Fact check: What are the potential risks of taking ivermectin without a prescription?

1. What advocates and warnings both claim — and where the evidence lines up

Public claims that ivermectin is a safe, effective self-treatment for viral infections led to widespread self-medication during the COVID-19 pandemic; regulatory and clinical literature documents a corresponding rise in adverse-event reports after May 2020, primarily gastrointestinal and neurological, indicating a temporal association between off-label use and harms ^[2]. Systematic pharmacovigilance work from 2021 found serious adverse reactions, including encephalopathies, even outside regions with confounding parasitic infections such as loiasis, demonstrating that reported harms are not solely attributable to endemic co-infections ^[1]. These findings together show that empirical safety signals grew as non-prescribed use increased ^{[2] [1]}.

2. Neurological dangers: from confusion to encephalopathy and seizures

Clinical case reports and pharmacovigilance analyses describe acute encephalopathy, confusion, ataxia, and seizures following ivermectin misuse or overdose, with case timelines often showing rapid onset of neurotoxicity after excessive or inappropriate dosing ^{[5] [6]}. The 2021 case series and later pharmacovigilance reviews recorded neurological events that required medical attention, and systematic studies emphasize these are not isolated anecdotes but reproducible signals across regions and databases ^{[1] [2]}. These data indicate that unsupervised ivermectin use can produce potentially life-threatening central nervous system effects, particularly when dosing is incorrect.

3. Skin and systemic reactions that can be catastrophic

Pharmacovigilance analysis in 2022 identified a strong safety signal for severe cutaneous adverse reactions—including Stevens-Johnson syndrome and toxic epidermal necrolysis—associated with systemic ivermectin, representing rare but devastating outcomes that demand dermatologic awareness and urgent care ^[7]. Broader adverse-event surveillance captured gastrointestinal and systemic symptoms as common complaints in reported cases, suggesting a spectrum from mild to severe reactions. The aggregation of these reports supports a conclusion that unsupervised use can produce both frequent, manageable side effects and uncommon, catastrophic skin or systemic manifestations ^{[2] [7]}.

4. Product quality: counterfeit and substandard tablets magnify risk

Analytical work from samples collected during the pandemic found none of the self-medication ivermectin samples met quality criteria, raising the risk that consumers obtain ineffective or toxic formulations (published sample analysis dated 2024/09) ^[3]. Substandard or falsified medications can lead to underdosing (therapeutic failure), overdosing (excess toxicity), or exposure to contaminants, and these risks compound those inherent to ivermectin itself when taken without professional oversight. The presence of unregulated supply chains and counterfeit products creates a parallel hazard that is often overlooked in clinical discussions of drug safety ^[3].

5. Mechanisms and experimental signals that explain clinical harms

Laboratory and animal studies from 2025 identify oxidative stress, P‑glycoprotein disruption, and histological damage in brain and skin tissues after acute ivermectin toxicity, providing biological plausibility for the neurological and dermatologic adverse events reported in humans ^[4]. Earlier human case reports documenting encephalopathy after overdose align with these mechanistic findings and suggest dose-dependent vulnerability, especially where blood–brain barrier transporters are impaired. Experimental findings also note candidate interventions—flumazenil and vitamin C in animal models—that warrant further clinical study but do not substitute for evidence-based prescribing ^{[4] [6]}.

6. Surveillance trends and public‑health implications since 2020

Global pharmacovigilance databases registered a notable uptick in ivermectin-related adverse-event reports beginning May 2020, reflecting the pandemic-era surge in non-prescribed use and drawing attention from WHO safety reviewers ^[2]. Regulatory bodies and clinicians face the twin challenges of managing individual toxicities and countering misinformation that encourages self-medication; public‑health responses must address supply-chain quality, clinician education, and community outreach to reduce unsupervised consumption and its documented harms ^{[2] [3]}.

7. The factual bottom line for clinicians, regulators and the public

The consolidated evidence from 2021–2025 demonstrates that unsupervised ivermectin use carries measurable risks: neurological dysfunction including encephalopathy and seizures, severe cutaneous reactions, gastrointestinal and systemic effects, plus hazards from counterfeit or poor‑quality products and biologically plausible mechanisms of tissue injury ^{[1] [2] [3] [7] [4]}. Medical supervision ensures appropriate indication, dose adjustment, and monitoring for interactions and adverse effects; absent that oversight, the documented safety signals and product-quality failures make self-medication a demonstrable public-health hazard ^{[2] [3]}.