Not sure as I have
I used this for the full 28 days but with my own serum and not the one recommended by face gym. I think my skin took some adjusting as initially it was quite dry after using it and I didn't really see much improvement. After around 2 weeks my skin seemed much happier after using it and I did start to notice a slight reduction around the fine lines by my nasolabial folds. I did feel I looked slightly younger but I wouldn't say I had a drastic improvement. It was easy to use and delivery was super fast . I would use again but due to the cost it is not something I would be able to purchase often.