Do Vyvanse And Synthroid Cause Weight Gain?

Posted on Thu, 12 Mar 2015

Question: I am taking 80mg of vyvanse and 50 mg of synthroid. I am also gaining weight like crazy. Is it possible it could be these two drugs interacting? Thank,you, XXXX

Answered by Dr. Panagiotis Zografakis (48 minutes later)

Brief Answer:
No such interaction

Detailed Answer:
Hello XXXX,

lisdexamfetamine (vyvance) and levothyroxine (synthroid) do not interact to cause weight gain. Vyvance may decrease your appetite and body weight. Synthroid is useful to regulate your thyroid function. If your thyroid function is not well regulated, weight gain may occur. Your TSH levels (Thyroid Stimulating Hormone) can confirm or exclude it. Low TSH levels may only cause weight loss. High TSH values may cause weight gain.

Very fast weight gain can also occur in edematous states. Edema means that water accumulates in body cavities or under the skin causing symptoms like shortness of breath, leg swelling etc. Such conditions may appear in heart failure, kidney disease, drug side-effects (not the drugs you're using) etc

I hope you find my answer helpful!
If you'd like to ask for clarifications, please use your follow-up questions.
I'll be glad to help more.

Kind Regards!

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Panagiotis Zografakis (14 minutes later)

Can too much synthroid cause the weight gain?

Answered by Dr. Panagiotis Zografakis (3 minutes later)

Brief Answer:
No, it's the opposite

Detailed Answer:
Hi,

too much synthroid will cause a low TSH (hyperthyroidism) and weight loss, trembling, nervousness, sweating etc
If you take less synthroid than required then TSH will rise and weight gain may occur.
I hope it's more clear now!

Kind Regards!

Note: For further follow up on related General & Family Physician Click here.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar