I am 40 and have had deep glabellar lines for at least 10 years, probably longer. I tried Botox several years ago and was not impressed. I have now had 2 Dysport treatments and am really happy with the results. There's no way I can get rid of the lines altogether, but they are almost completely gone. And now they don't jump out of every single picture, full of shadows! I no longer look stressed, angry, and/or tired (unless I am, of course). The results came quickly, within a week, and lasted at least 4 months. I got my second treatment at 4 months even though I probably could have waited a bit longer. I also like the way I have retained more facial expression with Dysport as compared to Botox.
At $200 every 4+ months, it's an investment I can afford to keep making, in order to prevent the creation of deep furrows over the years that are too far gone to do anything about by the time I'm 50 or 60.