The adverse reactions of levothyroxine
sodium ( Thyronorm) include muscle cramps
, sleeplessness, intolerance to heat, and nervousness. Weight gain, constipation and loss of libido are not features. You should exclude other causes like diabetes since you have also gained weight and refractive error
. The drug cannot be stopped at once as the requirement may be lifelong for most people and the dosage needs to be adjusted tome to time in consultation with your endocrinologist
. Take care.