Customer reviews from Garmin
Garmin - Index Sleep Monitor Size: L/XL - Black - (2025)
Average customer rating
3.3
(202 Reviews)
Rating breakdown 202 reviews
5 Stars
59
4 Stars
43
3 Stars
36
2 Stars
26
1 Star
38
Customer Reviews for Garmin - Index Sleep Monitor Size: L/XL - Black - (2025)
Customer Rating
3
confusing
on January 5, 2026
Posted by: weav
Very confusing using this product if you have a Garmin watch. The watch prevails if you wear it overnight and you will lose any sleep monitor data There is no mention of this in the instructions and I had to call Garmin. The best I can determine is you have to take off the watch at night if you use the sleep monitor. Make sure you put the watch in sleep mode at night or it will track the non use data. Very disappointed with Garmin. Also I am not so sure about the pulse Ox accuracy in both the watch and the sleep monitor. I compared with a traditional digital device and it was off by 2-3 units (watch=94-95%, digital=97-98%). This makes sense as finger tip/nail bed has more capillaries to determine accurate Pox.
Written by a customer while visiting Garmin
Customer Rating
4
The Index Sleep Monitor works very well.
on January 4, 2026
Posted by: Yoyi
I was able to use it for two weeks I but had to stop using it for the past 3 days because it created a rash on my right bicep. I believe that dermatologists call this rash "contact dermatitis". Do you have other customers with the same problem. Will the monitor work properly if I inser3t a piece of cloth between its sensor and my arm? Will try using it tonight.
Written by a customer while visiting Garmin
Customer Rating
4
Not bad!
on December 29, 2025
Posted by: Lola B
This is way more comfortable than wearing a watch to sleep. I’m glad I bought this!
Written by a customer while visiting Garmin
Customer Rating
3
Does what it needs to do
on December 27, 2025
Posted by: Reviewer 808
I am part of the Garmin ecosystem but I didn't love wearing the watches at night. This is comfortable but overall product experience isn't totally thought through. Charging isn't the most convenient due to the connector and armband, and the software integration is really dependent on the watch/and patience that you have. For a first gen, it's fine but not a real competitor to other non watch based sleep/health products.
Written by a customer while visiting Garmin
Customer Rating
3
Half-Baked
on December 23, 2025
Posted by: Panglossian
I'm a Garmin loyalist and understand that the upper arm is a superior sensor location for PPG HRV, RHR, etc., and I wanted to give my wrist a break from wearing my expensive Garmin watch. Alas, the first generation version of this is poorly supported, the sync is screwy, and you have to baby the devices each evening and each morning to try for the best hand-off. I expect it'll improve, and the next generation version will probably make me want to upgrade. I almost returned the ISM, but decided to stick with it a little longer. Crossing my fingers.
Written by a customer while visiting Garmin
Customer Rating
5
Great addition to Garmin
on December 20, 2025
Posted by: Brxx
I have been using it for a month now , it is way better than my fenix watch both in terms of comfort and sleep metrics. The biggest difference I see is in blood oxygen % , that metric on my fenix 6 was really unreliable. I was hasitant for quite some time because of the armband thing but it turned out it is perfect , I can’t feel it when I sleep , even when I move in bed it does not bother me at all. As advertised the fabric is soft and stretchy , the whole device is smaller (which is good) than I expected. One thing I found is that when you forget to take off your watch for the night (I was too tired) the app reads it from the watch and not from armband. Overall I am pleased with this product and its integration into the ecosystem. Except for few glitches when syncing the devices no issues.
Written by a customer while visiting Garmin
Customer Rating
1
The Worst garmin product
on December 15, 2025
Posted by: MJawa
I am a Garmin user for almost 20 years. Used many watches and gadgets. This is simply the worst product. I was never able even to connect.
Written by a customer while visiting Garmin
Customer Rating
5
Pairs well with the Garmin Connect app
on December 14, 2025
Posted by: Mwebb
Much more detailed readings than with just the watch. I pair this up with a garmin Instinct and have been very impressed with the ease of use and depth of information that this monitor has to offer.
Written by a customer while visiting Garmin