About Dexcom

By Derek Lakin
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.


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.


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.

Read 47 Dexcom Customer Reviews and Complaints

Write a Review
Average Customer Rating: 1.1
Rating Snapshot:
5 star: 0 4 star: 0 3 star: 1 2 star: 3 1 star:  43
Bottom Line: 0% would recommend it to a friend
Showing 1-11 of 47
Sort reviews by:

  • Dexcom is focused on profits, not patient service

    • By Mark D.,
    • Lawrence, KS,
    • Feb 24, 2020
    • Verified Reviewer

    I love the Dexcom G6 system, which performs wonderfully to provide blood sugar readings over 5-minute intervals to your phone, and the Clarity software is easy to use, provides awesome analysis tools, and even allows me to provide my doctor access to the readings. These are the positives.

    Unfortunately, the negatives are awful. My experience reordering sensors and transmitters has been horrendous. Orders I have placed online offered a variety of shipping options, and I have generally chosen the 3-day option. Most of the orders I have placed in the past year have been delayed and have taken weeks to be delivered. And the problem is Dexcom, not the courier. I have emailed customer service and rarely get a response. The time I did receive a response via the email option, it came almost 36 hours later. By then, I had given up and called the customer service number. By then, the order was 8 days old, and I was down to my last 2 days of sensor life on my remaining supply. The customer service rep (CSR) said the hold-up was insurance verification. I clarified that I was prompted to verify my insurance information in the order process and fully complied, so asked if the issue was on Dexcom's end, verifying whether the info I provided was consistent with the insurance company's records. He said yes. I've dealt with my insurance company on earlier issues with Dexcom, and the insurance company has superior customer service, so I suspect Dexcom was sitting on the order. The rep said he would get the order released for carrier pick-up that afternoon. Two days later, my order was picked up by FedEx, and the tracking information shows the order will arrive FOUR DAYS AFTER IT WAS PICKED UP. That will be 14 DAYS AFTER THE ORDER WAS PLACED.

    Dexcom is very efficient at charging your credit for your orders, at the expense of accuracy. I had experiences last year when Dexcom charged my card so early that the charges appeared on my bill before I received my insurance company's explanation of benefits statement. After discovering, as a result, that I had been billed for charges that my insurance company had covered, I called my insurance company to address the issue, which quickly determined I was overbilled for a total of over $700 for two orders. The insurance company rep followed through by contacting Dexcom, which responded by stating my credit card would be credited for the full amount. I waited for over a month to no avail, had to call my insurance company again. The insurance rep called Dexcom while I waited on hold, and after addressing the matter with his contact, patched me into a 3-way call to get a commitment from the Dexcom rep that the credit would be provided in the next day or two. Monitoring my credit card online, I received the first of two credits in two days, and a second for the remaining balance in four days.

    Dexcom offers an excellent product that overwhelmingly exceeds the quality of the company's patient care and customer service. I believe it is practices like Dexcom's that call for more thorough federal regulation of companies that are granted patents for drugs and medical supplies. If those granted the patents for medical devices cannot provide adequate services to sufficiently respond to patient needs by meeting reasonable standards of service, the patents should be permanently revoked, freeing the formula or technology opened to competitors to produce, sell, and distribute. I could guarantee that that type of check and balance would motivate Dexcom's behavior to better respond to its patients or at least provide them sufficient competition to promote patient welfare that is seriously lacking in this instance.

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

  • Lack of customer service

    • By Gordon L.,
    • San Antonio, TX,
    • Jan 14, 2020
    • Verified Reviewer

    I am a Medicare/Tricare for Life customer of Dexcom. I use the G6 sensors and transmitter. They are wonderful products. Using the call center that Dexcom routes its calls to is absolutely useless. I tried reordering my supplies, I called Dexcom, was routed overseas, the agent said I did not have a valid Medicare number and to call my doctor's office and get one. The next said I needed a four-day investigation to determine benefits although Dexcom used my Medicare account the month before. My sensor expires in 8 days after that I’ll move to another CGM with USA-based customer service.

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

  • In my opinion this is a rip-off company

    • By Patricia C.,
    • Alabama,
    • Jan 8, 2020
    • Verified Reviewer

    I have been dealing with Dexcom for over a year now. I filled out the information required to have a representative contact me about ordering the Dexcom G6. I first waited until Medicare-approved paying their part for this apparatus. When I called I was asked to pay cash then try to get my money back from Medicare. Are you kidding me? I know this wouldn't go too easy if I ever got my money back from Medicare. I told him I couldn't afford this. He then told me to call back in 3 to 4 months and maybe they would have some machines available to Medicare Insurance clients then. I waited again and called back with the same runaround. I think Medicare should check into the practices of this company. Am I not being discriminated against by Dexcom for only having Medicare insurance along with my supplementary insurance instead of having the cash needed to purchase this Dexcom G6.

    Needless to say, I am still sitting here with no Dexcom G6. I am in my 70's and type 1 diabetic but who cares? Certainly not Dexcom. In my opinion, I call this company a rip-off and disgraceful company to do business with. I don't know how they get anyone to work for them and most involved with this company will account for their actions some day. If you can go with another CGM system then I would advise it as that is what I am going to do myself.

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

  • Do not drink the Kool-Aid

    • By David H.,
    • United States,
    • Dec 12, 2019
    • Verified Reviewer

    My frustration with this company and also US MED (once you are assigned a medicare supplier you are stuck) can not be described in language suitable to be printed!

    I am out of supplies and US MED says they don't have any but when I call Dexcom they say they have plenty (G6 system).

    Don't get sucked up and depending on these people as I was.

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

  • OK, BUT...

    • By Heath M.,
    • Victoria, Australia,
    • Nov 13, 2019
    • Verified Reviewer

    Have been a freestyle Libre user for 18 months with a Miao Miao and thought I would try a Dexcom.

    Insertion is OK and it is compact, etc. Software interface is easy enough, however...

    Signal loss issues. I can't tell you how annoying it is to wait up to 30 minutes to reconnect it to my phone if I walk to the other end of the house or just go into the next room without my phone.

    I went for a run this morning and when I got back I did a few things in the next room, you guessed it, signal loss, been waiting 20+ minutes for it to reconnect all the time wondering about my levels after my run. So off to do blood pricks.

    With the Libre and Miao Miao, the range is much much larger and when it drops out it instantly reconnects. I mean how hard can it be?

    In all, it is a NO from me. I will spend my cash on the Libre Miao Miao combo.

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


    • By Patrick K.,
    • Chandler, AZ,
    • Oct 25, 2019
    • Verified Reviewer

    The Dex product is good. However, Dex customer service will be the worst you have ever experienced. If you call CS, you will be on hold for at least 20 minutes EVERY time (with what may be the worst hold music ever - it's all I can do to not hang up!). Worse is trying to reorder supplies. It is next to impossible to get Dex to send supply reorders on time. They let reorders sit, and they don't email or call with updates.

    My advice? Though a great product, avoid Dex because of the horrific customer experience.

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

  • No support from Dexcom

    • By Mike S.,
    • Shawnee, KS,
    • Oct 22, 2019
    • Verified Reviewer

    I’ve contacted Dexcom multiple times and started the process to get set up to get a Dexcom CGM. After weeks of this process, I have not received any follow-up phone calls to get processed and approved for use of a CGM. Dexcom service is awful and it’s ridiculous how difficult it is to get their product.

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

  • Horrible customer service

    • By Niall M.,
    • Charlotte, NC,
    • Oct 15, 2019
    • Verified Reviewer

    Worst customer service imaginable. No follow-up. If you place an order for supplies, be prepared for (i) lengthy delays, often with no order shipped often until your 2nd, 3rd or 4th call; (ii) broken promises regarding shipment dates, and (iii) totally non-responsive customer service. FYI…even the SUPERVISOR’S promise (my FOURTH call) to ship "by tomorrow" was broken. Long-standing backlog on inventory causes lengthy delays between order and shipment, but the company has done nothing to come up with a solution. A billion-dollar company like Dexcom could increase manufacturing if it cared, but it obviously does not. It sells all it can make and has no competition. This is what happens when consumers have no real choice and is a perfect example of the ugly side of patent protection. Unless you have hypoglycemic insensitivity (like most potential Dexcom users) go with Libre instead of Dexcom!

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

  • Bad product/terrible support

    • By Warren F.,
    • Fort Myers, FL,
    • Oct 9, 2019
    • Verified Reviewer

    When the CGM works it’s a great product. When it doesn’t work it’s frustrating and potentially dangerous.

    Way too many communication failures. Sometimes wait 30-45 minutes, sometimes it’s a sensor failure. I had 2 sensor failures yesterday.

    Also, frequent inaccurate readings. Sometimes up to 100 points higher than from an actual finger stick. My CGM showed a reading of over 180 the other night. The actual bg count was 88. If I actually trusted the CG5 I would either be in the hospital or dead. No excuse for this.

    Other than shipping out replacement sensors, customer support is basically useless. Lots of time asking questions but no resolution to problems other than sending additional sensors.

    To make things worse, my transmitter has about 1 more week to go and my distributor told me that they have not received any shipments. So it won’t matter if the senors are inaccurate since the transmitter won’t work.

    There are other CGM systems. I recommend you investigate them before ordering from Dexcom.

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

  • Great product, horrible customer service and support

    • By Diane L.,
    • Manchester, NH,
    • Aug 30, 2019
    • Verified Reviewer

    I actually love my CGM. It has changed my life. However, getting in touch with customer service, ordering supplies or getting your supplies from the company is horrible and disastrous. They do not allow you to order online. You can't reach a live person ever and they always have to call you back. I have not received my order for this month and have been without supplies for almost two weeks. I have been hung up on twice since Monday and they still have not "approved" my order with their internal documentation department even though my insurance company has already approved it. My provider has called and tried to contact the local rep to no avail. If I could use another company I would, but they are the contracted company for my insurance.

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

  • Horrible customer service

    • By Heather O.,
    • Michigan,
    • Aug 29, 2019
    • Verified Reviewer

    Requested a call back after 10 minutes last night, nobody ever called back. Last 2 sensors failed and I have absolutely nothing. Holding now for 30 minutes again while I'm at work. Have had supplies shipped to the wrong address 3 times. They don't care about me what so ever.

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

Showing 1-11 of 47

Write a Review for Dexcom!

Share your experience to help others shop smarter & discover great products.

Write a Review