Hypochlorous Acid Mists Are Touted as Cure-Alls. So We Tested Them.

New York Times

01-05-2025

Hannah Frye/NYT Wirecutter
Once we understood the science of hypochlorous acid, we put seven of the most popular, sought-after hypochlorous acid mists to the test. In many cases the ingredients lists look nearly identical (pretty much just water, salt, and hypochlorous acid). But the ratio of those ingredients and the formula's pH (or acidity level) are what made one product different from the next.
We compared their formulas, and for testing we selected mists with minimal ingredients and formulations that are considered safe to use on scrapes, makeup tools, and the face. This eliminated some mists that had hypochlorous acid as just one of several skin-care ingredients, including things like salicylic acid, peptides, fruit extracts, and added fragrance.
Our testing list included:
Our testing panel included six people with varying skin types, and they tested these products in Wirecutter's office. Testers evaluated each mist for its first-impression user experience, including the pump, the feel of the mist, how it performed over makeup, the packaging, and the smell.
Next, we considered price and formula, including acidity and concentration. Of the seven mists we tested, we were able to confirm that four had both ideal acidity and concentration.
The concentration of HOCl in products made for skin tends to fall between 0.01% to 0.02% hypochlorous acid (the rest of the spray is typically a mix of water and salt). Rambhia said this concentration is a 'sweet spot' in that it's strong enough to disrupt pathogens but mild enough for good bacteria to withstand. (This is one reason why you don't need to worry that hypochlorous acid sprays made for the skin will disrupt your skin's microbiome or kill off good bacteria.) Of the mists we tested, our two favorites fall within this range. Some brands, like Prequel, put the concentration of hypochlorous acid on the bottle. Hannah Frye/NYT Wirecutter
The next thing to consider is pH, or acidity. Some studies (including one from 2022 and another from 2023) suggest that for a hypochlorous acid product for use on skin, the ideal pH should fall roughly between 4 and 6 (similar to the pH of the skin's acidic mantle) to be the most effective for killing bacteria. And Tran and Bowles both agreed. That acidic mantle is a pH of about 4.5 to 5.5, so 'products in this acidic range better support skin's natural defenses,' Tran said.
However, if the formula is too acidic, and the pH falls below about 4, this may cause the hypochlorous acid solution to lose stability and convert to chlorine gas, Tran said. On the flip side, when pH surpasses about 6, some of the hypochlorous acid could convert to hypochlorite ion, a form research suggests is less effective at killing bacteria. Some brands list pH and concentration information on the bottle or online. For those that didn't, I reached out to the brands directly.
One spray stood out to our panel as a favorite in ideal formula, usability, and value: Personal Day Trust Me on This Hypochlorous Acid Spray. The mists that won over our testers. Marki Williams/NYT Wirecutter
Adored for its fine mist and beautiful packaging, this spray took the cake for our testers. We also liked that it didn't leave a potent chlorine-like smell.
Personal Day Trust Me on This Hypochlorous Acid Spray is a relative newcomer to the hypochlorous acid scene (it launched in March 2025), and it lands in the middle of the pack on price (at $6.75 an ounce, or $27 for a bottle, at time of writing). Our panel gave it high praise for its super-fine mist, which refreshed our testers' skin without making it feel too wet. I used the Personal Day mist over my makeup multiple times throughout testing, and it never displaced foundation or concealer, even with a generous amount of spritzing.
The dilution, as told to me by the company, is 0.02%, which falls into the acceptable range for use on the skin. The pH is between 5.3 and 5.7, falling into that expert-approved window.
The mist had little to no detectable scent, and all of the testers admired the packaging. Staff writer Caroline Mullen commented, 'It has a hefty weight, smooth rounded edges, and an almost flocked feeling that pleased me. Plus, I'm eternally into a bright green.'
This spray earned high praise for its gentle mist and pretty packaging. Some testers initially didn't love the light chlorine smell, but the scent faded quickly.
The Prequel Universal Skin Solution Dermal Spray was our next favorite. Like the Personal Day spray's mist, this one's fine mist hit the skin gently, not wetly. One tester remarked, 'The small packaging is so pretty, and it's easy to hold and spray.' However, some testers detected a stronger, pool-like scent from the Prequel spray in comparison with Personal Day's mist.
The Prequel spray has the same dilution as the Personal Day spray: 0.02% hypochlorous acid, as stated on the bottle, and a pH of 5.5, as listed on the website. On the Prequel spray's ingredients list, you'll also find muriatic acid (aka hydrochloric acid), which Bowles said is used in diluted amounts to help lower the pH of the product. 'By doing so, it helps optimize the hypochlorous acid's effectiveness in killing bacteria and promoting healing,' she explained.
Prequel's mist also has a seal of acceptance from the National Rosacea Society; this indicates that a product has undergone testing and consideration specifically for those who struggle with rosacea, and that it should be free from ingredients commonly known to exacerbate rosacea symptoms. So if you have rosacea, you may consider this seal to be a plus.
Our testers considered the Prequel spray to be in a dead heat with the Hydrinity Hyacyn Active mist ($20 an ounce, or $60 a bottle, at the time of writing), which delivered a similar user experience. However, we couldn't justify the Hydrinity spray's price, so we dismissed it. The middle-ground mist we found to be slightly less satisfying than our winners. Marki Williams/NYT Wirecutter
This mist earned praise for its mild, chlorine-like smell and lightweight packaging (which makes it nice for traveling). Yet it lost points for having a messy mist and a cheap-feeling bottle (given the price).
We liked, but didn't love, the popular Tower28 SOS Rescue Spray. Although many testers enjoyed the look of the packaging, they said they found the mist to be a tad too damp. Editor Hannah Rimm said the Tower28 mist 'was very wet so I didn't want to put it on my face.' She added, however, that it felt refreshing on her body. Staff writer Maki Yazawa, who has used the Tower28 mist before, said, 'For $28, I'd expect a much finer mist, and the packaging feels cheaply made.' Some testers found the chlorine-like smell to be mild, but others disagreed.
Tower28's spray lists a pH of 4.5. We confirmed with the brand that its dilution falls within the ideal range of 0.01% to 0.02% hypochlorous acid, though Tower28 declined to disclose the exact percentage. This nondisclosure isn't necessarily a red flag, Tran explained, since some brands guard their formulations for competitive reasons. She added that Tower28 obtained some relevant certification seals (like the acceptance seals from the National Eczema Association and the National Rosacea Society), which are 'positive indicators of their product's safety and testing standards.' These are our testers' least favorite mists in terms of smell, feel, and packaging. Marki Williams/NYT Wirecutter
The mists our panel least liked using — E11ement Hypochlorous Acid Face and Skin Spray, SkinSmart Facial Cleanser for Acne, and Magic Molecule The Solution — coincidentally all have a pH of 7 or above, according to the brands, though their concentrations fall within the ideal range.
Hypochlorous acid mists with a pH of 7 or higher could still offer some benefits, but they might not be as effective at killing bacteria over time, Bowles said. She said this is especially true if you're hoping to use one of these sprays to help treat an inflammatory skin condition.
SkinSmart and Magic Molecules HOCl sprays are FDA-cleared, which is not required, and ultimately this may not be the most important factor to consider. 'What really matters is the formulation itself — particularly the pH,' Bowles said. 'A low-pH mist without FDA clearance can actually be more beneficial for skin care than a high-pH, FDA-cleared formula that isn't optimized for the skin's needs.'
Our least favorite mists had clumsier, wetter mists and strong (if fleeting) pool smells, and they were, unfortunately, also the most affordable options. If price is paramount, your skin may still see some benefits from these mists, but you could be compromising in other areas.