Java lovers, you may be in for a brewed awakening. • • You can save this article by registering for free here. Or sign-in if you have an account. (Washington Post illustration; iStock) jpg We independently select everything we recommend. Buying through us may earn us a commission, which supports our work. How long does caffeine stay in my system? If I drink an afternoon cup or two, will it mess with my sleep? Don't have an account? Create Account Java lovers, you may be in for a brewed awakening.