It is not uncommon for patients to develop wrinkles in the skin of their forehead in their twenties, or even younger. However, in answer to your question about whether tying your hair in a bun might be causing you to develop the wrinkles you see, the answer is no. Your individual genetics plays a large role in determining at what age you first notice horizontal wrinkles in the skin of your forehead. It is contraction of the frontalis muscle that causes these wrinkles to develop over time. Some people have stronger and more active frontalis muscles, while other patients have weaker ones, and perhaps some patients fire them more frequently, and others less so. The thickness of an individual's skin also influences how long it may take for a patient to develop these lines, and how deep they may become. Then too, some patients are just more observant, and, or, alarmed by the first appearance of such wrinkles in their forehead, whereas other patients, with the same degree of wrinkling, pay it no mind.Fortunately, there are some things you can do to make such wrinkles less prominent, and, perhaps, slow their progression. Certainly, the earlier you start to address these wrinkles, the better the chance that you can minimize their inevitable increasing prominence with time. Probably, the most important step for you to take now, is to try to avoid as much direct sunlight to the skin of your forehead as possible. This means wearing hats with wide brims whenever you are in the sun, but, more fundamentally, it means seeking out the shade, when you are in sunny places, as much as possible. Sunblock can also be helpful in protecting the skin from the skin damage caused by the sun over time. But we find that patients frequently overestimate the degree of protection that sunblock can actually provide their skin, and thus become less rigorous in minimizing the amount of sun their forehead gets when they are wearing it. We recommend using a sunblock with an SPF of 50 or greater. But the more important point is that studies show that due to perspiration, the wind, contact with hair, skin, fabric or other objects, most of the sunblock that patients apply to their forehead is gone within one and half to two hours after applying it. Therefore, when you do use sun block, remember to reapply it, at least every two hours, but, better yet, wear a broad brimmed hat or seek out the shade, or both, when you are in strong sunlight for a protracted period of time.Other factors that are under your control that might slow the advancement of horizontal wrinkling of the skin of the forehead include applying a regular moisturizer, keeping yourself well-hydrated throughout the day, and avoidance of smoking. Luckily, there is also a medical treatment that can minimize the appearance of horizontal wrinkles of the skin. This involves injection of a drug called a neuromodulator. A neuromodulator blocks the postsynaptic receptors for neurotransmitters on the frontalis muscle, weakening the strength of its pull, and thereby reducing the visibility of the horizontal wrinkles of the forehead skin. In the United States, there are three brands of neurotransmitters, Botox, Dysport, and Xeomin. Given in proportionate doses, they each have roughly proportionate efficacy in reducing the visibility of horizontal wrinkles of the forehead. Patients can usually gauge the first effects of the injected neuromodulator two to five days after the injection. The peak effect of the neuromodulator on the frontalis muscle may not begin until about two weeks after the injection. The duration of effect of these neuromodulators tends to range from three to six months. So the good news is that you can continue to wear your hair in a bun. The better news is that we have a treatment that can visibly and reliably diminish the prominence of the horizontal wrinkles of your forehead that are beginning to drive you crazy.