Is Wearing Three Masks Better Than One?

Analysis by Dr. Joseph Mercola Fact Checked

Story at-a-glance

  • In order to “maximize protection” against COVID-19, researchers recommended layering two types of masks or using a three-layer mask to keep particles out
  • There’s just one pesky problem to covering your mouth and nose with multiple layers of material: “At some point, ‘we run the risk of making it too hard to breathe’”
  • In the included video, Dr. Ted Noel uses a vaping device and several different types of masks — including disposable and cloth — to illustrate that vapor clearly passes around and through the masks
  • The first randomized controlled trial of the effectiveness of surgical face masks against SARS-CoV-2 infection found masks did not statistically significantly reduce the incidence of infection
  • Researchers writing in PeerJ said cloth masks have “poor filtering efficiency” due to large, open pores present in the masks; this got even worse after washing, with filtering efficiency dropping by 20% after the mask was washed and dried four times


This is an older article that may not reflect Dr. Mercola’s current view on this topic. Use our search engine to find Dr. Mercola’s latest position on any health topic.

In the video above, Dr. Ted Noel is among the latest to use common sense and reason to argue that masks don’t work to stop aerosol virus transmission. He uses a vaping device and several different types of masks — including disposable and cloth — to illustrate his point, as the vapor clearly passes around and through the masks.

“Aerosols will not be stopped by masks,” he says. “You don’t need a big study. All you need is this [holding up a vaping apparatus]. The [vape] aerosol is actually larger in molecular size than the aerosol from your breath,” yet it still passes easily through the mask.

This demonstration provides visual evidence that masks may be useless against SARS-CoV-2, the virus that causes COVID-19, but if you’re looking for further support, a growing number of studies comparing U.S. states with mask mandates to those without mandates suggest the same.1

Are Double, or Triple, Masks Needed?

If one mask isn’t enough, The New York Times suggested in January 2021 that perhaps doubling up would offer better protection. “Double-masking isn’t necessary for everyone,” the Times wrote. “But for people with thin or flimsy face coverings, ‘if you combine multiple layers, you start achieving pretty high efficiencies’ of blocking viruses from exiting and entering the airway.’”2

They cited commentary by Linsey Marr of Virginia Tech, which recommended layering two types of masks or using a three-layer mask to keep particles out.3

There’s just one pesky problem. “At some point, ‘we run the risk of making it too hard to breathe,’ she said.” If you can get past that trade-off, the rationale seems to be that if you add enough layers of material, infectious droplets must travel through an obstacle course of sorts, and eventually you’ll stop something from getting through.

Marr and co-author Monica Gandhi from the University of California said that in studies of dozens of mask materials, filtration effectiveness ranged from less than 10% (for polyurethane foam) to nearly 100% for a vacuum cleaner bag. But in tests on humans wearing homemade masks, they were only 50% to 60% effective at protecting the wearer from pollution particles.4

Based on their own studies, Marr and Gandhi said they recommend “a high-quality surgical mask or a fabric mask of at least two layers with high thread count for basic protection,” but for “maximal protection,” doubling up on masks or using a triple-layer variety is necessary:5

“For maximal protection, members of the public can either (1) wear a cloth mask tightly on top of a surgical mask where the surgical mask acts as a filter and the cloth mask provides an additional layer of filtration while improving the fit; or (2) wear a three-layer mask with outer layers consisting of a flexible, tightly woven fabric that can conform well to the face and a middle layer consisting of a non- woven high-efficiency filter material (e.g., vacuum bag material).

If the masks fit well, these combinations should produce an overall efficiency of >90% for particles 1 µm and larger, which corresponds to the size of respiratory aerosols that we think are most important in mediating transmission of COVID-19.”

But layering up on masks that provide good filtration, or wearing more than two masks at once, may have diminishing returns, the Times noted, again highlighting the obvious that covering your mouth and nose with multiple layers of fabric and filtration material could “make it much harder to breathe normally.”6

COVID-19 Spreads Via Aerosolized Particles

There’s growing evidence that aerosol transmission is involved in the spread of SARS-CoV-2,7 which are 0.125 μm in size. September 18, 2020, the CDC posted updated COVID-19 guidance on its "How COVID-19 Spreads" page that, for the first time, mentioned aerosol transmission of SARS-CoV-2, saying "this is thought to be the main way the virus spreads."8

The CDC then deleted the mention of aerosols and the possibility of spread beyond 6 feet the following Monday, September 21, saying a draft version of proposed changes had been posted "in error."9

It’s a noteworthy difference, because if SARS-CoV-2 is spread via aerosolized droplets, which research suggests,10 such droplets remain in the air for at least three hours and can travel over long distances of up to 27 feet.11 This adds to the likelihood that cloth masks do little to stop you from getting COVID-19. AAPS explained:12

“The preponderance of scientific evidence supports that aerosols play a critical role in the transmission of SARS-CoV-2. Years of dose response studies indicate that if anything gets through, you will become infected. Thus, any respiratory protection respirator or mask must provide a high level of filtration and fit to be highly effective in preventing the transmission of SARS-CoV-2.”

Face Masks Don’t Reduce COVID-19 Infection Rate

The first randomized controlled trial of more than 6,000 individuals to assess the effectiveness of surgical face masks against SARS-CoV-2 infection found masks did not statistically significantly reduce the incidence of infection.13 Among mask wearers, 1.8% ended up testing positive for SARS-CoV-2, compared to 2.1% among controls.

When they removed the people who did not adhere to proper mask use, the results remained the same — 1.8%, which suggests adherence makes no significant difference. Among those who reported wearing their face mask “exactly as instructed,” 2% tested positive for SARS-CoV-2 compared to 2.1% of the controls.

A case-control investigation of people with COVID-19 who visited 11 U.S. health care facilities also showed little benefit of mask usage. The U.S. Centers for Disease Control and Prevention report revealed factors associated with getting the disease,14 including the use of cloth face coverings or masks in the 14 days before becoming ill.

The majority of them — 70.6% — reported that they “always” wore a mask, but they still got sick. Among the interview respondents who became ill, 108, or 70.6%, said they always wore a mask, compared to six, or 3.9%, who said they “never” did, and six more, or 3.9%, who said they “rarely” did.

In other words, of the symptomatic adults with COVID-19, 70.6% always wore a mask and still got sick, compared to 7.8% for those who rarely or never did.15 Further, the cloth masks most of the public are wearing may have a pore size of 80 to 500 μm,16 which is far larger than viruses or even respiratory droplets, which range from 5 to 10 μm.17

Researchers writing in PeerJ said such masks have “poor filtering efficiency” that “may have arisen from larger and open pores present in the masks.” This got even worse after washing, with filtering efficiency dropping by 20% after the mask was washed and dried four times.18

Policy Review: Face Masks Don’t Affect Flu Transmission

In May 2020, researchers reviewed the evidence of nonpharmaceutical personal protective measures against pandemic influenza, including 10 studies that analyzed the effectiveness of face masks in reducing flu virus infections in the community. “We found no significant reduction in influenza transmission with the use of face masks,” they wrote,19 citing the following research:

  • During the Hajj pilgrimage in Australia, no significant difference in influenza infection was found among those who wore a mask and those who did not20
  • Two studies of university students living in residence halls found no significant reduction of influenza cases among the face mask groups21,22
  • In a study of flu transmission among households, face mask usage did not lead to a significant reduction in secondary flu virus infection23

While the researchers suggested there could be some benefit from wearing tight-fitting respirators that are properly fit-tested, loose-fitting face masks, such as disposable masks, are much less likely to offer protection and could even increase the risk of transmission with improper use:24

“There is limited evidence for their effectiveness in preventing influenza virus transmission either when worn by the infected person for source control or when worn by uninfected persons to reduce exposure. Our systematic review found no significant effect of face masks on transmission of laboratory-confirmed influenza.”

COVID-19 Cases Higher in Areas With Mask Mandates

Widespread mask mandates were rolled out despite a lack of solid evidence to support their use among the general population. In an attempt to add some science into the equation, computer scientists, actuaries and data analysts from Rational Ground25 looked at COVID-19 cases from May 1, 2020, to December 15, 2020, in all 50 U.S. states.

They calculated how many cases per day occurred by population with and without mask mandates.26 Among states without a mask mandate, 5,781,716 cases were counted over 5,772 days. This works out to:27

  • No mask mandates: 17 cases per 100,000 people per day
  • Mask mandates: 27 cases per 100,000 people per day

In short, COVID-19 cases were higher with mask mandates than without. As noted by Daniel Horowitz, a senior editor of The Blaze:28

“We can turn the numbers upside down and inside out, but no matter how we examine them, there is no evidence of masks correlating with reduced spread. If anything, the opposite is true … It's self-evident that the virus does what it does naturally and follows a very mechanical pattern regardless of state policies …”

A working paper released by the National Bureau of Economic Research29 concurred, finding that for all the countries and U.S. states studied, once the region experienced 25 cumulative COVID-19 deaths, the growth rates of daily COVID-19 deaths fell from initially high levels to close to zero within 20 to 30 days.

This occurred regardless of what type of nonpharmaceutical interventions, including mask mandates, travel restrictions, stay-at-home orders, quarantines and lockdowns, were put in place. “[T]hose policies have varied in their timing and implementation across countries and states, but the trends in outcomes do not,” the American Institute for Economic Research reported.30

Do You Have to Wear a Mask?

Many people believe that wearing a mask should be an individual choice, but a majority of U.S. states and cities have made mask-wearing mandatory. Some private businesses have done so as well. This isn’t necessarily a case of “wearing something is better than nothing,” as some research suggests mask usage could lead to physical and psychological harm.31

The U.S. nonprofit Stand for Health Freedom is among those calling for peaceful civil disobedience against mandatory masks, and has a widget you can use to contact your government representatives to let them know wearing a mask must be a personal choice.

While you may be forced to wear a mask in order to enter certain places of business, if you live in an area with a mask mandate there is usually a caveat that states “unless you can maintain a 6-foot distance.” If you can maintain this distance, you can forgo a mask and still comply with the mandate.


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