Nope, it would not help for your dark circle under eyes. It is a common problem for you to have dark circles under your eyes that makes you look older and not beautiful to cause you lost confidence. Coffee or any caffeine containing drink is probably one of the major causes of dark circle under the eyes for many people. Because of caffeine is a natural stimulant to cause your blood flow fast. You have to stop drinking any drink within caffeine if you wanna treat dark circles under your eyes. At the same time, you should replace coffee with regular glasses of fresh and mineral water to keep you well hydrated.
As far as I know, drinking coffee isn't good for reducing dark circles. In fact, drinking too much coffee maybe aggravate this symptom. There are many reasons for dark circles generation such as sleep deprivation and genetic factor. Drinking too much coffee will have influence on sleeping and caffeine will increase the accumulation of melanin. So you'd better not drink too much coffee.
If you want to reduce your dark circles, I advise you to guarantee your sleeping time and chose a suitable eye cream.
Of course not. On the contrary, coffee might result in and accelerate the formulation of dark circle. As you said, the key factor of your dark circles is lacking sleep, so why do not you get enough? there are several tips for reducing dark circles:
1. Go to bed right now, have enough sleep;
2. Stop drinking coffee, instead of fresh water or mineral water. If you will overnight, green tea would be a nice choice;
3. Have more natural foods containing VC, like fruit and vegs;
4. Adequate exercise to stimulate blood circulation, like jogging and massage.