What are the effects of using coffee?

What are the effects of using coffee?
Up to 400 milligrams (mg) of caffeine a day appears to be safe for most healthy adults. That's roughly the amount of caffeine in four cups of brewed coffee, 10 cans of cola or two "energy shot" drinks. Keep in mind that the actual caffeine content in beverages varies widely, especially among energy drinks.Women who are pregnant or who are trying to become pregnant and those who are breastfeeding should talk with their doctors about limiting caffeine use.

You drink more than 4 cups of coffee a day

You may want to cut back if you're drinking more than 4 cups of caffeinated coffee a day (or the equivalent) and you're experiencing side effects such as:

• Migraine headache
• Insomnia
• Nervousness
• Irritability
• Restlessness
• Frequent urination or inability to control urination
• Stomach upset
• Fast heartbeat
• Muscle tremors