Can teens drink coffee or not? There is no clear line on this one. According to research. Caffeine does not hinder the growth and development of children. But too much caffeine can cause hyperactivity, insomnia, nervousness, nausea, headaches. Anxiety. Symptoms such as irregular heart rate. According to experts it is recommended that adults should not exceed. 200 to 300 milligrams per day. But again, no data is given on how much caffeine children can receive per day. Probably the strictest regulation of coffee is in Canada. Health Canada recommends no more than 45 milligrams of caffeine per day for children between the ages of 4 and 6, 62 milligrams per day for children between the ages of 7 and 9, and 85 milligrams per day for children between the ages of 10 and 12. Teenagers should not consume more than 125 milligrams of caffeine per day. And the amount of caffeine can vary from one coffee drink to another. If you must want to drink coffee as a teenager, my advice is this. Don't drink it often. Drink less.