If you have worn a CGM for any length of time, you have almost certainly had a sensor fail before its labelled wear time. A 14-day Libre 3 that lifts at day 6. A Dexcom G7 that peels off in the shower on day 3. A Stelo that catches on a t-shirt and pulls clean off the morning you put it on.
It is frustrating, and at consumer prices, it is genuinely expensive. A sensor that fails on day 3 of 14 is throwing away roughly 80 percent of the value of the device. Two failures in a month can erase the cost benefit of switching to a CGM in the first place.
The good news is that this problem is largely solvable. The CGM community has, over the past several years, converged on a small set of products and techniques that dramatically improve sensor adhesion. None of them are expensive. All of them are easy to apply. Once I learned about them, my own sensor failure rate dropped from roughly one in three to essentially zero.
Why sensors fall off
The factory adhesive used on CGM sensors is designed to balance several competing requirements: it has to stick reliably for up to two weeks, but it cannot be so aggressive that it damages skin on removal. It has to work across an enormous range of skin types, climates, and activity levels. And it has to be cheap enough to manufacture at scale.
The compromise that results is an adhesive that works well in average conditions on average skin, and starts to struggle as soon as conditions are anything other than average. Specifically:
- Skin oil and sweat. Both reduce adhesive grip. Anyone who exercises regularly, lives in a warm climate, or has naturally oily skin will see worse adhesion than the marketing materials suggest.
- Water exposure. Sensors are technically waterproof to specified depths and durations, but the adhesive itself softens with prolonged water exposure. Daily showers, swimming, and saunas are all hard on adhesion over a 14-day cycle.
- Friction. A sensor on the back of the upper arm will catch on shirt sleeves, towels, jacket cuffs, doorframes, and seatbelts dozens of times a day. Each catch puts shear stress on the adhesive that compounds over time.
- Individual skin chemistry. Some people simply produce skin oils that interact poorly with medical adhesives. There is no fix for this at the chemistry level — but it can be worked around by reinforcing the adhesion mechanically.
Almost all sensor failures come from one or more of these factors. The solutions below address each of them directly.
Before, during, after
Four products, used across three stages of the sensor lifecycle, solve almost every adhesion problem people run into. Used together, they form a layered defence that pushes wear time to or beyond the labelled duration — and keep the skin underneath healthy enough for repeated use over months and years.
Skin-Tac Wipes
Skin-Tac is a liquid medical adhesive applied to clean, dry skin before placing the sensor. It is the single most effective product for improving adhesion, and the one most consistently recommended by experienced CGM users. The wipe leaves a thin, slightly tacky film on the skin that meaningfully strengthens the bond between skin and sensor adhesive.
The application is straightforward. Clean the skin thoroughly with soap and water (not alcohol — alcohol leaves a residue some adhesives don't bond to well), let it dry completely, wipe a Skin-Tac wipe over the area where the sensor will go, let it dry until tacky (usually 30–60 seconds), and then apply the sensor as normal. The whole process adds about two minutes to sensor application and dramatically improves how long the sensor stays put.
One caveat. Skin-Tac is not gentle on sensitive skin, and removing a sensor that has been adhered with Skin-Tac generally requires a medical adhesive remover (or a generous amount of oil and patience). For most users this is a worthwhile trade-off; for people with reactive skin, it is something to test cautiously.
View Skin-Tac Wipes on Amazon →Skin Grip Overpatches
Skin Grip makes adhesive overpatches specifically sized for the most common CGM sensors — including Dexcom G7, FreeStyle Libre 3, and Stelo. The patch is a medical-grade adhesive sticker with a hole cut for the sensor itself, so the sensor's own adhesive still contacts skin while the overpatch reinforces the edges and adds a much larger contact area.
This is the workhorse of the CGM adhesion category. A Skin Grip patch is waterproof, breathable, and lasts the full sensor wear cycle in most conditions. The hole-cut design means the patch does not interfere with the sensor's own measurements or skin contact — it only reinforces the perimeter.
The patches come in a range of skin tones and a few neutral colours. They are typically sold in packs of 20 or so, which works out to roughly the cost of one or two replacement sensors. Most users apply a fresh overpatch when applying the sensor and leave it untouched for the full wear cycle.
View Skin Grip on Amazon →RockaDex CGM Patches
RockaDex is an Australian-founded brand that has developed a strong following among swimmers, surfers, and anyone whose CGM regularly faces aggressive water exposure. Their patches are made from a stretchier, more flexible material than most overpatches, which means they move with the body better — particularly during swimming or high-intensity exercise — and resist edge-lifting that defeats other patches.
RockaDex patches come in plain skin tones and in a range of decorative designs. They use a different adhesive from Skin Grip that some users find gentler on the skin during removal, though the trade-off is slightly less aggressive grip in extreme heat. The same hole-cut design protects the sensor's own contact patch.
If your sensor consistently fails after pool sessions, sweat-heavy workouts, or hot showers, RockaDex is generally the first patch to try. For everyday wear in temperate conditions, Skin Grip and RockaDex are roughly interchangeable — the choice often comes down to which adhesive your skin prefers.
View RockaDex on Amazon →La Roche-Posay Cicaplast Baume B5
The fourth product in the stack is not an adhesion product. It is what to apply after the sensor comes off, before the next one goes on.
Medical adhesives — even the gentler ones — leave skin slightly compromised after a 14-day wear cycle. Mild redness, dryness, and occasional flaking are normal. Most people just apply the next sensor a few centimetres away and do nothing about the previous site. That works in the short term. Over months of repeated wear, it can lead to genuine sensitisation, slow-healing patches of skin, and eventually fewer viable sites for the sensor to go.
Cicaplast Baume B5 was designed for exactly this — compromised skin barriers that need to repair faster than they would on their own. The active ingredients are panthenol and madecassoside, both well-researched for supporting skin barrier recovery. It is fragrance-free, suitable for sensitive skin, and far more substantial than the marketing-led "after-care" products that fill most pharmacy shelves.
For CGM users, the practical pattern is simple. When you remove a sensor, clean the area gently and apply a thin layer of Cicaplast. Reapply once or twice over the next 24 hours. By the time you cycle back to the same site in a few weeks, the skin will be ready for it. Sensitive-skin users will notice the biggest difference — but everyone benefits from rotating into healthy skin rather than slightly damaged skin.
STRENGTHS
- Designed for compromised skin barriers
- Active ingredients (panthenol, madecassoside) with research support
- Fragrance-free, suitable for sensitive skin
- A small tube lasts months
- Extends usable site rotation over the long term
LIMITATIONS
- Higher price point than basic moisturisers
- Not strictly required if you have unlimited rotation sites
- Most easily found in pharmacies and online, not supermarkets
The application protocol that works
Combining the products correctly matters more than any individual product. After reading widely and talking to long-term CGM users, this is the protocol that consistently produces the best adhesion results.
- Choose the right placement. Avoid sites where clothing or seatbelts will rub repeatedly. The back of the upper arm, slightly higher than the manufacturer's suggested location, generally has less friction than the standard placement.
- Clean the skin properly. Wash with plain soap and water. Avoid moisturisers, lotions, and oils for several hours before application. Some users find that a quick alcohol wipe followed by full drying improves results, though others find Skin-Tac alone works better.
- Apply Skin-Tac to the area. Wipe Skin-Tac across the application zone. Wait 30–60 seconds for it to dry to a tacky, non-wet finish.
- Apply the sensor. Use the manufacturer's applicator as directed. Press firmly around the entire perimeter of the sensor for 30 seconds to encourage good initial adhesion.
- Apply the overpatch immediately. Skin Grip or RockaDex — whichever you prefer. Smooth out from the centre, with the sensor passing through the cut hole. Press the perimeter of the overpatch firmly into the skin.
- Avoid water for the first hour. Adhesives reach maximum strength after a brief curing period. No showers, swimming, or hot baths in the first 60 minutes after application.
If a sensor lifts mid-cycle, do not try to push it back down. The adhesive bond, once broken, will not properly reform. Instead, place a fresh overpatch on top of the existing patch — the new adhesive will hold the assembly in place for the remainder of the wear cycle.
When you remove the sensor
The application protocol gets most of the attention, but what you do at removal matters almost as much over the long run. A site that comes off cleanly and is allowed to recover properly will accept the next sensor better, and will keep accepting sensors for years. A site repeatedly stripped of intact skin will not.
Loosen the adhesive before pulling. A few minutes of warm water in the shower, or a small amount of baby oil rubbed gently around the edges, lifts most of the bond before the peel. Pulling at a sensor that is still firmly stuck is the fastest way to leave a raw, red patch that takes weeks to heal.
Once the sensor is off, clean the site gently with plain water. Pat dry. Apply a thin layer of Cicaplast Baume B5 to support the skin barrier as it recovers. Reapply once more 12 hours later if the area is still red. Then rotate to a fresh site for the next sensor. By the time you cycle back to this site in a few weeks, it will be ready.
What does not work
A few things commonly recommended online are worth avoiding:
- Generic medical tape (such as zinc oxide tape or surgical tape) often produces stronger initial grip but a much harsher reaction on removal. The CGM-specific overpatches above are designed for the longer wear time and are gentler on skin overall.
- Superglue or other consumer adhesives should never be used. Aside from being unsafe on skin, they can damage the sensor's own electronics.
- Reapplying a partially detached sensor with extra adhesive on top. Once the sensor has lifted enough to lose skin contact, the readings become unreliable. The right move is to replace the sensor and use a fresh adhesion protocol from the start.
Closing thought
I include this guide because I genuinely wish I had read it before my first CGM. The cost of a failed sensor is high, the friction of getting the application right is low, and the products that solve the problem are widely available and inexpensive.
If you are already using a CGM and finding adhesion unreliable, start with Skin-Tac. Add an overpatch. Adjust placement. Use Cicaplast between cycles to keep the skin healthy. The combination almost always works, and once you find a protocol that fits your skin and lifestyle, sensor failures stop being a regular event — and the skin underneath stops being something you have to think about.