For residents seeking the Fountain of Youth in Baltimore, botox can be the cosmetic procedure of choice. How does botox work? By paralyzing muscles at the injection site, such as the forehead or laugh lines, and in turn creating a smooth, wrinkle-free appearance. How long does botox last? Most injections last up to four months, with many clients opting for regular appointments to maintain the youthful appearance the noninvasive procedure grants them. Those concerned about side effects of botox can heed the experiences of most practitioners and regular clients, who report minimal ones that may include mild redness or bruising.