So she, by her unqualified self, has determined that she has a thyroid problem and should self-medicate with synthroid for .. uh what purpose? I would agree that if you read some of the stuff on places such as about.com about being hypothyroid and the often occurring situation where a person appears to have the symptoms of hypothyroidisms but thyroid tests come back in the "normal" range, often on the edge of "normal" but still "normal". BUT, the appropriate recommendation if a person feels they need thyroid medication and the doctor who is returning results of "normal" that the person still feels are contestable, is to seek a second opinion from a doctor who is specifically qualified for this and also considers a tighter range of test result to be "normal" or "abnormal" (hypo or hyperthyroid).
It wasnt' stated why this friend decided to self-medicate with synthroid. If you look at many of the posts about T-3 used as a fat loss agent (and muscle loss!), synthroid is definitely not an option that will achieve such loss when thyroid medication is included in a cutting cycle.
I would strongly urge this person to go seek a second opinion the thyroid test results before deciding synthroid is the way to go, much less choosing the picking the dosage.
What exactly is the purpose?