My frown lines are slightly worse after botox even though I am barely able to frown. What could be the problem?

Thank you for your question.  If your frown lines appear worse than prior to your treatment and your truly have minimal muscle movement, you may require a filler under these deep lines.  Expert placement of filler, such as hyaluronic acid (Juvederm Ultra, Restylane) under deep lines can "pop them out like a dent in a car fender".  I find that what works well in patients like yourself is adding filler 2 weeks after an optimal Botox treatment in which the muscles have minimal active motion, but deep wrinkles remain.  Regular Botox treatments every 4-6 months will stop the deep wrinkles from reforming and you may only need additional filler every 1.5-2 years.  Please mention this to your injecting physician, or seek consultation with an expert injector board certified plastic surgeon or dermatologist in your area.  Best wishes!

This sounds unusual. Can you post pictures to illustrate what you are describing?  Full results are seen at 14 days.