Hello dear friend of HCM! I have gone through your query and understood your concerns! Thank you for sharing them on healthcaremagic. Synthroid is a hormone taken when somebody s thyroid gland is unable to produce enough hormone to maintain a normal function of body metabolism. Being so important means that it may cause metabolism malfunctions in two directions, in decreased and increased levels. The same thing is real for the substitutes produced by laborator. So I would say yes, your concerns might be due to a side effect of the pill you are taking or due to an inappropriate dose of the medication. Between the common side effects of Synthroid are, irregular heartbeats, irritability, fatigue, skin itching or redness, abnormal blood pressure, menstrual disorders in women, etc. So I would recommend your to go through a dosage of the hormone in your blood and a consult to your endocrinologist to evaluate this medical condition and get the appropriate decision if your are going to change the dose, change or quit that medication. I hope this answer was helpful to you! I would appreciate a lot if you rate as helpful my answer and write a short review about your experience with me. Thank you and best regards! DR ERIOL