Phentermine and Levothyroxine help

[Allyson007]

I am a 40 year old female who weighed 125lbs. for the last 10 years. Between May and July I went from 125 to 146. I am now at 151lbs. No change in diet and I joined a gym 3 months ago and have worked out religiously but continue to gain.

The unexplained weight gain is especially in my abdomen, which is very distended. My internist ordered a CT scan and ultrasound to look for fibroids, cysts, etc. Results were one small fibroid.

She also tested my thyroid which revealed a TSH of 4.270 and free T4 of 1.12. Initially, she wanted to just retest in 6 weeks. However, I brought her an article from the AACE that recommends treatment over 3.0. She was receptive to this and agreed to start me on 25mcg. Levothyroxine and retest in 6 weeks.

In addition to the Levo, the exercise, and a healthy diet, I also started taking 30mg. Phentermine to help get this weight off. It's a prescription I had leftover from a couple of years ago. I started both meds 5 days ago.

Questions: Do you believe that a TSH of 4.270 could explain my rapid weight gain of 25lbs in 3 months? My internist cannot find anything else wrong with me, except for the one submucosal fibroid. Is 25mcg a high enough dose to effect any real change in my TSH? Is taking the Phentermine at the same time as the Levo okay to do? My doctor does not know I'm doing this. Also, since starting these two meds 5 days ago I haven't felt very well; kind of spacey and fatigued. Any opinion about that?

My doctor said depending on what my TSH shows in 6 weeks, she may order an MRI to look at my pituitary gland and possibly refer me to an endo. Thank you for your time.

[Allyson007]

Thank you! That's very helpful information.

[Mark Lupo, M.D.]

if there are positive thyroid antibodies (TPO and Tg) and/or an enlarged thyroid, then it is worth treatment in many cases with TSH in this range.  If based on symptoms only, there may or may not be a benefit, so it ends up being a trial of medication.  I usually get the TSH to around 1.0 then re-evaluate benefit.

[Allyson007]

Do you think I should even be taking 25mcg. Levo for a 4.270 TSH?

[Mark Lupo, M.D.]

I do not believe the slight TSH elevation would cause this weight gain.  

I do not recommend taking meds that are not discussed with your doctor.  Would stop the non-prescribed med and go back to your doctor to discuss weigh-loss options.  Medications for weight are only a short-term solution to a long-term problem and most people regain all the weight when the med is stopped.

An endocrine eval may help determine cause of weight, but in most cases there is not an identified cause and it boils back down to eating habbits and exercise.