About Dexcom

By Derek Lakin
HighYa Staff Published on: Mar 23, 2018

By combining a small, under-the-skin sensor with a receiver or other smart device, Dexcom’s patented, FDA approved continuous glucose monitoring (CGM) system promises to help you easily make diabetes treatment decisions, while avoiding rollercoaster highs and lows.

Specifically, the website explains that you’ll be able to monitor which direction your glucose levels are headed and how fast they’re getting there, for up to 10 hours, without having to stop and prick your finger. In fact, it’s advertised as the first FDA approved device to “let you treat your diabetes without a confirmatory finger prick.”

Together with the fact that Dexcom is approved for use in children as young as two years of age, can help aid in the detection of hyperglycemia and hypoglycemia episodes, and can share your information with loved ones to help successfully manage your diabetes, the company tells us theirs is the best selling, most preferred CGM on the market.

There’s no doubt that diabetes management is all about tracking numbers, but can the data provided by Dexcom’s CGM deliver a more complete picture than the competition? That’s the central question we’ll help you answer here.

The Basics of Diabetes

The Centers for Disease Control and Prevention explains that our body breaks down most of the food we eat into glucose, a type of sugar, which is used to deliver the energy it needs. However, cells only allow glucose to pass through their walls—and therefore process it into energy—after the hormone insulin has attached to the appropriate receptors.

If there isn’t enough of this hormone present, or if the hormone doesn’t function properly, it can cause glucose to build up in the blood (known as blood sugar), leading to potential side effects like “heart disease, blindness, kidney failure, and lower-extremity amputations.”

Not all diabetes is the same, though. Type 1 diabetes requires the use of supplemental insulin, and is often the result of a combination of “autoimmune, genetic, and environmental factors.”

On the other hand, type 2 diabetes, which accounts for 90 to 95 percent of all cases, is not necessarily insulin dependent and can often be mitigated—or even reversed—through a combination of healthy food and exercise choices.

Although diabetes often doesn’t exhibit symptoms until an individual falls ill or experiences side effects, blood glucose tests can help your doctor diagnose the condition in advance. More recently, and as mentioned on the Dexcom website, A1C tests that measure hemoglobin levels can also be used, which report your glucose levels over the course of three months.

What’s the Difference Between Continuous Glucose Monitoring (CGM) Systems & Blood Glucose Meters (BGM)?

For most individuals with insulin-dependent diabetes, accurately monitoring their blood glucose levels involves pricking their finger, placing a drop of blood on a testing strip, and having their readings taken by a blood glucose meter anywhere between two and 10 times per day, depending on their doctor’s treatment plan.

Contrastly, the National Institutes of Health explains that a CGM “works through a tiny sensor inserted under your skin, usually on your belly or arm. The sensor measures your interstitial glucose level, which is the glucose found in the fluid between the cells. The sensor tests glucose every few minutes. A transmitter wirelessly sends the information to a monitor.”

This way, instead of waiting an hour or more between each blood glucose test, which will only provide a snapshot of your levels at any one time, CGMs like Dexcom can provide readings every five minutes, up to 288 times over a 24-hour period.

Together, CGMs have been shown to help provide active monitoring at night, reduce hypoglycemia, and decrease A1C an average of 1.3 percent in type 1 diabetics. How, exactly, does the Dexcom system accomplish this?

Taking a Closer Look at Dexcom’s Products

While you can reach out to the company for additional information and see if you qualify for their G5 system, it requires a prescription, so it might be ideal to speak with your doctor in advance.

Dexcom G5 Mobile System & App

Dexcom’s G5 CGM consists of three main parts:

  • Sensor – A tiny, flexible device that’s inserted under the skin using a special needle that measures glucose levels and remains in place using tape-like adhesive for up to seven days.
  • Transmitter – This wirelessly sends readings taken by the sensor via Bluetooth to your receiver, or iOS or Android smart device.
  • Display device – Allows you to view and track your glucose level trends in real time and vivid color.

Once set up, the under-skin monitor will take glucose readings five minutes apart and send them to the device, so you can see how your levels are trending over time. Important: While this system might help users go as long as 10 hours without having to prick their finger, the website’s FAQ emphasizes that you’ll still need to calibrate with a finger stick twice per day.

Whether using a supported iOS or Android device or Dexcom’s touchscreen receiver, users will see their current glucose readings and an associated color:

  • Red means you’re below your set target rate.
  • Yellow means you’re above your set target rate.
  • Gray means you’re within your target range.

Arrows will also display the speed and direction your glucose is heading: Two down arrows mean you’re dropping fast, while one arrow down means you’re dropping more slowly.

Dexcom App ScreenshotsAfter sending data from the sensor, Dexcom’s G5 app can track information and provide useful graphs, reports, and other insights, along with customizable alerts. Credit: Google

You can also set customizable high and low glucose level thresholds, which will alert you when you're at or below a lower threshold, when you're trending up or down, or when you're out of range. These can work as audio and vibrate alerts, or as text messages.

If you prefer, Dexcom’s built-in Share feature helps up to five other individuals co-manage your diabetes by receiving these same alerts, who can also see your glucose levels in real time on their compatible smart device.

Together, the company advertises that you’ll be able to view trends over time, whether online or via the app, detect patterns (e.g., spiking or dropping during the night), and make better diabetes treatment decisions.

Dexcom STUDIO

For Windows users, this CGM software downloads data from the G5 system in seconds, and uses a streamlined interface to create printable reports and charts for additional insights:

  • PORTRAIT Report – Prioritizes and identifies “clinically significant glucose patterns” and provides “possible solutions to improve glucose management.”

  • Pattern Map – Tracks the frequency, duration, and intensity of glycemic excursions.

  • Insights and Potential Solutions – Highlights significant hyper- and hypoglycemia patterns and provides “possible clinical considerations.”

  • Summary Statistics and Interpretation – Glucose statistics, calibration frequency, and “a place for written therapy adjustments and suggestions to help improve glucose control.”

  • Hourly Stats, Daily Stats, & Daily Trends Reports – Glycemic patterns and variability, as well as the percent time spent high, low, and within target glucose ranges.

  • Glucose Distribution & Trend Reports – Helps assess pre- and post-prandial control by displaying overall glucose distribution, "event markers and the correlation between SMBG and CGM."

  • Success Report – Allows you to compare glycemic control on a weekly, monthly, or quarterly basis.

Dexcom Pattern MapDexcom’s Pattern Map shown above, which is part of the company’s STUDIO reporting system, allows users to track their glycemic excursions. Credit: Dexcom, Inc.

Dexcom CLARITY

The cloud-based version of STUDIO, which provides the same ability to “access and track your glucose data anywhere, on any web-based platform,” but that’s targeted toward Mac users.

Dexcom Follow App

While Dexcom’s G5 sensor will send the information it gathers directly to your device, their Follow app allows up to five other people to remotely monitor your glucose data and trends.

Could Dexcom’s G5 System Cause Side Effects?

Although Dexcom’s G5 is the “the first FDA-approved continuous glucose monitoring system that can be used to make diabetes treatment decisions without confirmation with a traditional fingerstick test,” it’s not for everyone.

For example, it can’t be used by children under the age of two, pregnant women, or by those on dialysis. The sensor also must be removed before undergoing an MRI or CT scan, and can only remain submerged in water for less than 30 minutes (in case you plan on going swimming or taking a long bath).

Finally, users are instructed to never use the same insertion site twice in a row, which could result in irritation.

You’ll need to get a prescription from your doctor in order to purchase Dexcom, at which point you should discuss these and other potential side effects based on your specific diagnosis.

How Much Does Dexcom Cost?

Since Dexcom’s G5 is a prescription-only system, a pre-approved account is required in order to access their store and related product prices. To request one, you can fill out a form on the company’s website, which involves entering personal information and brief details about your diabetes therapy.

No prices are listed on the Dexcom website, although their FAQ indicates the system might be eligible for coverage for qualifying patients (typically, those with type 1 diabetes, or those with type 2 diabetes and who take insulin with every meal) under some Medicare plans.

There also weren’t any refund details were provided, although each mobile transmitter is covered under a three-month limited warranty (beginning from its first date of use) against defects in material and workmanship under normal use.

If you need to process a warranty claim or even need help setting up your device, the 24/7 support and diabetes coaching team can be reached at customerservice@dexcom.com. Their website also offers several guides and tutorials.

What Can We Learn From Dexcom Customer Reviews?

Between iTunes and Google Play, we encountered nearly 900 combined customer reviews at the time of our research, who had given the Dexcom app an average rating of about three stars.

Although only a handful provided direct feedback, common compliments cited insightful information, while complaints often regarded bugginess, as well as missing important details (e.g., no values for carb and insulin entries, the ability to add unlimited custom schedules, readings only go up to 400, etc.). A company representative responded in each instance.

We found a handful of hands-on Dexcom system reviews on other sites, although the majority referenced the previous G4 Platinum version. However, TheDiabetesCouncil.com’s Bridget Montgomery provided some in-depth insight earlier this year, stating that it was simple to use and easy to calibrate, although they noticed the app depleted battery life faster, along with limited Bluetooth transmitter range (five to 10 feet).

From a company perspective, Dexcom, Inc. was founded in 1999 and is based out of San Diego, CA. They held a D- rating with the Better Business Bureau, based on 12 customer reviews and 25 closed complaints, as of 3/19/18. Most referenced support issues, and the company hadn’t responded to 10 of these complaints at the time of our research.

Dexcom vs. Freestyle Libre, Medtronic Guardian Connect, & Other Continuous Glucose Monitoring Systems

While we didn’t encounter a ton of competition for Dexcom, we did come across two other prescription-based CGM systems during our research that also implement thin, flexible filament sensors inserted underneath the skin, allows users to avoid sticking their fingers (except for calibration), provides continuous monitoring, and are often covered by some private insurance and Medicare plans:

Product Price Special Features
Dexcom $480 per transmitter; $80 per sensor iOS and Android app connectivity, data transmitted via Bluetooth, transmitter requires replacement every 7 weeks, Windows and Mac-based reporting programs, Follow app (share functionality)
Freestyle Libre by Abbott Laboratories $69.99 for reader; $25.99 per sensor (or, about $80/mo) Sensor (good for 10 days) attaches on the upper arm, sends glucose data once per minute, requires separate display (no smartphone support) that must be scanned on the sensor, only available for those 18+
Medtronic Guardian Connect $699 transmitter; up to $75 per sensor Not available until summer 2018, abdomen-based sensor must be replaced every few days, app connectivity, predictive alerts, diabetes management software, caregiver data share, only available for those 18+

How to choose the right one for you? Like many other consumer products (health-related or otherwise), it’s largely going to come down to your needs and preferences.

For example, at $69.99 for the reader and $25.99 for each sensor, the Freestyle Libre is the lowest priced CGM above. Functionally, however, it’s perhaps the most limited (we didn’t test any of these devices firsthand to provide direct feedback), since there’s no app connectivity and you must manually scan the arm-based sensor in order to download data. With the reader, you’ll also have one more electronic device to keep track of.

On the other hand, if you want an app-based CGM and want it now, the Dexcom G5 is the only game in town, since the Medtronic Guardian won’t be available until summer 2018. You’ll have to pay a not-insignificant amount for the sensor, though, and each one is more than three times the cost of the Libre version. They only last seven (versus 10) days, to boot.

But as mentioned on Dexcom’s website, their system is currently your only option if you’re under the age of 18, or if your smart device works on an Android platform.

Speaking of the Guardian, it’s perhaps the closest in functionality to Dexcom’s G5, as well as sensors that are very close in price. However, the first transmitter will cost you $700, which is significantly higher than the competition.

What does all of this mean for you?

Our Final Thoughts About the Dexcom CGM

Compared to traditional blood glucose meters, continuous monitors offer several potential advantages, including less finger-pricking, more frequent measurements, and detailed software that can identify and predict trends, all helping you to better control your diabetes.

But, when trying to figure out which option will deliver the most value for the money, can you expect the Dexcom G5 system to deliver a more complete picture than the competition, as claimed on the website?

Again, we didn’t test any of these devices ourselves, but if you’re looking for app connectivity, detailed reporting, and sharing ability, it’s currently the only option until the Medtronic Guardian releases later this summer—which will also be priced meaningfully higher at $799 for its receiver.

Together, as reported in The Diabetes Council article cited earlier, if you’d prefer not to carry an additional receiver, are a parent or caregiver of someone with diabetes, would like the most insight into your diabetes management, or are a heavy sleeper who has trouble waking up to alarms, it might be difficult to go wrong with Dexcom—especially if you're covered by private insurance or Medicare.

Just remember that it’s not a one-time purchase since you’ll have to pay about $75 per month for replacement sensors.

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18 Consumer Reviews for Dexcom

Average Consumer Rating: 1.1
Rating Snapshot:
5 star: 0 4 star: 0 3 star: 0 2 star: 1 1 star:  17
Bottom Line: 0% would recommend it to a friend
Showing 1-11 of 18
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  • The most horrendous customer service in the world

    • Denver, CO,
    • Feb 12, 2019
    • Verified Reviewer

    First, the product is great, it has given me a peace of mind like no other diabetic device.

    In one of the reorder evolutions, Dexcom insisted that my doctor write another script even though the current prescription was still valid. My doctor refused and the battle was on, for months. Eventually, I had to pull the patient welfare card, and pleaded with my doctor to write another script and insisted that I was the one suffering from his refusal to write on a piece of paper. He insisted that I filed a complaint with the state. I fired him and sought the help of another Endo.

    Come to find out my doctor wasn’t the problem, it was Dexcom. Every reorder. and God forbid a new script, insurance reauthorization, there is a major issue. On average I spend three hours talking to Dexcom’s reps for each order. I should be paid by Dexcom as much as I’ve been on the phone with them. I can recite their hold music, "Opus No. 1" by Tim Carlton & Derrick Deel in my sleep (it sounds like it belongs in a bad 90’s movie).

    In defense of the Dexcom reps, they have been nice but lack the ability to do anything correctly. I’ve had them mistake a third party biller for my insurance, try coding me on Medicare, and one time they were going to ship the devices to my insurance company. It’s a shame, not sure how long they can go on like this.

    Bottom Line: No, I would not recommend this to a friend

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  • 1 out 1 people found this review helpful

    Worst customer service EVER!

    • Jan 25, 2019
    • Verified Reviewer

    The receiver can be up to 120 points off. Customer service is the pits. You can wait for over 2 hours to order supplies...and then the order doesn't show up. Just try getting through to complain.

    Bottom Line: No, I would not recommend this to a friend

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  • 2 out 2 people found this review helpful

    Rotten support

    • Seattle, WA,
    • Jan 20, 2019
    • Verified Reviewer

    My grandson is diabetic and is a Dexcom device. I downloaded an apparently upgraded app to my Android smartphone successfully but got a mysterious message about not following anyone. When I tried to get help from support I was put on hold (no exaggeration) 18 minutes and then I got a recorded message asking me to participate in a survey. I called another tech support number. This one was busy. I tried again and again. I tried calling marketing, left an email requesting the information. Nothing. I then emailed tech support requesting the information. No response.

    This is an important health device. When it malfunctions or simply doesn't function, is it really too much to respond to customer questions about how to make it work? Really crappy service.

    Bottom Line: No, I would not recommend this to a friend

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  • 3 out 3 people found this review helpful

    Nice but No Support. They don't answer email or calls

    • Moore, Oklahoma,
    • Nov 24, 2018
    • Verified Reviewer

    I received a CGM from them G5 and it was great, after 2 months the company that supplied me the sensors stopped communicating with me, I can't order any more sensors. I call and get disconnected, their web login doesnt work, I call, they don't return phone calls.

    I write Dexcom about the problem and they don't answer email either. I am stuck with something I cant use.

    Bottom Line: No, I would not recommend this to a friend

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  • 3 out 4 people found this review helpful

    Terrible customer service

    • Tennessee,
    • Nov 14, 2018
    • Verified Reviewer

    I have had nothing but terrible customer service with Dexcom, the past two times we have needed sensors, they tell me we will get those sent out and after a couple of days of not receiving an email that the order was placed or shipped, I call and they tell me oh, the sensors are on back order. It is a constant problem with them and something needs to be done as the person that needs the sensors now has to go without their Dexcom because they can't seem to keep up with the demand. THIS IS UNACCEPTABLE.

    Bottom Line: No, I would not recommend this to a friend

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  • 4 out 4 people found this review helpful

    Good product, extremely bad service

    • Monroe, WA,
    • Nov 8, 2018
    • Verified Reviewer

    The Dexcom G6 is a really good product. It is, to a great extent, accurate and convenient to have readings every 5 minutes without any calibration. However, their customer service is extremely bad, the worst I have ever experienced.

    First of all, you have to wait way too long to get to speak to a representative. They messed up my billing and it took them 9 months to refund me, 9 months of struggle to get a correct or accurate answer as to what was going on! They are not consistent in what they say. They messed up my order and kept giving me inaccurate information while switching from G5 to G6. One person would say I am not eligible for the upgrade and the other would say it is shipping. Then when I needed a refill, one person said they are one week late in shipping, next week I was told it will ship no later than November 6, he kept repeating "at the latest," and now they say they have 10 business days delay in shipping.

    This is the WORST. I will be moving to another CGM for better service.

    Bottom Line: No, I would not recommend this to a friend

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  • 2 out 2 people found this review helpful

    Cannot return unopened sensors!

    • Carmel, CA,
    • Oct 13, 2018
    • Verified Reviewer

    My girlfriend Lyndsay and I are no longer together. I set-up a delivery for sensors for the G5, so having completely forgotten they would send them, they arrived this week.

    I called Customer Support (very unsupportive in my view), who stated that sensors cannot be returned, even unopened! Apparently this is part of their initial contract when you set-up deliveries, and yet the Packing List states that "no partial or opened products can be accepted for return" - so why do they state this on a shipment of sensors if sensors cannot be returned?

    Appalling, and I would NEVER recommend this company to anybody.

    Bottom Line: No, I would not recommend this to a friend

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  • 3 out 3 people found this review helpful

    Billing department nightmare

    • Plainfield, IL,
    • Oct 2, 2018
    • Verified Reviewer

    Dexcom has always been great. Until they just charge your card out of nowhere, never even send you an invoice after, and just pick what dollar amount to charge you regardless of what your insurance says to pay. Then when you call, they just say too bad. I am completely flabbergasted. I have never had worse service from a company. I definitely see how they make their money and it is definitely at the customer's expense.

    Bottom Line: No, I would not recommend this to a friend

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  • 3 out 3 people found this review helpful

    Dexcom used to be good...

    • San Antonio, TX,
    • Sep 24, 2018
    • Verified Reviewer

    I have been using Dexcom CGM meters since 2005, which started with the 7plus. The current systems that they have now are not as dependable. The G4 was the last CGM that was worth getting. The G5 had issues with the transmitter, which warranty handled. But all the previous models were solid with no sensor errors. Each time I call I am told different information, and they have to put me on hold because they have to double check. They then come back and tell me I am correct. I am not calling to hear their guesses on my question, I am calling to hear facts. Their bland little recital of responses make you feel not valued. Communication is horrible...

    Bottom Line: No, I would not recommend this to a friend

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  • 7 out 7 people found this review helpful

    Hard time

    • Florida,
    • Sep 21, 2018
    • Verified Reviewer

    I had the G5, and being a type 1 diabetic for 41 years, I can tell you it's hardly ever accurate. They just stopped sending me my strips and sensors. No one called. I called three times, and every time I was told it would be delivered. I waited with no delivery. I called again and they told me to just call Medicare over some order of insurance. Whatever. I did and got it all sorted out. They promised I would get a call once I did. No call.

    Then I just spoke to them again and I'm told something else is wrong. This has happened every time I tried the Dexcom, starting with G4 then 5. They have been irresponsible and have ruined how I get strips and no sensors now. I'm left with nothing. Absolutely horrible customer service. Beware, they might just stop sending yours, and you'll have no idea. Ridiculous.

    Bottom Line: No, I would not recommend this to a friend

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  • 5 out 5 people found this review helpful

    Piece of crap

    • Seattle, WA,
    • Sep 8, 2018
    • Verified Reviewer

    This product is one of the biggest piece of crap in medical history. Its readings are always way off by 150 unite or more, causing the patient to take the wrong dose of insulin. If you call and ask for help, it is always the patient's fault it is not working. I've been using it for a few years. It used to be great. Now it’s just a joke.

    Bottom Line: No, I would not recommend this to a friend

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