One jar will definitely lock up the average user's hair to start, and have enough left to maintain it for a few weeks at least after. If you have super long and thick hair, or are wanting to do a lot of tiny dreads, think about grabbing a second jar. Or if you want, order two jars even if you don’t have long or thick hair, just so that when you run out, you don't need to order online and wait again for it to arrive.