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What our customers report in just 3 weeks:
Backed by scientific research, our naturally antibacterial ingredients help improve oral care by fighting bad bacteria and reducing plaque buildup all while polishing and remineralizing teeth.
Fueled By Powerful Ingredients
Chew 1-2 pieces after meals for at least 30 minutes or as long as you’d like
Chewing for long work days is encouraged!
How long does it last? One pack should last for one week. A four-pack is approximately a 30-day supply if you chew 2 pieces per day.
When can I expect to see results?Results may vary, but most customers report results within the first three weeks. Many report a cleaner-feeling mouth and smoother teeth after chewing their first piece.
Processes in 1-3 days. Delivery times may vary depending on the carrier.
OVER 56k+ UNDERBRUSH FANS
"Cleans my teeth and tastes delicious!"
CHEW WITH PURPOSE NOT POISON
Enjoy the multi-functional ingredients your mouth needs and the planet deserves without the garbage Big Gum brands use.
Overall rating: 4.7729673 / 5 from 15522 reviews.
Customers report a cleaner mouth and fresher breath after using the Remineralizing Gum. They appreciate its long-lasting chew and natural ingredients, though some find the flavor doesn't last long. The packaging is praised for being environmentally friendly.
Review topics: [smell, feel, packaging, issues, husband, teeth, texture, shipping, ingredients, mouth, quality, price, customer service, consistency, benefits, flavor, alternative, box, improvement, gum, results, sugar, effects, chew, size, pain, touch, buy, plastic, amount].
"We chose the four flavor collection. Sadly the cinnamon was disappointing. The cinnamon was mild and dissipated immediately leaving an unpleasant taste. The other three flavors have been great. I was pleasantly surprised how long the taste lasted and the gum remained soft and easy to chew. My teeth feel clean after chewing and my breath is fresher."
"Feels health and high quality. Recommended to friends. Flavor doesn't last that long but then you can taste the natural gum flavor. Can be chewed for a long time! I stop when my jaw gets tired, but the gum never breaks down in your mouth. My favorite it Cinnamon- well balanced, so much better than those artificial flavored gums. I'm not normally a big cinnamon fan."
"I live in Australia so exchange currency makes it more expensive. I have tried nearly all similar products and found Underbrush remineralizing gum the most true product on the market. Don't be scammed by other Chinese counterfeit products sold on Amazon like I was . Yeah it costs a bit more but your getting a genuine quality gum that actually says what it really is. Looking forward to my next order!"
"I’m loving this and I’m noticing the difference in my teeth! They don’t hurt when I eat ice cream or chew cold foods, but sadly, I’m allergic to all things pine and pine related… so I’m chewing away happily and I can’t figure out why I keep getting canker sores… sadly it’s been isolated to the gum. 😔"
"Honestly, a great investment for my health, absolutely satisfied with this gum. I also notice a change in quality for the better, overall great. My teeth feel stronger, I can feel where the remineralization is happening, and my mouth feels so clean; Flavor is not overpowering, lasts longer than the last batch I got. 10/10"
"Every piece i've chewed so far has been fantastic! This product is well worth the hype and worth the slightly extra cost at no expense to the ingredient quality! My teeth do feel healthier and my breathe does seem to not get as bad likely due to the ingredients in your gum not killing beneficial bacteria. I do miss the honey bunn flavor, though i am enjoying the Tropical fruit! If I could make a couple suggestions, I'd like to see either a Watermelon or Pear flavor in the future without the use of artificial flavors and sweeteners."
"LOVING this gum. My teeth feel great. Not sure if it’s this or something else but they feel less sensitive for the first time ever. The jaw workout is great, it lasts a while and I feel clean after chewing. Very stoked about this product."
"For those on the fence about trying it... Just try it. I was afraid for a while based on other bad reviews from people who bought the cheap knockoff gums, but so far I've been happy with this gum since deciding to try the mint and cinnamon versions. There are pros and cons tho... And I can't give it a 5 star because it does have cons. Pros: - Has a nice outer shell coating texture similar to regular gum when you first bite into it, like Dentyn Ice. Was pleasantly surprised. - Chews like gum. I've chewed one piece for hours as a way to keep my mind focused. Didn't break down or degrade. - It's not too small like some reviews suggest. See pic next to an Ice Breaker cube and Cheez-It. It's not much different at all, aside from color being natural in comparison. - Supposedly helps with sensitivity, whitening, and rebuilding enamel.. I haven't been chewing long or consistent enough to notice a difference yet, but it's definitely not hurting anything. - I can chew this with my crowns. I have two in the back, top and bottom, and nothing has come flying off, felt loose, or otherwise made me feel like I shouldn't chew on that side of my mouth. - Nice flavors for both the mint and the cinnamon. I've never been a fruit gum person so had no desire to try those, but would love to see a spearmint and/or wintermint flavor release if that's even possible to offer naturally. - Made with natural ingredients. I love the idea of chewing on tree saps instead of plastic resin. Cons: - Price. Yes, this gum has benefits regular gum doesn't and it's worth it to me not to chew plastics and chemicals, however I still can't just chew this gum in whatever quantity I want like regular gum. I could chew several Ice Breakers for the cost of one piece of this. If you're looking for something to chew just for the sake of chewing and don't care about chemicals, stick to regular gum. - While the flavor is good, it's gone in 30 seconds or less. It just ends up tasting like pretty much nothing the longer you chew. I will still get micro hints of mint or cinnamon if I stop chewing for a minute and then start up again, but it doesn't hold flavor like chemical gum would. The benefits outweigh this con in my opinion tho. - Initial chew. It breaks apart into crumbles when you first start chewing, until you mash them with your teeth enough they come back together to form the gum. It can make it feel like maybe you got duped for a piece of candy but it's the nature of the ingredients I guess. I've found chewing on one side of the mouth, until it comes back together, works the best, otherwise I'm swallowing little pieces of gum crumbs by accident, or getting those crumbs stuck in the space between my lower lip and gums where it's hard to reach with your tongue, if that makes sense. - Not third party tested. I've read many studies showing that hydroxyapatite can contain toxic heavy metals depending on where it's sourced from, so there is potential risk with this gum. Would love for them to release an unbiased third party test proving their ingredients are truly safe to consume. Other neutral things noted: - The chewing firmness. I'm not sure what it is, but it's harder to chew at first around the time the flavor is gone, but if you keep chewing it, it's like your saliva or heat of your mouth breaks it down enough that it starts becoming softer like actual gum. I know I read some complaints about it being hard to chew, and I do experience this initially, but if I chew long enough this isn't the case anymore. Take this review as you will. I stopped chewing regular gum the second I found out what it was made with and was really sad to give it up, so I'll continue buying this gum because it gives a much healthier alternative with hopefully added benefits for my tooth enamel."
"This gum was slightly unexpected and surprising. I have found that one piece is in fact enough despite the size. The mastic mint flavor is very good and is soon replaced by the natural characteristics of the other gums used for production. I additionally view this as a feature. I will order this product again, I do feel that this supports my dental health and I appreciate the use of natural ingredients and intentionality of the product."
"I didn't typically chew gum, but I was curious about Underbrush after seeing the hype, so I ordered it - and now I chew it after every meal. It tastes good - even after the initial flavor burst is long gone. It also feels good - like I am chewing on something wholesome, rather than a wad of synthetic goop. My teeth feel cleaner, my breath is fresher. And I just ordered 4 more packs :)"
Most conventional sugar-free gums are designed to do two things: freshen breath and stimulate saliva flow.
Underbrush is formulated around a different goal — it pairs the saliva-stimulating benefit common to all chewing gum with a set of minerals and botanicals that have been studied in oral care research, including hydroxyapatite (in nano and micro particle sizes) and the sugar alcohol xylitol.
Chewing keeps these ingredients in contact with the teeth and oral environment for an extended window, typically when you're away from a toothbrush.
The functional chewing gum category has grown quickly for exactly this reason — consumers increasingly want products that fit into an oral care routine rather than just mask odor.
Underbrush is built to complement brushing and flossing between meals, not to replace them.
Learn more about what makes natural chewing gum different.
Every Underbrush flavor shares the same foundation: a chicle gum base (chicle, candelilla wax, citric acid), hydroxyapatite in both nano and micro particle sizes — a compound chemically similar to the primary mineral in tooth enamel — and a set of natural resins long used in oral care traditions, including mastic, spruce, myrrh, and acacia gum.
All flavors are sweetened with sugar alcohols rather than artificial sweeteners.
The flavors differ in their mineral and flavor profiles:
Mastic Mint carries the fullest mineral system, with hydroxyapatite plus calcium carbonate, magnesium carbonate, and zinc gluconate, finished with a natural mint terpene blend (menthone, carvone, cineol);
Berry includes the same broader mineral set along with real fruit powders (blackberry, raspberry, strawberry, dragon fruit), natural and organic flavors, and stevia extract;
Cinna Mastic features hydroxyapatite, Ceylon cinnamon — the lower-coumarin "true" cinnamon — a warm spice terpene blend (eugenol, cinnamaldehyde, humulene), and stevia extract.
Because formulations differ by variety, always check the full ingredient list on the specific product you're buying.
Yes — there is a growing body of published, peer-reviewed research on both xylitol and nano-hydroxyapatite in oral care contexts.
A 2025 narrative review published in the journal Biomimetics reviewed multiple studies evaluating hydroxyapatite in oral care applications and concluded that hydroxyapatite shows promise as a biomimetic ingredient for supporting enamel-focused oral care.
It's worth being transparent about the limits of this evidence: much of the existing research has been conducted on toothpastes and gels rather than chewing gum specifically, and product-specific clinical trials on nano-hydroxyapatite gum remain limited.
Chewing may provide prolonged ingredient contact with the oral environment compared with shorter-duration oral care products, although research on hydroxyapatite chewing gum specifically remains limited. Individual results may vary, and this product is not intended to diagnose, treat, cure, or prevent any disease.
These statements have not been evaluated by the U.S. Food and Drug Administration. We encourage you to consult your dentist or healthcare provider with any specific oral health concerns.
For further reading, see whether remineralizing gum is legit.
For the best experience, chew each piece for 15 to 20 minutes after meals or as desired throughout the day — this is roughly the window in which most chewing gum delivers its saliva-stimulating benefit and keeps the formulation in contact with the oral environment.
For hygiene purposes, we recommend replacing each piece every 48–72 hours if you set it aside between uses.
As with all oral care habits, consistency over time matters more than any single session.
Chewing after meals, when food particles and acids are most present in the mouth, is a practical time to use it.
Learn more about chewable mastic gum.
No. Underbrush is designed to complement — not replace — regular brushing, flossing, and professional dental care.
Think of it as a between-meal addition to an existing routine, especially useful in situations where brushing isn't immediately possible, such as after lunch at work or while traveling.
No chewing gum is a substitute for the mechanical cleaning that a toothbrush and floss provide, and none should be treated as one.
Always follow the oral hygiene recommendations of your dentist.
You may also be interested in natural approaches to tooth sensitivity.
Yes. Nathan & Sons gum is formulated without gluten, soy, dairy, artificial flavors, artificial colors, or artificial sweeteners. It's sweetened with sugar alcohols — xylitol and erythritol — and the Berry and Cinna Mastic flavors also include stevia extract, a naturally derived sweetener.
Formulations and individual sensitivities vary, so anyone with a known allergy or sensitivity should always review the full ingredient list on the specific product label before use.
The complete, current ingredient declaration is printed on the packaging and is also available on our official product listings.
Underbrush is built on a chicle gum base — a natural, tree-sap-derived base (chicle, candelilla wax, and citric acid) rather than the synthetic plastic-based polymers found in most conventional gums.
Chicle is the traditional chewing gum base harvested from the sapodilla tree, used long before petroleum-based gum bases became the industry standard.
The packaging is designed to be minimal and recyclable.
We strive to source ingredients responsibly and continually evaluate our sourcing practices, and we encourage customers to recycle in accordance with local guidelines.
Underbrush comes in three flavors built from natural sources rather than artificial enhancers.
Mastic Mint offers a fresh, clean taste drawn from mastic gum and a natural terpene blend (menthone, carvone, cineol).
Berry delivers a fruit-forward profile from real fruit powders — blackberry, raspberry, strawberry, and dragon fruit — alongside natural and organic flavors.
Cinna Mastic is a warm, spiced flavor built on Ceylon cinnamon and a terpene blend of eugenol, cinnamaldehyde, and humulene.
One honest tradeoff of natural flavoring is duration: without synthetic flavor boosters, the taste may fade somewhat sooner than conventional gum.
Some users report that the clean, fresh mouthfeel that remains after chewing — distinct from the lingering artificial sweetness of mainstream gum — is one of the qualities they appreciate most.
Learn more about how natural chewing gum gets its flavor.
Underbrush is positioned as a premium oral care product, and the price reflects two things: a premium ingredient formulation — including hydroxyapatite, botanical resins, and, depending on the flavor, additional minerals and real fruit powders — and a natural, plastic-free chicle base that costs more to produce than conventional gum bases.
It's best understood not as a one-to-one replacement for a pack of drugstore gum, but as a daily oral care addition that fits conveniently into your routine.
Each piece is designed for a long-lasting chew, allowing users who choose to do so to reuse a piece during a chewing session.
As with any wellness product, we encourage you to evaluate it against your individual oral health goals and in consultation with your dental provider.
See how Underbrush compares to other options in our 2026 US guide.
The ingredients used in Underbrush are commonly used in food, oral care, and consumer products, and the formula is sugar-free and free from common allergens.
Individuals who are pregnant, breastfeeding, have underlying health conditions, or have concerns about any ingredient should consult a qualified healthcare professional before use.
For young children, parental supervision is recommended, and we advise following the guidance of a pediatric dentist.
One important note for pet owners: xylitol is safe for humans but is toxic to dogs, so keep this and any xylitol-containing product away from pets.
Learn more about whether nano-hydroxyapatite is safe.
