Question about Beurer EM 59

It depends on how well cleansed/greasy your skin is. For me it's between 10-20 times, for my girlfriend 5-10 times. I wash them after each use and hang them up briefly to dry.

The gel pads quite often, depending on the skin. I haven't counted but I clearly exceed 20x. The actual electrodes last much longer.

I have used them at least 30 times. Always well covered with the foil. They still work. I am very satisfied with the product.

the adhesion decreases significantly after the first 5 or so uses. But even with the reduced adhesion, it still works after about 15 applications (without washing and drying the contacts). Official information that can be found is about 20 uses. I really see that as the upper limit. But even if the edges no longer adhere so well, it still works well for me. However, I have mostly used the relaxation function and the intensity is not as high. It may be that it becomes too uncomfortable for the skin when higher currents flow over a smaller area of skin ...
After each use, I simply stick the protective film back on the contacts until the next application.

I have the part and wouldn't buy it again. Does nothing. I'd rather go to a physio who offers shock wave therapy.