Bret Weinstein & Dr. Pierre Kory on the Joe Rogan Experience #1671, fact-checked

What the evidence shows: In November 2020, a WHO guideline panel issued a conditional recommendation against using remdesivir in hospitalized COVID-19 patients regardless of severity, based on pooled data from four randomized trials (about 7,300 patients) showing no clear effect on mortality, need for mechanical ventilation, or time to clinical improvement; that part of Kory's claim was accurate as of this June 2021 episode, when the WHO guidance against remdesivir was still in effect (WHO later revised its position in April 2022, moving to a conditional recommendation in favor of remdesivir for severe COVID-19). In the US, remdesivir received FDA approval and was incorporated into NIH and IDSA treatment guidelines as a treatment option for hospitalized patients and became a common therapy, but utilization data from large retrospective cohorts show initiation rates around 50-55% of hospitalized COVID-19 patients in 2021-2024, with usage varying by disease severity, hospital, and time period (reaching up to roughly 79% among ventilated patients at the 2020 peak). This falls well short of "every single" hospitalized patient receiving the drug, so the claim of universal administration is an overstatement, even though remdesivir did become a widely used standard-of-care therapy in US hospitals.

What the evidence shows: The meta-analysis Kory referenced, by Bryant, Lawrie et al. (published in the American Journal of Therapeutics in mid-2021), reported roughly a 62% reduction in COVID-19 mortality among patients treated with ivermectin, pooling data from a number of randomized controlled trials. In January 2022 the same journal issued a formal Expression of Concern for that meta-analysis, noting that several of the included trials, most notably an Egyptian study by Elgazzar and colleagues that contributed heavily to the mortality signal, had serious data integrity problems and were later shown to contain likely fabricated or duplicated data; that trial was subsequently retracted from its preprint server. Once such compromised or low-quality trials are excluded, later and larger high-quality randomized trials found no significant mortality or clinical benefit from ivermectin: the NEJM-published TOGETHER trial (2022) and the JAMA-published ACTIV-6 trials (2022, 2023) each found ivermectin did not meaningfully reduce hospitalization, disease progression, or time to recovery compared with placebo. Current mainstream scientific consensus, reflected in these subsequent large trials, is that the 62% mortality-reduction figure Kory cited rested substantially on trials with serious methodological and integrity flaws and has not been replicated by more rigorous studies.

What the evidence shows: Weinstein described a study of frontline workers in which 57% of a 400-person unmedicated control group contracted COVID, implying ivermectin's prophylactic effect approached 100%. No peer-reviewed or preprint study matching those specific figures (400 controls, 57% infection rate) was found. The Argentine trial most commonly cited for ivermectin pre-exposure prophylaxis in health workers (Chahla et al., 2021) had a control group of only 117 people, of whom 15 (about 13%) tested positive for COVID-19, and it tested ivermectin combined with a nasal spray (iota-carrageenan), not ivermectin alone. A larger Indian case-control study (186 matched pairs) found a 73% relative reduction in infection with two-dose ivermectin, still well short of near-100% efficacy, and as an unblinded observational study it is vulnerable to confounding by health-conscious behavior among ivermectin users. The largest, most rigorous evidence, the placebo-controlled ACTIV-6 randomized trial (JAMA, 2022, n=1591), found no clinically meaningful benefit of ivermectin against COVID-19. Overall, the specific numbers Weinstein cited do not match any identifiable published study, and the broader body of controlled evidence does not support a near-100% prophylactic effect for ivermectin.

What the evidence shows: Kory is describing IMSS (Mexico's social security agency), which in late 2020/early 2021 ran a test-and-treat program offering ivermectin to COVID-19 outpatients, and he cites an internal IMSS report claiming up to a 75% lower hospitalization rate among those who took it. That report was not a randomized controlled trial: it was an uncontrolled observational comparison released by the agency itself, not a peer-reviewed study, so its 75% figure has not been independently validated. A 2023 systematic review published in BMJ Global Health assessed the underlying clinical trial evidence for ivermectin COVID-19 kit distribution programs across eight Latin American countries, including Mexico. It found that of the 33 randomized controlled trials of ivermectin for COVID-19 available at the time, the majority carried a substantial risk of bias under GRADE criteria, and concluded that Latin American governments distributed ivermectin-containing kits to their populations without high-quality evidence that the drug reduced hospitalization or mortality. That review did not evaluate the IMSS program's specific 75% figure directly, but its finding that the broader evidence base for ivermectin kit distribution was low-quality and largely unsupported by rigorous trials undercuts the reliability of Kory's claim. Independent, well-controlled randomized trials of ivermectin conducted around the same period found no significant reduction in hospitalization or disease progression, further weakening the basis for treating the IMSS figure as reliable evidence of ivermectin's effect.

What the evidence shows: The 58% figure Rogan cites closely matches an unblinded, open-label Argentine trial (Chahla et al.) of household contacts of COVID-19 patients, which reported 7.4% infection in the ivermectin group versus 58.4% in the no-treatment group; that study was assessed as high risk of bias due to lack of blinding, insufficient reporting on randomization and allocation concealment, and PCR confirmation performed on only 16 of 340 participants. A separate, frequently cited Argentine prophylaxis study associated with Dr. Hector Carvallo (sometimes called the IVERCAR protocol) tested ivermectin combined with iota-carrageenan, not ivermectin alone, making it impossible to attribute any protective effect to ivermectin specifically; a related, larger Carvallo observational study used a four-drug combination (ivermectin, enoxaparin, aspirin, and dexamethasone) rather than ivermectin alone. A separate systematic review and meta-analysis of ivermectin prophylaxis trials found inconsistent, low-certainty evidence for COVID-19 prevention. Larger, higher-quality randomized controlled trials of ivermectin for COVID-19 prevention and treatment have not replicated effects of this magnitude. The claimed 0% versus 58% figures therefore likely reflect a high-risk-of-bias, unblinded trial rather than a rigorous prophylaxis RCT, and do not reflect the current weight of controlled-trial evidence on ivermectin as COVID-19 prophylaxis.

What the evidence shows: Some small early trials, including a 2021 double-blind, placebo-controlled pilot RCT (Chaccour et al., n=24), reported a shorter time to viral clearance with ivermectin, but these studies were small, methodologically limited, and not adequately powered to establish efficacy. The largest and most rigorous trial to date, the TOGETHER trial (Reis et al., NEJM 2022), a double-blind, randomized, placebo-controlled adaptive platform trial of 1,358 outpatients in Brazil, found no significant benefit of ivermectin on its primary clinical outcome (hospitalization or emergency observation for COVID-19 worsening: relative risk 0.90, 95% credible interval 0.70-1.16) and no significant effect on secondary outcomes. A 2022 Cochrane systematic review of 11 RCTs (3,409 participants), which graded evidence certainty using GRADE, found the effect of ivermectin on viral clearance in outpatients with mild COVID-19 was uncertain, with low- to very-low-certainty evidence not supporting a meaningful clinical effect. As of the most recent Cochrane update, the overall body of RCT evidence does not support ivermectin as an effective COVID-19 treatment, and it is not recommended by major health authorities for that purpose. Kory's claim overstates the strength and consistency of the trial evidence, citing early small studies while omitting larger, higher-quality trials that found no meaningful clinical benefit.