What Is The Normal Thyroid Range While On Synthroid?

Posted on Wed, 6 Jun 2018

Medically reviewed by Ask A Doctor - 24x7 Medical Review Team

Wed, 6 Jun 2018 Answered on

Fri, 30 Apr 2021 Last reviewed on

Question : I have been on Synthroid for about 15 years. I am taking 150mcg. What is the normal range for your thyroid numbers and what do they mean when it is high.

Answered by Dr. Mirjeta Guni (1 hour later)

Brief Answer:
About levothyroxine dose;

Detailed Answer:
Hello and thank you for asking
The normal range of TSH is 0.4-4.2.
A TSH higher than normal means that the dose of levothyroxine is low or you do not take it appropriately (fasting in the morning and for 1 hour nothing to eat or drink).
If you have been taking it correctly and TSh is still high, your physician will increase the dose depending on TSh.
Hope i have been helpful.
Kind regards,
Dr.Mirjeta

Above answer was peer-reviewed by : Dr. Nagamani Ng