I finally mustered the courage to have my now rather thin lip injected. It took me so long because I only know of badly done lips. But the doctor said at the first consultation that he very often and gladly performs this treatment and that he places great value on natural-looking results.
I could hardly believe that the treatment really doesn't hurt. My result after one treatment turned out very nicely, and so did my friend's, who was also treated. Now I also have the option of a free follow-up check, in which any corrections can possibly be made.