Patient description: The patient is a 33-year-old woman complained of fatigue, weight gain and abnormal spotting between menses. No hirsutism or nipple discharge was detected. Her BMI was 34. Her lab results were remarkable for high TSH level (13 mU/L) and low free T4 level (0.2 ng/dl). Her anti-TPO levels were extremely high (120 IU/ml). She was diagnosed with Hashimoto's thyroiditis. Her aunt, brother and mother have the same disease. After starting 250 mcg Levothyroxine per day, her symptoms improved significantly and her periods are normal. She is still overweight with BMI of 31. Her most recent thyroid profile revealed all results except for anti-TPO within the normal range: TSH: 2.35 mU/L Free T4: 2.7 ng/dl Anti-TPO: 75 IU/ml

Clinical trial eligibility criteria: eligible ages (years): 18.0-50.0,  Healthy To have freely agreed and signed the consent form, after all essential elements of the protocol have been clarified, before any procedure Body Mass Index (BMI) of the research participants must be comprised within the range of 18.50 to 27.00 No abnormal findings on medical history that, in the opinion of the investigator, constitutes a risk or a contraindication for the participation of the participant in the study or that could interfere with the study objectives, conduct or evaluation Normal vital signs: heart rate between 50 and 100 beats per minute; Systolic pressure between 80 and 129 millimeters of mercury (mmHg); diastolic pressure between 50 and 89 mmHg; temperature between 36.0 and 37.0 degrees Celsius Electrocardiogram (ECG) normal (abnormalities, even if clinically not relevant, are not permitted [example {e.g.}: PR, QRS, QT, QTcF] should be within normal range, no conduction abnormalities etcetera [etc.]) All values for biochemistry and hematology tests of blood and urine within the normal range or showing no clinically relevant deviation as judged by the Investigator Other protocol defined could apply  Supplementary tests results out of the values considered as normal, unless considered clinically irrelevant Research participants who are submitted to surgery before the beginning of the study will be carefully evaluated by the doctor regarding the enrollment in the study complying to an period ranging from 4 to 8 weeks Positive test for hepatitis B, hepatitis C, or human immunodeficiency virus (HIV) in pre-study tests Participants with a history of hypersensitivity/allergy to study drug or excipients, history or presence of asthma or any serious allergy (requiring hospitalization or prolonged systemic treatment), any food allergy or intolerance which in the opinion of the Investigator represents a safety risk (e.g., iodine allergy, etc.) Has participated in any experimental trial or has taken any experimental drug within 6 months previous to this study (RDC [resolution of the collegiate board] Resolution 34, dated June 3, 2008) Participants that prior to the dosing takes any other medication and had not passed at least seven half-lives of elimination of the drug, in this case, be considered by the Principal Investigator the non-inclusion of the participant in the study. Participants taking medications known to affect thyroid hormone metabolism, e.g., oral contraceptives, hormonal implants, parenteral hormones, anabolic steroids, androgens, etc., or the bioavailability of levothyroxine like proton pump Inhibitors Has a history of alcohol abuse or has ingested alcohol 24 hours previous to the hospitalization period Other protocol defined could apply