Although many people begin preventive treatments in their 20s and 30s, there is no specific age at which you should begin them. Instead, it is best to pay attention to the skin issues specific to you. When you notice fine lines beginning to appear, you should consider Botox. Preventative Botox can prevent fine lines from becoming full-blown wrinkles. In most cases, Botox is recommended for patients aged 18 and older, and patients in their mid-20s and early 30s are considered to be suitable candidates for preventative Botox treatments. Any earlier than your mid-20s is probably unnecessary since you won't have enough wrinkles to worry about.