Feno rethinks the toothbrush entirely: a custom-fitted U-shaped mouthpiece with about 18,000 bristles cleans all your teeth at once in a 20-second cycle, while built-in cameras feed an app that tracks your oral health. It is clever and genuinely different, but it costs about $299 to start, takes some getting used to, and the app's insights are coaching rather than a substitute for your dentist.
What we like
- Cleans the whole mouth at once in a 20-second cycle, with a longer mode available
- Mouthpiece is sized from an in-app bite scan, with free size exchanges
- Built-in cameras and app give scans, trends and personalized coaching
- Week-long battery with wireless and USB-C charging
- HSA and FSA eligible, with a 30-day money-back guarantee
Keep in mind
- Expensive compared with a quality conventional electric toothbrush
- Adjustment period; some users notice strong vibration or initial gum bleeding
- Best features depend on the app and an optional membership
- Early reviews are mixed, from enthusiastic to strongly negative
The toothbrush has barely changed in decades: a small head of bristles that you move tooth by tooth for two minutes. Feno Labs set out to replace that routine. Its Smartbrush uses a U-shaped, custom-sized mouthpiece packed with about 18,000 bristles that surround every tooth at once, so a full clean takes around 20 seconds. A handle with built-in cameras and sensors then feeds data to an app that tracks your gums, plaque and habits over time.
That is a big promise, and it comes with a premium price. In our research we looked at how the Smartbrush works, what is included in each bundle, what reviewers have liked and disliked, and who is most likely to get value from a toothbrush that also wants to be an oral health monitor.
What Feno is trying to do
Feno Labs, Inc. positions the Smartbrush as an oral health system rather than a gadget. The idea is that two problems hold most people back: they do not brush long enough, and they rarely know how well they are doing between dental visits. By cleaning every surface in one short cycle and scanning the mouth regularly, Feno aims to solve both at once.
The company says more than 20,000 people have rated it highly. Independent ratings are more measured, with an average of about 4.4 out of 5 on Trustpilot from a relatively small number of reviews at the time of our research, and some tech reviewers have been openly critical of the experience.
It helps to see Feno as two products in one. The first is a brushing tool that changes technique, replacing careful tooth-by-tooth movement with a mouthpiece that does the coverage for you. The second is a monitoring service that tries to make oral health visible between checkups. You can value one without the other, and that distinction shapes whether the price makes sense for you.
How the Smartbrush works
- TrueFit Mouthpiece: a U-shaped brush that covers upper and lower teeth at once. During setup you take a roughly 90-second bite scan in the app, and Feno selects from seven sizes. Replace the mouthpiece about every three months.
- Bristles: about 18,000 soft nylon bristles, compared with roughly 2,500 on a typical brush head.
- Brushing time: a 20-second full-mouth cycle, with a 30-second option that some users prefer.
- Smarthandle: houses the motor plus cameras and sensors that scan teeth, gums and tongue and track motion and pressure.
- App: records sessions, shows trends, produces Oral Health Reports and a Feno Score, and offers an AI coach.
- Battery: about seven days per charge, using the included wireless charger or USB-C.
Feno recommends its own Feno Foam toothpaste, made with xylitol and wild mint, but says regular toothpaste also works.
See Feno's current range
Bundles and pricing
Feno sells the Smartbrush in bundles rather than on its own. Prices we saw during our research:
- Founder's Edition Bundle (about $299, with promotions from $199): Smartbrush handle, one TrueFit mouthpiece, three tubes of Feno Foam (roughly a three-month supply), wireless charger and a tongue scraper.
- Founder's Edition Plus (about $399): adds 12 months of Feno Plus.
- Elite Oral Health Bundle (about $519): adds a salivary microbiome test.
Feno Plus is an optional membership that adds AI scans, review by an oral health coach and an extended two-year hardware warranty with no-questions-asked replacement. A subscription for refills saves money over time, and the Smartbrush is HSA and FSA eligible, with Affirm financing available.
What reviewers say
Reaction to the Smartbrush is unusually split. Supportive reviewers like the speed, the sense of a thorough all-over clean and the motivation that comes from seeing scores improve. Several note that it takes a few days to get comfortable with the mouthpiece and vibrations, and that a smaller mouthpiece size can feel better against the back of the gums.
Critics focus on comfort, the novelty of something filling the whole mouth, and the price compared with excellent conventional electric brushes. Some users report gum bleeding in the first days, which can happen with any new brushing routine but should settle; if it does not, stop and see a dentist.
Shipping, warranty and returns
Shipping is free, and orders currently ship from the US, so buyers abroad should expect one to three weeks for delivery. Feno offers a 30-day money-back guarantee from the date of delivery. US orders include a prepaid return label; international customers pay return shipping. The first two mouthpiece size exchanges are free, which is useful given how much fit affects comfort.
Standard hardware coverage is set out on Feno's warranty page, and Feno Plus extends coverage to two years with Smartbrush replacement.
Who it is for, and who should pass
Feno makes the most sense for people who rush or skip brushing, enjoy tracking health data, and like being early adopters. Frequent travelers may also appreciate the week-long battery.
It is a harder sell for anyone on a budget, people who dislike app-dependent products, and anyone with a sensitive gag reflex. People with braces, implants, bridges or ongoing gum treatment should ask their dentist whether a full-mouth design suits their dental work before buying.
Use the 30-day guarantee as a real trial: brush with it twice a day, try both cycle lengths and the alternative mouthpiece size, and decide before the window closes.
Our verdict
Feno is the most ambitious toothbrush we have looked at, and for the right person it can turn brushing from a chore into a quick, measurable habit. It is also expensive, takes adjustment, and has a mixed reception. If you are curious and value data, the 30-day guarantee makes it a reasonable experiment. If you just want reliably clean teeth, a good oscillating or sonic brush and a two-minute timer remain the safer, cheaper choice.
Feno products at a glance
| Product | What it is | Price |
|---|---|---|
| Founder's Edition Bundle | Smartbrush handle, TrueFit mouthpiece, three tubes of Feno Foam, wireless charger and tongue scraper. | about $299 (promotions from $199) |
| Founder's Edition Plus | The core bundle plus 12 months of Feno Plus coaching and extended warranty. | about $399 |
| Elite Oral Health Bundle | Adds a salivary microbiome insight test to the Plus bundle. | about $519 |
| TrueFit Mouthpiece | Replacement U-shaped brush head sized from your in-app bite scan, replaced about every three months. | — |
| Feno Foam | Xylitol and wild mint toothpaste foam, roughly a one-month supply per tube. | — |
Prices as listed on the brand's site at the time of our research and may change. Check the store for current pricing.
Feno FAQs
Is Feno legit?
Yes. Feno Labs, Inc. sells the Smartbrush direct and offers a 30-day money-back guarantee. Reviews are mixed, so treat the guarantee period as a genuine trial.
Does a 20-second brush really clean as well as two minutes?
Feno says its full-mouth mouthpiece cleans every tooth at once, so a 20-second cycle covers what a regular brush does tooth by tooth. Independent evidence is limited, and a 30-second mode is available if you prefer a longer clean.
Do I need Feno Plus?
No. The Smartbrush works without it. Feno Plus adds AI scans, coach review and a two-year hardware warranty, and some bundles include 12 months.
Can I use my own toothpaste with Feno?
Feno recommends its Feno Foam but says regular toothpaste also works with the Smartbrush.
Is Feno HSA or FSA eligible?
Yes. Feno says the Smartbrush is HSA and FSA eligible, and Affirm financing is available at checkout.
Tech-minded adults who want faster brushing and app-based feedback on their habits
Disclosure: InhouseHeal may earn a commission if you buy through links on this page. Our score is based on research of the brand's products, evidence, pricing and policies. How we review.
