Hi, My Thyroid Tests (on My Regular Yearly Physicals) Always

Hi, my thyroid tests (on my regular yearly physicals) always comes back low normal, yet there is nothing I can do to lose weight and the dr. says as long as it's low "normal" he doesn't want to prescribe anything.
I've been told by naturopathic dr's that they can give me things to increase the thyroid activity and stimulate the metabolism but it's really, really expensive. I am fully covered with extended health benefits that would cover this if a mainstream doctor would prescribe it.
What would you suggest please. I'm determined to get thyroid stimulation medication one way or the other.
Thank you.