In General, Botox is the best for eliminating the elevens. However patients who are not interested in Botox can see substantial improvement using injectable fillers. My personal suggestion is to use both Botox and fillers for the initial treatment. It can provide a longjevity of approximately nine months with combined correction. Often the 11s do not come back to the same depth and can continue to be treated appropriately with either Botox or fillers down the line.
Neurotoxins like botox, xeomin, and dysport are really the best way to improve the appearance of the deep furrows that appear between the eyebrows. While some people have tried fillers in the past, I would not recommend this treatment because there have been many reported cases of skin necrosis and blindness because of improper injection into blood vessels in this highly vascularized area. Depending on the appearance of the rest of your face, forehead lifting may be another option to help improve the condition. Good luck!