and pharmacology data, while some advocacy or online sources push off‑label use without supporting pharmacokinetic rationale—readers should privilege FDA/label data, peer‑reviewed trials and clinical guidelines when assessing dosing claims [5] [4] [3]. Where documents list multiple tablet strengths or historical labels, that can create confusion—clinicians should rely on up‑to‑date product labels and institutional formularies to calculate weight‑based dosing from the 3 mg tablet reference [2] [1].