The onset of results for Botox treatments vary with individuals as well as the area of the body treated. Generally, Botox is expected to start having visible effects within three to four days after injection. Some patients may see the results earlier while it could be delayed for some others. On the average, it takes about 2 weeks for maximum results to be seen. So if you are planning to have a Botox treatment to get you ready for an event, tailoring the treatment to about 2 weeks prior to the event would be a great idea. You would be experiencing the full effect of the drug by then and whatever bruise or discomfort you may get from the administration would have been long gone by then.