Henna can last anywhere from 1 to 3 weeks depending on how long the paste sits on the skin, how warm the environment is, and the aftercare applied to the skin after the paste is taken off.
How can I make it last as long as possible?
Letting henna paste sit on the skin as long as possible is the best way to get a beautiful, dark stain that is long lasting. The minimum amount of time you want the henna paste on your skin is 2 hours. It is strongly recommended that you keep it on your skin for 6-12 hours. This will get the best stain. While letting the paste sit, it is best to keep the skin in a warm environment.