I did experience, at least in the short term, possibly some effects from this mask. Mostly that the skin felt smoother immediately after and the day after use. It was a temporary feeling, and I don’t know how it would have lasted over time.
The problem I had that made me stop using the mask was that the light was SO strong. I don’t consider myself extremely light-sensitive in general (although I do like to wear sunglasses if it’s midsummer or abroad), but I absolutely could not use this mask with my eyes open. Even with my eyes closed, the light felt uncomfortably strong to the point that I didn’t want to have the mask on.
I finally tried wearing a sleep mask over my eyes underneath (like the kind you wear on a plane), and then it was manageable but still clearly strong. The protective mask I needed to wear under the mask also covered the skin areas around the eyes that you might otherwise have liked to treat with light if it had been possible.
In summary, I don’t know if it works in the long term, but in the short term, it didn’t for me. Maybe this applies to all LED masks (I haven’t tested any other models), but since it’s a somewhat expensive product, it might be worth asking to try it at a friend’s place if you know someone who has one before you buy it yourself. I sold mine.