Proud sponsors of Joel Webbon
The gum in your pocket is plastic and glue.
One ingredient, cut by hand off the bark. A piece holds its chew for hours instead of minutes, and there’s no synthetic base in it to come apart in your mouth while you chew.
Two pocket tins, one of each shape. Chew both, then buy the full-size tin of whichever one you keep reaching for. Code JOEL is already applied.
The Greco Gum Starter Pack
25% off as a bundle, plus another 15% with code JOEL.
4.8 from 1,000+ reviews100,000+ tins sold
15% off everything else too
Code JOEL takes 15% off anything we sell. Full-size tins, capsules, all of it.
You’ve been pulling industrial junk out of your house one product at a time. Gum never makes the list, and it’s one of the worst things in your pantry.
Greco Gum is what people chewed before gum became a factory product. It’s mastic resin, and they were chewing it on Chios two thousand years before anyone thought to replace it with rubber.
One: what you’re chewing now
The base holding your gum together is synthetic rubber. The FDA lets manufacturers build it out of whatever polymers they like and name none of them, because the whole base counts as one ingredient on the label. Here’s what they use.
Polyethylene
the plastic in shopping bags
Styrene-butadiene
the rubber in car tires
Polyvinyl acetate
the glue in Elmer’s
In 2025, researchers at UCLA had people chew gum and measured what came off into their saliva. On average it shed around 100 microplastic particles per gram, and some pieces shed far more. Most of it came loose in the first eight minutes, while the piece was still in their mouths.1
microplastic particles shed from a single piece of gum
UCLA, 2025
We won’t tell you what that does to you, because the research is still running. Here’s what they’ve found so far. Cut open a human artery and the plastic is in the plaque, and the people who had it there were four and a half times more likely to have a heart attack or a stroke in the three years that followed.2 They found it in every testicle they tested.3 They found more of it in human brains than in the liver or the kidneys, and most of all in the brains of people who died with dementia.4
Decide for yourself how much that bothers you. Either way, you’re adding to it every day for a stick of flavored rubber. Mastic has no base to break down, because the resin is the gum.
Two: what you’d chew instead
Under Ottoman rule the crop on Chios belonged to the sultan’s own family, and taking any of it carried the death penalty. People had been chewing it on that island for two thousand years by then. Hippocrates prescribed it for the stomach around 400 BC. It’s still one of the ingredients in the Greek Orthodox recipe for holy chrism, and UNESCO lists the way it’s cultivated as intangible cultural heritage.
What made it worth guarding is that the tree grows in the south of Chios and nowhere else in the world. Cut into the bark and it bleeds a resin that hardens on the branch into tears you can pick off by hand. That resin is the whole product. No base, no sweetener, no flavoring, nothing to add.
It’s still worth guarding. The resin carries EU protected-origin status, the same as Champagne, so nothing from anywhere else can be sold as Chios mastiha.
Three: what it does for you
Your jaw is what you’ll notice first, because you feel it the same day. What keeps most people chewing is everything else.
Settles stomachIt settles a heavy stomach after a big meal. Mastic is registered with the European Medicines Agency as a traditional herbal medicine for mild dyspeptic disorders.5
Clears breathBad breath and the coating on your tongue both come from bacteria in your mouth. Mastic is antibacterial, so it goes after the source instead of covering it up.
Works jawIt’s dense, and one piece holds up for hours, so it works all four of your jaw muscles the whole time. You’ll feel it the next day.
of people with ongoing indigestion improved on mastic, against 40% on a placebo
Double-blind, placebo-controlled trial, 148 people6
What chewers say
“The best all-natural gum I’ve come across. Gut health, stronger jaw, no microplastics. No-brainer.”
“I’ve noticed a change in my gut, which is very positive. And I love the taste.”
“This stuff rules. My mouth feels cleaner, breath fresher. Just good stuff all around.”
“I’ll never go back to regular gum now.”
“I try a lot of supplements and keep the good ones. In a short time, I can tell this is one I’ll keep.”
“It doesn’t lose its consistency, texture, or taste, even chewed for hours.”
“Enjoyed the gut health benefits, and a great jaw workout too.”
“Chew it for hours until your masseters are sore. Leaves your teeth feeling like you just left the hygienist.”
“Great gum. Feel healthier already.”
“Taste is mild and natural, and it lasts a long time.”
“It doesn’t stick to my teeth and the flavor is neutral. Really enjoy it.”
“Love all the health benefits tied to this gum.”
“Very high quality. I can feel a difference in my mouth and jaw already.”
“Easy to chew, and it leaves my mouth feeling clean and refreshed.”
“Fantastic quality, and exceptional customer service.”
“I love having a healthy way to chew every day.”
“Great texture and good quality.”
“Been using it daily for two weeks. Will reorder.”
“Great jaw workout. Teeth feel cleaner, mouth feels fresh. Will be buying again.”
“I consider this heavyweight chewing gum. I like it.”
“Great exercise for your jaw without the microplastics.”
“I no longer chew regular gum. The nuggets are great for oral health.”
“Great packaging, and exactly what I wanted for my jaw.”
“Lasts a very long time, and you can feel the workout it gives your jaw.”
“Love the smaller droplets.”
“First time using the nuggets and they’re amazing.”
“Love the nuggets. Buy them if they’re available, because they go fast.”
“Easier to chew than the droplets, and both have their uses.”
“Great flavor and texture.”
“Works good. Jaw stronger. Teeth cleaner.”
Real Chios mastic
It comes down to where it grows and how it’s made.
One island
It refuses to make its resin anywhere but the southern half of Chios, across two dozen villages, the mastichochoria.
Rare chemistry
The antibacterial and anti-inflammatory compounds that do the work only form in real mastic. Cheaper resins from other trees can look the part and do nothing.
Cut by hand
Growers score every tree by hand each summer and wait for the resin to weep and harden into tears. A full year of one tree fills barely a single tin.
We buy ours straight from the growers’ association on Chios, so what ends up in your tin is the real thing and nothing else.
Before you buy
Make the switch
There’s no habit to build here and nothing to remember. Right now what you’re chewing is plastic, and you swallow what comes off it. One tin of this replaces weeks of that.
The Starter Pack
4.8· 1,000+ reviews
25% off as a bundle, plus another 15% with code JOEL.
Secure checkout. Covered by our 30-day guarantee.
From our customers.
Our 30-day Spit-It-Out Guarantee
Chew it for a month. If mastic is not for you, email us and we refund every cent, shipping included. Keep the tin, there is nothing to send back. We would rather eat the cost than argue with you about gum.
P.S. The harvest on Chios is small and we run dry more than once a year. If both tins are in stock as you read this, that’s your window. Code JOEL takes 15% off whatever you order, and it holds for as long as the sponsorship runs.
Shop the rest of the range
About this page. This is an advertisement for Greco Gum, run in connection with a paid sponsorship of Joel Webbon and NXR Studios. Greco mastic gum is a food product, not a medical treatment, and nothing here is intended to diagnose, treat, cure, or prevent any disease. Microplastics research is ongoing; the findings described above are those of the cited studies, and we make no claim that any specific health outcome follows from chewing ordinary gum. Raw mastic gum is naturally hard and may damage dental work like fillings, crowns, or braces; by purchasing you accept responsibility for any resulting dental issues.
Mohanty, Sanjay, Lisa Lowe, and Jamie Leonard. “Ingestion of Microplastics during Chewing Gum Consumption.” Journal of Hazardous Materials Letters (2025). sciencedirect.com. ↩
Marfella, Raffaele, et al. “Microplastics and Nanoplastics in Atheromas and Cardiovascular Events.” New England Journal of Medicine 390, no. 10 (2024): 900–910. doi.org. ↩
Hu, Chelin Jamie, et al. “Microplastic Presence in Dog and Human Testis and Its Potential Association with Sperm Count and Weights of Testis and Epididymis.” Toxicological Sciences 200, no. 2 (2024): 235–240. doi.org. ↩
Nihart, Alexander J., et al. “Bioaccumulation of Microplastics in Decedent Human Brains.” Nature Medicine 31 (2025): 1114–1119. doi.org. ↩
European Medicines Agency, Committee on Herbal Medicinal Products. “European Union Herbal Monograph on Pistacia lentiscus L., Resin (Mastix).” EMA/HMPC/46756/2015. ema.europa.eu. ↩
Dabos, K. J., E. Sfika, L. J. Vlatta, et al. “Is Chios Mastic Gum Effective in the Treatment of Functional Dyspepsia? A Prospective Randomised Double-Blind Placebo Controlled Trial.” Journal of Ethnopharmacology 127, no. 2 (2010): 205–209. doi.org. ↩
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