Henna tatoos usually last anywhere from 1 week to a month, depending on how well you take care of them. Mine usually last about 2 weeks. You need to let your henna tatoo dry at least 6 hours, preferably overnight. If the person really knows what they're doing, they'll apply a coating of sugar and lemon juice 15 minutes after application to create a glaze (the henna crust won't come off as easy). Then, the next morning, use a spoon and oil to get the crust off. The tatoo will be orange at first, but over a couple days will turn brown. DO NOT get black- ONLY brown. You should try to avoid swimming in chlorine, but if you have to, apply vaseline every hour or so. Same thing goes for before you get in the shower or bath. Water will fade the stain quicker (or anything that removes skin cells). Also watch out for sweating. Get the tattoo someplace where you're not going to sweat constantly (ie. your arm instead of your lower back). Hope this helps!