Helped Over 500,000 patients with 98%+ satisfaction.

Connect & Get Personalized 1-to-1 Answers from Expert Doctors

DoctorSpring > Question Home

How long to wait for test after single LEVOTHYROXINE.

Resolved Question:

Hello,

If someone has tried a single dose of 0.05 mg of Levothyroxine once (for the first time) out of suspicion that they have hypothyroidism, how long should they wait before taking a blood test in order to get an accurate result? I believe the normal half-life of levothyroxine is 7 days for euthyroid individuals.

Thank you,
Sean

Category: Endocrinologist

Ask Your Own Question

Category: Diabetologist
 25 Doctors Online

Hello,
Thanks for your query at DoctorSpring.com
I understand your concern
It takes 2-4 days for drug to achieve peak blood levels if it was taken intravenously so you can check elevated blood level by taking test at that time. But if you really had hypothyroidism improvement in symptoms will be seen only after many weeks of use. You are right that in euthyroid individuals half-life is 7 days and you can see elevated blood levels during this time.
Hope it was helpful
Please feel free to discuss further
Regards


Patient replied :



In order to avoid a false "normal" result due to the one dose of 0.05 mg of levothyroxine, how many days should one wait to take the blood test?


Hello,
You should wait at least 24 hours to get to see elevated levels of the hormone in your blood
Regards


Patient replied :

Hello, just to be clear, in order to see levels NOT effected by the levothyroxine use, how long should one wait to take a blood test and receive results--as if they had never taken levothyroxine. It is for the purposes of initially diagnosing hypothyroidism. Thank you.


Hello,
You should wait 2 to 3 weeks after levothyroxine use for hypothyroidism test
Thank you


Dr. J Muthukrishnan
Category: Diabetologist
Experience: 
Fellowships/Training: 
1. 10th Asia-Pacific Pediatric Endocrine Society  Fellows meeting, Seoul, Korea, Oct 2008
2. Eighth ICMR Course on Genetics and Genetic Counseling – Jul 2008 – SGPGI, Lucknow
3. Annual Certificate Course on Endocrinological Laboratory Techniques at National Institute of Nutrition (ICMR) Hyderabad,India, ( Aug-Sep 2006) 
Fellowship: Endocrinology, Diplomate of National Board, National Academy of Medical Sciences, New Delhi, 2008, Medwin Hospital, Hyderabad
Senior Residency: Diplomate of National Board (General Medicine), National Academy of Medical Sciences, New Delhi, 2002
Residency: MD, General Medicine, 1997-2000, Armed Forces Medical College, 2nd position in University
Medical School: MBBS, Armed Forces Medical College, 1992
Dr. J Muthukrishnan and 4 other Medical Specialists are ready to help you

Users who read this, also read:

Make informed and better medical decisions.

Join the 500,000 people who found a smarter, quicker way to get Answers, Recommendations & Expert Opinions.

Expert Doctors at fingertips

Recommendation on next step. Second-opinion.Multi-specialty.

Save Time

Average time for answers: 6 hours.

Save Money

$35 for typical specialist consult vs. $120 for a local appointment.

Free Follow-ups

Clarify, ask further questions for free in private conversation.

100% Satisfaction

Money back guarantee for the 1st reply. MEDNET Quality Board.

Start My Consultation

CHAT NOW

About DoctorSpring.com

Doctor Spring is a novel online Doctor consultation platform where you can get your medical questions answered by leading Doctors. Just Submit your question and rest assured that you will consult a Doctor easily. Once you submit the question, the Doctor from the concerned specialty will reply within hours. You can always ask more questions or add details with follow-up question options and make it an online doctor chat. You may use this service to consult a specialty or for getting medical second opinion. All paid services come with a MEDNET quality assurance and 100% money back guarantee.

DoctorSpring in news