If you regularly consume caffeine and haven’t recently: caffeine.
If you regularly consume nicotine but haven’t recently: nicotine.
If you regularly consume any drug, really, but haven’t recently: youre probably experiencing withdrawal; the most common side effects from withdrawal of most substances is a headache.
If you regularly consume caffeine and haven’t recently: caffeine.
If you regularly consume nicotine but haven’t recently: nicotine.
If you regularly consume any drug, really, but haven’t recently: youre probably experiencing withdrawal; the most common side effects from withdrawal of most substances is a headache.