“Worked well for a few years, now it doesn't paralyze muscles as in the beginning :(”

Botox is certainly worth it, when it is working for you and your muscles respond to it. It's fabulous- Hoewever
After 4 years of getting treatments 3-5 months apart, the frown lines ( between eyes, the #11 etc), are back because my body has built up antibodies to the Botox. I get slight paralysis, but only for about 4-6 weeks and then it's gone. Nothing like it worked the first few years. Such a shame to start at 39 and by 43 when I really start needing it, it's no longer an option for me.
I worry about these poor gals starting Botox in their 20's and what they will do if they build up a tolerance, as I have to Botox. Maybe they will create something new by then.
And BTW, I had to call Allergan to talk with them about this, because my plastic surgeon would not admit to me that the drug was not working and why! He wanted to inject more and more costing me more for less results.