I had mine done 9 years ago, and a top up around the crown about a year in. Nothing since then. It has held up, and I don't really go out of my way to use sunscreen unless it's extremely sunny or I know I'll be out for a long period of time. I actually tried to deliberately fade the edge of my hairline (I always felt the dots are slightly too big there) by wearing a specially shaped kitchen foil helmet that only exposed about 5mm of hairline inside a sunbed. I did this several times a couple of years ago and I don't think it made any difference although I am going to try again this week and try tilting my head different ways. I ended up dealing with my hairline concerns by using concealer. I think if a treatment is going to fade it will happen within the first few months. I got my top up because that first year I was out all the time in the summer, wearing a trucker cap that was only mesh at the back, and I noticed crown fading. But after that top up I didn't do anything different and it hasn't faded. The cases I've seen with bad fading have all happened very soon after the treatment and the poor guys have had to go back over and over. It's normal for both dot size and darkness to fade maybe 30% in the weeks after a treatment and it makes it look more realistic, but it shouldn't fade more than that long term unless you are just a bad candidate.