Botox can be used as an off-label indication for neck lines. I find that it does reduce the hanging vertical folds to some extent in many patients, but not comletely. It might be my technique, but I do not find it very helpful in horizontal neck bands for the majority of patients whom I have treated.
Botox can definitely be used to improve the appearance of the aging neck. While not approved yet, it is very effective in treating what is called "platysmal bands", not true wrinkles. So what are platysmal bands?! Try saying an exaggerated and prolonged letter "E" out loud and look in the mirror... see those tense vertical strips along the front and side of your neck? Those are your platysmal bands! As we age, these become more prominent even at rest, without those intense expressions. Botox is a fantastic way to relax that neck muscle, making those bands much less apparent. While it improves the overall appearance of the neck, it is not directly addressing laxity/sagging, crepey skin, or horizontal lines and wrinkles. Depending on the severity of the bands, a good amount of Botox (usually about 5-10 units per band, and sometimes more) is often needed to have a dramatic effect. See your board-certified provider to see if your neck could benefit!