I had a botox injection for piriformis syndrome 15 days ago and no result yet. More intense pain than usual. How long before I give up hope?

Never give up! But the Botox does most of what it is going to do within 3-7 days and all it can do within 2 weeks. Might need a bigger dose before you decide it won't help.
Nteresting. Botox shows results in 5-7 days most of the time. If you don't get resou may have to have Botox repeated. Good luckults in one more week y.
Don't. The Botox did't work this time. Piriformis syndrome is hard to treat-consult the dr and see if they think another round of that treatment or another is wise.