Thank you for your question pepita84. I understand your concern. Botox is a purified protein used to address wrinkles associated with facial expression. When injected into the skin Botox will relax the muscles and smoothen out the overlying wrinkles. The most common areas of treatment are in the upper face. These include the horizontal lines seen on the upper forehead when one raises the brows, the vertical lines seen between the brows when one frowns (frown lines), and the crow's feet seen around the eyes when one smiles. The appearance of frown lines is variable from person to person. Usually they are in a vertical orientation but sometimes they can be oblique and sometimes a horizontal line is seen across the upper portion of the nasal bridge. The most common variation is to have two parallel lines, hence the common term "11's" to describe them. But some people have one, three, or more lines. Some people also will see a bulge in the area when contracting the muscle. This bulge is smoothened out after a Botox treatment. The pivotal studies used 20 units of Botox in the glabella area between the brow to address the frown lines. These studies demonstrated that the peak results are seen 14 days after the treatment and most people enjoy their results for 3-4 months. At that point, a maintenance treatment is recommended. While some people start to see results as early as the next day, it can take two weeks for full results so patience is important. We have our patients return two weeks after their treatment to assess their results via photographs. At that time additional units may be added if necessary. There have not been such studies published for the horizontal lines on the upper forehead. However, in my experience I find that 10-20 units works well in this area. For patients with narrow foreheads a lower dose may be used and those with a broad forehead generally require higher doses. I have also found that the full results in this area are seen by two weeks. Therefore, we have our patients return two weeks after their treatment to assess the results via photographs. At that point additional units may be used if further enhancement is desired. While Botox is one of the safest treatments offered, there are some situations where it is not appropriate. These include anyone who has an allergy to any of the inactive ingredients or who has had an allergic reaction to any botulinum product including Botox, Dysport, Xeomin, or Myobloc. The safety and efficacy of Botox has not been established in women who are pregnant, trying to become pregnant, or breast feeding. Therefore, women in these categories are advised to wait until breast feeding is completed prior to having a Botox treatment. Botox should not be placed in the skin on the site of an infection. Those who are taking an aminoglycoside antibiotic, an anesthetic, D-penicillamine, antimalarials, or immunosuppressants should not be treated, nor should those who have undergone chemotherapy within the previous six months. The use of antidepressant medications is not a contraindication to Botox treatment. It is important to avoid blood thinners before and after a treatment. These include both prescription and non-prescription medications such as warfarin (coumadin), aspirin, ibuprofen, alcohol, fish oil, vitamin E, and ginko biloba. Those with conditions that affect muscles and nerves such as amyotrophic lateral sclerosis (ALS or Lou Gehrig's disease), myasthenia gravis, or Lambert-Eaton syndrome should not undergo Botox treatments. In rare cases, some people are resistant to a certain neuromodulator such as Botox. In this case the treatment can be repeated using a different neuromodulator such as Dysport or Xeomin. With any injection, there are risks such as pain, bleeding, bruising, redness, swelling, tenderness, and infection. We take special precautions to minimize these risks such as using a painless technique. We also treat bruises with a laser as early as the next day. Bruises usually resolve within two weeks if untreated. After a laser treatment bruises usually resolve in 1-3 days, but may still take two weeks for full resolution. In addition to these risks, with Botox there is also a risk that the product spreads or diffuses to nearby structures. Spread to nearby muscles can lead to side effects such as the temporary appearance of droopy eyelids or a temporary asymmetric smile. After a Botox treatment, I recommend that my patients avoid heat exposure, alcohol consumption, and strenuous exercise for 24 hours and not lie down flat for four hours. This is because all of these activities may possibly lead to the movement of the product and consequent side effects such as droopy eyelids as described above. Although there have been no definitive studies shown that these actually occur and some physicians do not provide such aftercare instructions, in the absence of data I err on the side of caution and recommend that my patients avoid such activities. Please consult with a doctor for specific recommendations. Good luck!