A 2015 study in the British Medical Journal BMJ Open found that cloth masks were penetrated by 97% of particles and may increase infection risk by retaining moisture or repeated use.

A) Studies on the effectiveness of face masks

So far, most studies found little to no evidence for the effectiveness of face masks in the general population, neither as personal protective equipment nor as a source control.

  1. A May 2020 meta-study on pandemic influenza published by the US CDC found that face masks had no effect, neither as personal protective equipment nor as a source control. (Source)
  2. WHO review of ten randomized controlled trials of face masks against influenza-like illness, published in September 2019, found no statistically significant benefit. (Source)
  3. Danish randomized controlled trial with 6000 participants, published in the Annals of Internal Medicine in November 2020, found no statistically significant effect of high-quality medical face masks against SARS-CoV-2 infection in a community setting. (Source)
  4. A large randomized controlled trial with close to 8000 participants, published in October 2020 in PLOS One, found that face masks “did not seem to be effective against laboratory-confirmed viral respiratory infections nor against clinical respiratory infection.” (Source)
  5. A February 2021 review by the European CDC found no high-quality evidence in favor of face masks and recommended their use only based on the ‘precautionary principle’. (Source)
  6. A July 2020 review by the Oxford Centre for Evidence-Based Medicine found that there is no evidence for the effectiveness of face masks against virus infection or transmission. (Source)
  7. A November 2020 Cochrane review found that face masks did not reduce influenza-like illness (ILI) cases, neither in the general population nor in health care workers. (Source)
  8. An August 2021 study published in the Int. Research Journal of Public Health found “no association between mask mandates or use and reduced COVID-19 spread in US states.” (Source)
  9. An experimental study using virus aerosols, published in May 2022 in the Journal of Infectious Diseases, found that only professionally fit-tested N95/FFP2 masks, but not surgical masks or non-fitted N95/FFP2 masks, reduced viral loads in nostrils. (Source)
  10. A large Spanish school study, published in March 2022, found that “mask mandates in schools were not associated with lower SARS-CoV-2 incidence or transmission.” (Source)
  11. A May 2020 article by researchers from Harvard Medical School, published in the New England Journal of Medicine, concluded that face masks offer “little, if any, protection”. (Source)
  12. A 2015 study in the British Medical Journal BMJ Open found that cloth masks were penetrated by 97% of particles and may increase infection risk by retaining moisture or repeated use. (Source)

B) WHO review of face mask trials (2019)

In September 2019, shortly before the coronavirus pandemic, the World Health Organization (WHO) published a comprehensive report on “Non-pharmaceutical public health measures for mitigating the risk and impact of epidemic and pandemic influenza”.

The report reviewed ten randomized controlled trials concerning the effectiveness of face masks against influenza-like illness (ILI). As the following table shows, none of the trials found a statistically significant benefit of face masks.


C) Development of cases after mask mandates

In many states, coronavirus infections strongly increased after mask mandates had been introduced. The following charts show the typical examples of Austria, Belgium, France, Germany, Ireland, Italy, Spain, the UK, California and Hawaii. Furthermore, a direct comparison between US states with and without mask mandates indicates that mask mandates have made no difference. (Charts: Y. Weiss)

For an updated version of these charts, see the postscript below.













D) Effectiveness of N95/FFP2 mask mandates

In January 2021, the German state of Bavaria was one of the first places in the world to mandate N95/FFP2 masks in most public settings. A comparison with other German states, which required cloth or medical masks, indicates that even N95/FFP2 masks have made no difference.


In January 2021, Austria was the first country in the world to introduce an N95/FFP2 mask mandate at the national level. The mandate was further expanded in September 2021. Nevertheless, by November 2021 Austria reported the highest infection rate in the world.


E) Additional aspects

  1. There is increasing evidence that the novel coronavirus is transmitted, at least in indoor settings, not primarily by droplets but by much smaller aerosols. However, due to their large pore size and poor fit, most face masks cannot filter out aerosols (see video analysis below): over 90% of aerosols penetrate or bypass the mask and fill a medium-sized room within minutes.
  2. The WHO admitted to the BBC that its June 2020 mask policy update was due not to new evidence but “political lobbying”: “We had been told by various sources WHO committee reviewing the evidence had not backed masks but they recommended them due to political lobbying. This point was put to WHO who did not deny.” (D. Cohen, BBC Medical Corresponent).
  3. To date, the only randomized controlled trial (RCT) on face masks against SARS-CoV-2 infection in a community setting found no statistically significant benefit (see above). However, three major journals refused to publish this study, delaying its publication by several months.
  4. An analysis by the US CDC found that 85% of people infected with the new coronavirus reported wearing a mask “always” (70.6%) or “often” (14.4%). Compared to the control group of uninfected people, always wearing a mask did not reduce the risk of infection.
  5. Researchers from the University of Minnesota found that the infectious dose of SARS-CoV-2 is just 300 virions (virus particles), whereas a single minute of normal speaking may generate more than 750,000 virions, making face masks unlikely to prevent infection.
  6. Contrary to common belief, studies in hospitals found that the wearing of a medical mask by surgeons during operations didn’t reduce post-operative bacterial wound infections in patients.
  7. Many health authorities argued that face masks suppressed influenza; in reality, influenza was temporarily displaced by the more infectious coronavirus. Indeed, influenza disappeared even in states without masks, lockdowns and school closures (e.g. Sweden and Florida).
  8. The initially low coronavirus infection rate in some Asian countries was not due to masks, but due to very rapid border controls. For instance, Japan, despite its widespread use of face masks, had experienced its most recent influenza epidemic just one year prior to the covid pandemic.
  9. Early in the pandemic, the advocacy group “Mask for All” argued that Czechia had few infections thanks to the early use of masks. In reality, the pandemic simply hadn’t reached Eastern Europe yet; a few months later, Czechia had one of the highest infection rates in the world.
  10. During the notorious 1918 influenza pandemic, the use of face masks among the general population was widespread and in some places mandatory, but they made no difference.

F) The facemask aerosol issue

In the following video, Dr. Theodore Noel explains the facemask aerosol issue. (Source)

G) Studies claiming face masks are effective

Some recent studies argued that face masks are indeed effective against the new coronavirus and could at least prevent the infection of other people. However, most of these studies suffer from poor methodology and sometimes show the opposite of what they claim to show.

Typically, these studies ignore the effect of other measures, the natural development of infection rates, changes in test activity, or they compare places with different epidemiological conditions. Studies performed in a lab or as a computer simulation often aren’t applicable to the real world.

An overview:

  1. meta-study in the journal Lancet, commissioned by the WHOclaimed that masks could reduce the risk of infection by 80%, but the studies considered mainly N95 respirators in a hospital setting, not cloth masks in a community setting, the strength of the evidence was reported as “low”, and experts found numerous flaws in the study. Professor Peter Jueni, epidemiologist at the University of Toronto, called the WHO study “essentially useless”.
  2. A study in the journal PNAS claimed that masks had led to a decrease in infections in three global hotspots (including New York City), but the study did not take into account the natural decrease in infections and other simultaneous measures. The study was so flawed that over 40 scientists recommended that the study be withdrawn.
  3. US study claimed that US counties with mask mandates had lower Covid infection and hospitalization rates, but the authors had to withdraw their study as infections and hospitalizations increased in many of these counties shortly after the study was published.
  4. A large study run in Bangladesh claimed that surgical masks, but not cloth masks, reduced “symptomatic SARS-CoV-2 infections” by 0.08% (ARR), and only in people over 50. But a subsequent re-analysis of the study by statisticians found that there was in fact no benefit at all. According to one reviewer, the Bangladesh study was designed so poorly that it “ended before it even began”.
  5. German study claimed that the introduction of mandatory face masks in German cities had led to a significant decrease in infections. But the data did not support this claim: in some cities there was no change, in others a decrease, in others an increase in infections (see graph below). The city of Jena was an ‘exception’ only because it simultaneously introduced the strictest quarantine rules in Germany, but the study did not mention this.
  6. A review by the University of Oxford claimed that face masks are effective, but it was based on studies about SARS-1 and in health care settings, not in community settings.
  7. A review by members of the lobby group ‘Masks for All’, published in the journal PNAS, claimed that masks are effective as a source control against aerosol transmission in the community, but the review provided no real-world evidence supporting this proposition.
  8. A study published in Nature Communications in June 2021 claimed that masks reduced the risk of infection by 62%, but the study relied on self-reported online survey results and various modelling assumptions, not on actual measurements.
  9. A meta-study published in BMJ claimed face masks reduced infections by 53%, but the meta-study was based on seven low-quality observational studies. In response, the BMJ published an editorial acknowledging the “lack of good research” and the implausibility of the result.
  10. A German study, published in PNAS, claimed that N95/FFP2 masks are highly effective against coronavirus infections, but the study consisted only of a mathematical model without any real-world or lab data (see section D above).
  11. A study published by the US CDC claimed that face masks reduced covid infections in schools, but when the study was updated with more data, the effect disappeared.
  12. A study published in PNAS acknowledged that mask mandates weren’t effective, but claimed that mask wearing was effective. But the study relied on unvalidated self-reporting and modelling, not on actual data, and covered only the period from May to September 2020.

The annex of the German Jena study showed that face masks weren’t effective:


Mandatory masks in German cities: no relevant impact. IZA 2020

H) Risks associated with face masks

Wearing masks for a prolonged period of time may not be harmless, as the following evidence shows:

  1. The WHO warns of various “side effects” such as difficulty breathing and skin rashes.
  2. South Korean study, published in May 2023, found that N95 masks can release toxic volatile organic compounds (TVOC) at levels eight times higher than considered safe.
  3. A Japanese study, published in Nature Scientific Reports, found a significant number of bacteria and fungi on face masks, including some pathogenic microbes.
  4. An Israeli-Canadian study, published in Cognitive Research in February 2022, found that “face masks disrupt holistic processing and face perception in school-age children”.
  5. An Italian study using real-time capnography found that face masks and N95/FFP2 masks increased CO2 levels in inhaled air to levels above the acceptable exposure threshold.
  6. A study conducted by the University Hospital of Leipzig in Germany found that surgical masks and N95 masks significantly reduce the resilience and performance of healthy adults.
  7. The Hamburg Environmental Institute warned of the inhalation of chlorine compounds in polyester masks as well as environmental issues in connection with face mask disposal.
  8. The European rapid alert system RAPEX has already recalled over 100 mask models because they did not meet EU quality standards and could lead to “serious risks”.
  9. A study by the University of Muenster in Germany found that on N95 (FFP2) masks, Sars-CoV-2 may remain infectious for several days, thus increasing the risk of self-contamination.
  10. In China, several children who had to wear a mask during gym classes fainted and died; autopsies found a sudden cardiac arrest as the probable cause of death. In the US, a car driver wearing an N95 (FFP2) mask fainted and crashed due to CO2 intoxication.

Video: A mask-wearing, 19-year-old US athlete collapsed during an 800-meter run (April 2021):

I) Conclusion

Face masks in the general population might be effective, at least in some circumstances, but there is currently little to no evidence supporting this proposition. If the coronavirus is primarily transmitted via indoor aerosols, face masks are unlikely to be protective. Thus, health authorities should not assume or suggest that face masks will reduce the rate or risk of infection.

United States: mask mandates without benefit


United States: mask mandates without benefit (IanMSC)

Postscript (August 2021)

A long-term analysis shows that infections have been driven primarily by seasonal and endemic factors, whereas mask mandates and lockdowns have had no discernible impact (charts: IanMSC).

The Face Mask Folly in Retrospect


It has been known for decades that face masks don’t work against respiratory virus epidemics. Why has much of the world nonetheless fallen for the face mask folly?  Twelve reasons.

1) The droplet model

Many health authorities have relied on the obsolete ‘droplet model’ of virus transmission. If this model were correct, face masks would indeed work. But in reality, respiratory droplets – which by definition cannot be inhaled – play almost no role in virus transmission. Instead, respiratory viruses are transmitted via much smaller aerosols, as well as, possibly, some object surfaces. Face masks don’t work against either of these transmission routes.

2) The Asian paradox

During the first year of the pandemic, several East Asian countries had a very low coronavirus infection rate, and many health experts falsely assumed that this was due to face masks. In reality, it was due to very rapid border controls in some countries neighboring China as well as a combination of metabolic and immunologic factors reducing transmission rates. Nevertheless, many East Asian countries eventually were overwhelmed by the coronavirus, too (see charts below).

3) The Czech mirage

In the spring of 2020, the Czech Republic was one of the first European countries that introduced face masks. Because the Czech infection rate initially stayed low, many health experts falsely concluded that this was due to the masks. In reality, most of Eastern Europe simply missed the first wave of the epidemic. A few months later, the Czech Republic had the highest infection rate in the world, but by then, much of the world had already introduced face mask mandates.

4) Fake science

For decades, studies have shown that face masks don’t work against respiratory virus epidemics. But with the onset of the coronavirus pandemic and increasing political pressure (see below), suddenly studies appeared claiming the opposite. In reality, these studies were a mixture of confounded observational data, unrealistic modelling and lab results, and outright fraud. The most influential fraudulent study certainly was the WHO-commissioned meta-study published in The Lancet.

5) Asymptomatic transmission

Another factor contributing to the implementation of mask mandates was the notion of ‘asymptomatic transmission’. The idea was that everybody should be wearing a mask because even people without symptoms might spread the virus. The importance of asymptomatic and pre-symptomatic transmission is still a matter of debate – up to half of all transmission might occur prior to symptom onset –, but either way, face masks simply don’t work against aerosol transmission.

6) Political pressure

Several political factors contributed to the implementation of mask mandates. First, some politicians simply wanted to “do something” against the pandemic; second, some politicians thought face masks might have a “psychological effect” and might “remind” citizens to stay cautious (if anything, it had the opposite effect: creating a ‘false sense of security’); third, some politicians used mask mandates to enforce compliance and pressure the population into accepting mass vaccination.

In addition, there was a vicious circle involving science and politics: politicians claimed to “follow the science”, but scientists followed politics. For instance, the WHO admitted that their updated mask guidelines were in response to “political lobbying”, not new evidence. The most influential lobby group was “Masks For All”, founded by a “Young Leader” of the World Economic Forum (WEF).

7) The media

Perhaps unsurprisingly, most of the ‘mass media’ amplified the fraudulent science and the political pressure driving mask mandates. Only some independent media outlets and some truly independent experts questioned the validity of the underlying evidence. However, their voices got suppressed as dubious “fact checking” organizations eagerly enforced official guidelines and throttled or censored many articles and videos critical of face masks.

8) “Surgeons wear masks”

Surgeons wear masks, so they must be effective, right? This was another notion contributing to the face mask misunderstanding. In reality, surgeons wear masks not against viruses, but against much larger bacteria, but more importantly, studies have long shown that even surgeons’ masks make no difference in terms of bacterial wound infections.

9) “Masks suppressed the flu”

“Masks suppressed the flu, so they obviously work.” This was another very common claim in favor of masks. While it is true that the flu (i.e. influenza viruses) disappeared in the spring of 2020 and remained absent throughout the coronavirus pandemic, masks had nothing to do with it.

This is evident as the flu disappeared even in states without masks, lockdowns and school closures – such as Sweden, Florida and Belarus – while the flu hadn’t disappeared during earlier flu epidemics and pandemics, despite widespread mask use (e.g. during the 2019 flu epidemic in Japan).

Instead, influenza viruses disappeared globally because they were temporarily displaced by the more infectious novel coronavirus (so-called viral interference, known from previous pandemics); for the same reason, new coronavirus variants repeatedly displaced existing variants, often within weeks. Indeed, in countries that had reached very high levels of population immunity against the coronavirus, the flu returned by summer 2021 (e.g. in India at 80% population immunity).

10) Misleading memes

To convince low-IQ social media users of the effectiveness of face masks, several unscientific memes were created. The most notorious one probably was the “peeing into your pants” meme, shared by many ‘health experts’ (really). Many of these memes exploited the fact that most people simply don’t realize how small and ubiquitous viral aerosols really are.

11) Doubling down

After mask mandates had been implemented globally and billions of dollars had been spent on masks, it soon became obvious – once more – that masks simply don’t work against respiratory virus epidemics (see charts below). But at that point, neither politicians, nor ‘health experts’, nor duped citizens who had to wear them for months wanted to admit this anymore.

Instead, some ‘health authorities’ doubled down and enforced outdoor masking (even on beaches), double-masking, or N95/FFP2 masking, to no avail. The one novel scientific insight produced during the coronavirus pandemic was that even N95/FFP2 mask mandates have made no difference at all.

12) Sweden: The exception that proved the rule

Only very few countries in the world have resisted the face mask folly. The most famous example is probably Sweden (see charts below), which has also resisted the lockdown experiment. Naturally, Swedish coronavirus mortality has remained below the European average. But the many vicious attacks against Sweden by much of the international media showed just how difficult it has been to escape the global madness and follow the real science during this bizarre pandemic.

How face masks and lockdowns failed

The following charts show that infections have been driven primarily by seasonal and endemic factors, whereas mask mandates and lockdowns have had no discernible impact (chartsIanMSC).

“The more masks fail, the more we need them.” (IanMSC)

Resource for this article:  swprs.org/face-masks-evidence/