How hard can it be to build a CGM?!
- Renato Circi & Rafaël Michali
- 6 days ago
- 4 min read
At first glance, it doesn’t add up.
Continuous Glucose Monitors (CGMs) tackle an urgent, global crisis. With over 800 million people living with diabetes, and countless others managing metabolic conditions, demand couldn’t be higher.
Yet somehow, only two companies dominate the CGM market.
Why?
It’s not the size of the market. It’s not the absence of need. And it’s definitely not for lack of trying from the healthcare tech community.
The truth is simpler: building a CGM is mind-blowingly hard. And we should know, we’re doing it. A CGM might look like a small, simple device, but don’t let it fool you. Behind that tiny form factor lies immense complexity.
How can something so tiny be so difficult to build?
Building a CGM is a House of Cards
CGMs aren’t just wearables, they’re invasive devices that interact with the human body 24/7. They require mastery across every engineering discipline - mechanical, electrical, software, biochemistry, materials science - and that’s just scratching the surface. Miss a piece, and the whole system collapses.
But the real challenge isn’t just technical, it’s organisational. Success depends on building a team that can work across disciplines, not in silos, not in sequence - but in parallel.
It’s not only about having the smartest specialist for each discipline - it’s also about building a team that can think holistically and move in sync. Every decision is connected, nothing exists in isolation, and every improvement can introduce a new risk. Mechanical needs to talk to software. Biochemistry needs to talk to manufacturing. And all of it needs to be integrated from day one.
The Body is a Hostile Host
If that wasn’t hard enough, we’re building all of this in the most unforgiving environment imaginable - the human body.
The human body is miraculous, but when it comes to hosting foreign objects, it’s incredibly unwelcoming. Insert a sensor, and the immune system doesn’t hesitate to isolate, degrade or destroy whatever doesn’t belong.
That’s why CGMs walk a razor’s edge. You need materials that are immune to, well, the immune system. But every fix comes with a trade-off - the very materials that the body is more likely to accept can also hinder the performance of the sensor. It’s a game of precision: CGMs have to live in the narrow space between biology’s tolerance and chemistry’s function.
A relentless tug-of-war between acceptance and performance.
Perfection Isn’t a Goal, It’s a Requirement…
And let’s not forget: CGMs aren’t gadgets - they’re medical devices, and that distinction creates a mountain of challenges. Regulatory bodies like the FDA expect perfection. Not “good enough,” not “innovative for its time.” Perfect. Every time. Across millions of units.
You need scalable manufacturing from day one, preemptively solving problems that might arise years down the line. You also need to navigate a regulatory maze: clinical trials, biocompatibility testing, data security, user studies, and a dozen other moving pieces all stack up. The difficulty isn’t in one piece of the puzzle, it’s in the overwhelming number of requirements that have to align flawlessly, all at once.
… And Making Mistakes Comes at a Price
The capital needed to bring a medical device to market is staggering, and so is the cost of getting it wrong.
Choose the wrong equipment? That’s months of lead time and capital down the drain. Pick the wrong adhesive? You’re looking at expensive redesigns, new testing cycles, and production delays. Bet on the wrong sensor material? It might pass lab testing but fail during clinical trials, draining your clinical budget. A single wrong call doesn’t just burn cash - it can sink the entire company.
This reveals a harsh truth about medical device innovation: it’s not enough to have a great idea. You need the stamina, resources, and expertise to navigate a system designed to avoid risk at all costs, while taking massive bets at every turn.
User Experience Can Make or Break You
And even if you clear every technical, regulatory, and financial hurdle, you’re still not done. Because even the best device fails if people don’t want to wear it.
It’s not enough to ask, “Does it work?” The real question is: “Will people want to use it?”
Users don’t care about your engineering masterpiece. You can build the most advanced CGM in the world, only to have users hate wearing it because it pinches, itches, or falls off. That’s why UX isn’t just a feature - it’s the feature.
Fail here, and no amount of capital, MBAs or corporate playbooks will save you.
So, Why the Hell Are We Doing This?
With all these challenges, you’re probably wondering why we even bother.
The answer is simple: because the stakes couldn’t be higher, and the impact couldn’t be greater.
Building a CGM isn’t just another startup challenge - it’s one of the toughest engineering and medical frontiers of our time. And we’ve chosen to take the hardest road: making it as minimally intrusive as possible. Our microsensors sit just beneath the surface, cause less discomfort, and open the door to a radically better experience for the people who rely on this device every day.
That choice raises the bar everywhere - sensing, stability, biocompatibility, manufacturing. It forces every part of the system to operate at its edge. But it also means delivering something people genuinely want to wear, not just tolerate.
Harder, yes. But also transformative.
You might think we’re crazy for even trying. But you know what’s even crazier?
We know we can do it.