Does the Molekule Air Purifier Live Up to the Hype?

    CR tested the air purifier everyone’s talking about—and recommends three better alternatives

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    person holding smartphone with Molekule app in front of Molekule air purifier Photo: Consumer Reports

    Maybe you’ve seen the ads for the Molekule Air in your social media feeds: the sleek, cylindrical air purifier set inside a clean, minimalist home. Amid calming mint-green graphics are claims that it’ll destroy the harmful molds, viruses, bacteria, and gaseous chemicals lurking in the air you breathe at home. 

    Like so many brands that trend on social media, the Molekule Air is available only through the manufacturer’s website—for a whopping $800. It’s the sort of niche product that we wouldn’t necessarily test, but given the buzz it has generated, we felt a responsibility to weigh in with test data.

    And because the Molekule manufacturer claims to have revolutionized air cleaning with its proprietary PECO technology, we dug a little deeper. Here’s the story of our reporting and our lab tests.

    What Is PECO?

    This acronym is short for photoelectrochemical oxidation. It isn’t new technology, per se, but rather a boosted version of PCO (photocatalytic oxidation), which has been used for decades to clean contaminated air and water. 

    A typical mesh filter—HEPA, for instance—captures only airborne particles. PECO and PCO, however, take it one step further and also target gases. It does this by coating filters in a catalyst (PCO usually uses titanium dioxide) that reacts with UV light to oxidize gaseous pollutants and breaks them down into harmless molecules.

    For more on air purifiers and how to shop for one, check CR’s air purifier ratings and buying guide.


    According to the Environmental Protection Agency, PCO air cleaners can break down many types of gaseous pollutants, but not many typically found in indoor air. The process can also react with some pollutants to generate other dangerous byproducts, such as ozone, formaldehyde, nitrogen dioxide, and carbon monoxide.

    Because of these factors, the EPA reports that to effectively and efficiently eliminate common gases and microbes found in homes in a safe manner, PCO technology needs to improve. Molekule says it has done just that.

    “PCO was inefficient in destroying pollutants, so we fine-tuned all the parameters,” says Jaya Rao, Molekule’s chief operating officer and co-founder. “PECO innovations happened on many levels: the chemical coating, the filter, as well as the UV lighting.” Working together, she says, these innovations make PECO work faster and more efficiently than PCO, allowing it to destroy gases, bacteria, viruses, and mold spores—without producing any harmful byproducts. Rao declined to go into detail about what the company uses for the catalyst.

    CR tests for particle reduction and not for gas or microbe removal. So we asked James Dickerson, CR’s chief scientific officer, whether Molekule’s claims have any merit.

    “Theoretically, PECO could work to eliminate microscopic airborne molecules,” Dickerson says. “But our tests show that the Molekule Air is not proficient at catching larger airborne particles, which ultimately means it’s not getting enough air passing through the system.”

    Molekule Air Test Results

    We put the Molekule Air through our standard battery of air purifier tests, and it almost flunked: We put it into a sealed chamber and injected particles as small as 0.1 micron and up to 1 micron into the room—a range that includes dust mite allergens, cat allergens, smog, smoke, and atmospheric dust. (For reference, human hair has a diameter of 100 microns). A particle counter measured the change in air-particle concentration as the machine ran for 15 minutes. As usual, we tested at the highest speed and again at a lower speed.

    Both the Molekule Air and its larger, newer sibling, the Molekule Air Pro, lag behind similarly priced and similarly stylish alternatives. The Molekule Air gets a Fair rating for smoke and dust removal at high speed and a Poor—the lowest score possible—at low speed. It is the seventh-lowest-scoring air purifier of the 105 in our tests. The larger Molekule Air Pro did better at its highest setting, but this is tempered by its extremely high noise level at high speed and its even higher price. The manufacturer says the Molekule Air is sized for rooms up to 600 square feet, but its performance in our tests ranks it among compact models that are designed for small rooms. Based on our lab’s calculated rate at which it can process the air, the Molekule Air wouldn’t be able to handle any room larger than 100 square feet.

    We shared our methodology and findings with Rao, and she took issue with our testing.

    “It’s a very limited assessment of Molekule because instantaneous removal of particles is not the full picture of what air purification looks like,” Rao says. “And while we may be destroying at a slower rate, we’re still doing something much more complicated, which is truly purifying the air at the nanoscale level and making it safer.”

    But if the Molekule Air isn’t pulling enough air into the machine in the first place, it may struggle to clean the air at any scale. 

    “Even if the PECO filter works and it purifies the air of microscopic particles, it’s still not effectively catching the large particles, which are also irritants,” Dickerson says.

    In addition to the Molekule Air’s poor performance in our testing for particle reduction, there’s the price to consider. The Molekule Air costs $800, with an annual cost of $130 for filter replacements, plus an additional $50 per year for energy use, based on our calculations. (The model is not Energy Star certified, unlike the majority of air purifiers we test.) The Molekule Air Pro goes for around $1,000, and also isn’t Energy Star certified, leading to a combined annual cost of more than $375.

    Even the smaller, less powerful Molekule Air isn’t very quiet, garnering a Fair score for noise on the high-speed setting and a Good score on the low-speed setting.

    Our verdict? Pass on either Molekule and opt for one of CR’s recommended air purifiers.

    Here are three models, listed in alphabetical order, that perform well in our particle removal tests and cost hundreds less.

    Editor’s Note: This article, originally published Oct. 25, 2019, was updated Dec. 9, 2019, to clarify our expert’s critique of the Molekule Air.

    Headshot of Perry Santanachote, editor with the Home editorial team at Consumer Reports

    Perry Santanachote

    I cover the intersection of people, products, and sustainability, and try to provide humorous but useful advice for everyday living. I love to dive deep into how things work, and debunking myths might be my favorite pastime. But what I aim to be above all else is a guiding voice while you're shopping, telling you what's a value, what's a rip-off, and what's just right for you and your family.