Typically they don't work on type 4 hair. But there's a wide range of texture within the 4 category. If your hair is type 4 and very soft/fine you might get results. If you think they might work for you, the only way to find out if you're curious enough is to test a swatch of your hair - and if you have cut hair even better. I don't recommend applying it if you haven't tested a swatch first.
