BOTOX (R) was the product developed in a line of treatments known as neuromodulators. It has been used since the 1970s for various medical conditions in the head and neck including migraine headaches, difficulty swallowing (dysphagia), excessive sweating, sweating when eating, eye twitching, muscle spasms, overactive bladder, etc.. It works by inhibiting the action of muscles. For cosmetics this can be used to your advantage by selectively inhibiting muscles that cause wrinkles. Common locations for its use include the forehead, the area between the eyes (glabella), the areas next to the eyes (crow's feet or lateral orbital rhytids), the bands of the neck (platysmal bands) and the mid portion of the nose (bunny lines). Other areas it can be used include to soften the fine wrinkles around the mouth, the dimples of the chin that develop when you talk, and the muscles that cause frowns (depressor anguli oris) in order to help turn up the corners of the mouth.
There are several drugs in the same class as BOTOX (R) including Dysport and Xeomin. Each manufacturer determines what a "unit" of each medicine does, and there is not a comparable relationship between unit amounts required for each treatment area. In other words, 1 unit of BOTOX (R) is not the same as 1 unit of Dysport, and you would need more units of Dysport to get the same result as BOTOX (R). Whereas neuromodulators can be very helpful for the right patient, it is not for everyone. It can be used to help improve the results of more invasive treatments such as surgery or skin resurfacing. And most surgeries do not get rid of the need for further neuromodulator treatments as surgery addresses what you see at rest, but neuromodulators address what happen with motion. This can all be discussed at the time of your consultation with Dr. Guy.