The use of ivermectin to treat COVID-19 is an ongoing debate. The central conflict is that although many doctors have reported success in using ivermectin, some studies published in major journals suggest it is in fact ineffective.
People who trust ivermectin claim that the studies showing ineffectiveness are fraudulent, while people who are skeptical of its use for treating COVID-19 view that as an anti-science conspiracy theory.
Legacy Media Report Ineffectiveness
Numerous preclinical studies have found that ivermectin has a broad range of effects on COVID-19, spanning from its initial effect on viral infection to its effect on the pathological changes the virus causes in our bodies.Ivermectin exceeds the approved antiviral effects of other medications, including Paxlovid, molnupiravir, and remdesivir, which target only the virus and lack anti-inflammatory and organ-protective effects. Monoclonal antibodies have to be constructed specific to each variant and are very expensive.
In the pharmaceutical industry, clinical trials are commonly used to evaluate the efficacy and safety of drugs once their mechanism is demonstrated. There are two types of clinical trials: observational and interventional.
Observational studies are often conducted by doctors in clinical, hospital, or community settings to analyze the effects of drugs. The data are collected as observed in clinical practice with minimal interference.
Pharmaceutical companies are required to conduct interventional studies that meet the approval standards set by the U.S. Food and Drug Administration (FDA). Randomized clinical trials (RCTs) are frequently used to fulfill these requirements. This type of study is considered the gold standard and involves randomly assigning one group of patients to receive a specific drug while the other group does not receive it, then comparing the outcomes.
Legally and medically, ivermectin can be prescribed off-label to treat COVID-19 since it has already been approved by the FDA for other diseases.
Although many doctors have observed the positive effects of ivermectin in treating their patients, the media have specifically highlighted data from a few selected RCTs that have concluded it is ineffective in treating COVID-19.
However, some critical aspects were overlooked in those RCTs.
Improper Dosing
A drug’s therapeutic effects can be observed only when it reaches the appropriate concentration in the body and remains there for a few days, allowing sufficient time to work.Recommended Dosage
According to Merck’s package insert for ivermectin (brand name Stromectol), a single oral dose of 0.2 mg/kg was officially recommended for treating parasitic diseases. There is no official dose for COVID-19.The recommended dosage of ivermectin for treating COVID-19 is based on the clinical experiences of physicians worldwide.
It is common for a drug with multiple indications to have different doses for different diseases.
RCT Studies Used Inappropriate Dosing
In the most recent PRINCIPLE trial published in March, ivermectin was used at 0.3 mg/kg for only three days. Moreover, it was designed to dose the ivermectin without food: “Participants were advised not to eat two hours before or after taking ivermectin.”Ivermectin was reported as dosed at 0.4 mg/kg for three days—a much shorter time period than it should be. However, in the protocol Table 4 in Appendix 16.3.3, the precise dosing was as low as 0.269 mg/kg, and 0.4 mg/kg is actually only the upper dose limit—not the real dose.
Clinical Improvement Despite Underdosing
It is inappropriate to conclude that ivermectin was ineffective based on these RCT studies with major design flaws.Despite the poor study design, ivermectin showed clinical benefits and saved lives.
In the PRINCIPLE study, self-reported recovery was shorter in the ivermectin group than in the group receiving usual care, with a median decrease of 2.06 days. The statistical analysis showed that it met the predefined superiority criteria.
Furthermore, the analysis showed that ivermectin effectively reduced COVID-19-related hospitalizations and deaths. Only 1.6 percent of 2,157 patients in the ivermectin group experienced hospitalizations or deaths, compared with 4.4 percent of 3,256 patients in the usual care group.
Even a low dose of ivermectin has demonstrated the potential to save lives. However, the authors concluded, “Ivermectin for COVID-19 is unlikely to provide clinically meaningful improvement in recovery, hospital admissions, or longer-term outcomes.”
Statistical Failures
It is important to note that the definition of treatment effects in an RCT can differ from those discussed in real-life observational studies.Sometimes, even if the results of a clinical trial demonstrate a clear effect, the conclusion may still be interpreted as ineffective because of the statistical definition of effectiveness.
Interpreting statistics can be challenging as they usually involve complicated mathematical models and numerical data that can be manipulated to support a specific agenda. Nevertheless, for the purpose of this discussion, let’s presume that all research is carried out conscientiously and without manipulative intent.
In other words, ivermectin reduced the risk of death by 100 percent and the need for ventilators by 80 percent.
P-values are commonly used to test and measure a “null hypothesis,” which states that no differences exist in the effects being studied between two groups. A finding is considered statistically significant and warrants publication when the p-value is 0.05 or less.
The p-values in this study were deemed insignificant because they were more than 0.05. Accordingly, the authors wrote that this difference was statistically insignificant and concluded that ivermectin “had shown only marginal benefit.”
How could a 100 percent reduction in death or an 80 percent reduction in ventilation be interpreted as “marginal” effects?
The same conclusion was made as the previous study because the p-value was 0.09, higher than 0.05.
The lifesaving potential of ivermectin has been hindered by the unnecessary statistical threshold. The problem of statistical significance is widespread and frequently causes confusion among scientists.
The authors called for abandoning the use of statistical significance to draw conclusions regarding the effectiveness of drugs, such as stating that “drug Y does not work,” and cautioned that such conclusions may result in the dismissal of potentially lifesaving drugs.
Selection Bias
Many people, including physicians, may not be aware that interventional studies, particularly RCTs, are prone to numerous biases, with selection bias being one of the most significant. Excluding potentially eligible individuals because of their anticipated group allocation can lead to selection bias.It’s common knowledge that early treatment of COVID-19 is crucial for effective results. The earlier the treatment starts, the more effective it is. These approved antivirals for COVID-19 are used shortly after COVID-19 infection and usually within a few days after symptom onset.

However, in the PRINCIPLE trial, ivermectin was used for patients within 14 days of symptom onset, while ACTIV-6 treated patients an average of six days after infection.
Why was ivermectin treated so unfairly in these clinical trials?
Proven Without a Profit Motive
Conducting an RCT to get a drug approved by the FDA requires money. Every drug must be managed by a professional team composed of doctors, database managers, and assistants. Professionals must secure funding, recruit a lead investigator, and find hospitals to conduct the study. An operational team must perform the study, analyze the data, and gain FDA approval.Since ivermectin is a generic drug that lacks profitable marketing and a pharmaceutical sponsor, it’s challenging to organize and systematically manage its new application with health authorities, data, and customers.
Nevertheless, doctors worldwide have been using ivermectin to help patients and have collected valuable data.
Since the beginning of the analysis, ivermectin has consistently shown efficacy. This meta-analysis provides a thorough and transparent real-time analysis of all eligible ivermectin studies.
The trials were conducted by 1,139 doctors or scientists from 29 countries with 142,307 patients. Out of the total studies, 86 have been peer-reviewed with 128,787 patients, and 49 were randomized controlled trials with 16,847 patients.
In the studies with comparative groups, ivermectin was shown to reduce the risk of COVID-19 infection by 81 percent, mortality by 49 percent, ICU admission by 35 percent, ventilation usage by 29 percent, and hospitalization by 34 percent.
In comparison with the control groups, the group treated with ivermectin as a preventive measure before infection experienced reductions in the most severe clinical outcomes of COVID-19 by 85 percent. When used in the early stage of COVID-19, ivermectin decreased the severity of the disease by 62 percent, and when used in late stages, it reduced the clinical severity by 39 percent. Clinical severity is measured by death, ventilation, disease progression, and hospitalization.

Considering the Entire Picture
It’s difficult to believe that the designers of these studies were unaware of the dosing of ivermectin. Despite all the above analyses, the reasoning behind the ivermectin underdosing or unfavorable study design may be linked to factors beyond science.A new drug or vaccine cannot achieve an emergency use authorization status if there is an existing viable therapeutic available. This fact alone may have affected many decisions.
It’s important to keep an open mind and consider the entire picture when examining the ivermectin issue, rather than dismissing it as conspiracy or misinformation. This can lead to more informed decisions that could ultimately save lives.