I think it is very strong, I use water-based serum, and when you massage with this product, the muscles pull and shake. The first time I used this, it started smoking in one eye, and I was scared because of this. Then I passed this over my forehead, and the muscles pulled from the head, and the days after I had pain like a pressure in my head. When I massaged under the cheeks, it hurt my teeth :(
I don't know if it's just me or if it's common or if there's something wrong with the device.
1 product in post Is there a problem with the product?