Inclusion Criteria:  At least 18 years of age, inclusive, at the time of signing informed consent form. Hypothyroidism treated for >2 years TSH stable between 0.4 and 4.0 mIU/L for the past 6 months (at least 2 measurements)  Exclusion Criteria:  Abnormal TSH on screening Unwilling or unable to participate/sign informed consent Changes in thyroxine dose or any other medication in the previous month Severe obesity (BMI [body mass index] >35kg/m2) Other significant comorbidity: History of ischaemic heart disease, valvular defect, stent placement, heart failure, stroke or TIA (transient ischemic attack) Diabetes mellitus under OAD (oral antidiabetic drug) or insulin treatment eGFR (estimated glomerular filtration rate) <60ml/min at screening, calculated by EPI formula History of liver disease, AST/ALT>3 times normal or GGT (gamma-glutamil transferase) >2 times normal or hyperbilirubinaemia at screening Systemic autoimmune condition currently under treatment (RA [rheumatoid arthritis], lupus, systemic sclerosis etc.) Active malignancy