Loose/excess forehead skin. Fixes? (Photo)

The issue isn't so much loose or excess skin. Rather, the issue is alot of contraction of the forehead muscles. This creates the horizontal lines and corrugation that trouble you. Botox is typically the best option for this issue and the results last 3-4 months. An experienced injector can eliminate that look without completely freezing your forehead expression. Good luck!Stephen Weber MD, FACSDenver Facial Plastic Surgeon

You do have some deep lines for 18yo.  You must use your forehead a lot when speaking.  If these lines bother you then you may want to consider some Botox to the forehead.  This will help to decrease the movement in this area and soften the lines.  It works well - only drawback is you need to keep doing it every few months.    

Forehead lift, also referred to as brow lift, is best performed on patients with loose, saggy skin in the upper third of the face.  And based on your photos, the surgery might be too invasive because it appears that your problem is caused by excessive muscle contraction that results in deep facial lines.  For this reason, Botox injection might be a better option, although its effects are only temporary (four to six months).Good luck and best wishes.