What are the on-label and off-label uses of ivermectin?
Executive summary
Ivermectin is an antiparasitic medicine with a small set of FDA‑approved, “on‑label” human uses—oral formulations for certain parasitic worms and topical formulations for skin and lice—while a range of other applications have been tried or promoted “off‑label,” most controversially for COVID‑19 and, more recently, in anecdotal cancer claims [1] [2] [3] [4]. Regulators worldwide have warned against using ivermectin to prevent or treat viral illnesses absent high‑quality evidence, even as laws and local practice allow physicians to prescribe off‑label when they judge it appropriate [5] [3] off-label-as-a-treatment-for-covid-19-2" target="blank" rel="noopener noreferrer">[6] [7].
1. What “on‑label” means and what ivermectin is approved to treat
On‑label indications are the specific uses a drug’s regulatory label permits based on evidence submitted to the approving agency, and for ivermectin that includes oral tablets (Stromectol) for strongyloidiasis and onchocerciasis, a cream (Soolantra) for rosacea, and a lotion (Sklice) for head lice as reflected in prescribing information and summary resources [1] [2].
2. Common off‑label clinical uses with some supporting practice evidence
Clinicians have used ivermectin off‑label for scabies and other parasitic infections beyond the narrow label, and in some jurisdictions physicians have legally prescribed it for conditions they consider appropriate with patient consent, reflecting standard off‑label practice across medicine [1] [7] [8].
3. The COVID‑19 controversy: claims, evidence, and regulatory stance
During the COVID‑19 pandemic ivermectin was widely promoted as a treatment or prophylactic despite major health agencies — including the U.S. FDA, WHO and EMA — concluding that existing data do not support its use for COVID‑19 and advising against it outside clinical trials; the FDA explicitly states it has not authorized ivermectin for preventing or treating COVID‑19 [5] [3] [9]. That divergence between public demand and regulatory advice fueled off‑label prescribing, raw use of veterinary formulations, poison center surges, and international policy differences where some governments or practitioners permitted compassionate or off‑label use despite the lack of robust trial evidence [3] [10] [8].
4. Safety, interactions, and real‑world harms tied to off‑label use
Ivermectin has a documented safety profile for approved uses, but overdoses or ingestion of veterinary products can cause nausea, neurologic effects, seizures or worse, and the drug can interact with other medicines including blood thinners — harms underscored by poison control reports and FDA warnings during the pandemic [2] [10] [5]. Clinical uncertainty around optimal dosing for unapproved indications increases the risk of adverse events when used off‑label [10] [2].
5. Legal and political dimensions of off‑label prescribing
Off‑label prescribing is a legal and common medical practice in many countries and regulators cannot generally prohibit physicians from prescribing a drug for uses not on the label, but that fact has been politicized in debates over ivermectin; legislative changes and interpretive moves have even raised concerns that agencies might seek expanded authority to restrict certain off‑label uses, prompting pushback from some clinicians and commentators [6] [7] [11].
6. Emerging off‑label claims beyond COVID and the limits of current reporting
Newer claims — including that ivermectin aids cancer therapies — have circulated in social media and some preliminary studies, but they remain unsupported by large, high‑quality human trials and have provoked caution from public health monitors because promoting unproven uses can divert patients from effective treatments [4] [12]. Reporting shows both legitimate clinical judgment in limited off‑label contexts and a parallel economy of anecdote, misinformation, and policy variation; the sources consulted document regulatory warnings and real‑world harms but do not furnish definitive clinical trial data to endorse ivermectin for viral infections or cancer [5] [4] [3].