Ritalin tablets:
Administer in divided doses 2 or 3 times daily, preferably 30 to 40 minutes before meals. Average daily dosage is 20 to 30 mg. Some patients may require 40 to 60 mg daily. In others, 10 to 15 mg daily will be adequate. Patients who are unable to sleep if medication is taken late in the day, should take the last dose before 6 p.m.
this should be under a doctor's supervision.
I am 18 years old and weight 180 pounds. I have been diagnosed with add, my doctor started me on 30mg capsules, after a couple of weeks i did not think that the 30mg really effected me so i told my doctor and she upped me to 2 capsules a day for a total of 60mg. Most likely since you are an adult they will start you at 30mg. Im not a doctor though so i cannot say for sure.