Summary: If using too high a dose, levothyroxine can cause numerous side effects. Allergic reaction to “fillers” found in levothyroxine tablets can lead to swelling of the face, tongue or throat.Some of the more concerning levothyroxine side effects include ( 10): Temporary hair loss, particularly in children during the first month of therapy.However, when dosed correctly, the following side effects are less likely to occur ( 10): This means there is a small difference between having too little and too much levothyroxine. Most side effects from levothyroxine stem from doses that are higher than necessary ( 2).Įxcessively high doses can occur due to levothyroxine’s narrow therapeutic window. You must see your doctor to determine the best dose for you. Summary: Levothyroxine dosage varies between individuals, depending on age, weight and other medical issues. Typically it takes a few adjustments with your doctor before the dosage will be just right. The dose has to be adjusted based on blood levels, which is why your doctor must determine what you need.

In saying that, there are patients who can stabilize on 25-50 micrograms per day, and patients who require over 200 micrograms per day. Levothyroxine dosage depends on the patient.įor example the dose is typically lower in older patients than a middle-aged adult.Īs a ballpark range, a healthy adult with no other medical issues weighing around 155 lbs (70 kg) would usually require a dosage of 100 to 150 micrograms per day. It’s often not prescribed in cases of subclinical hypothyroidism, when no symptoms are present. Summary: Levothyroxine is used to treat hypothyroidism in children, adults and pregnant women. Some experts recommend not prescribing levothyroxine to treat subclinical hypothyroidism because of the high risk of serious side effects ( 8).

This condition is called subclinical hypothyroidism. Levothyroxine treats several different types of hypothyroidism including ( 3):īlood work can detect hypothyroidism even when symptoms are not present. Thyroid hormones influence several biochemical reactions in the body, including metabolic rate. Summary: Taken by mouth, levothyroxine is absorbed in the small intestine and then converted to the biologically active thyroid hormone T3. Thyroid-related blood work such as TSH levels will also return to normal ( 9). This means a reduction in symptoms such as fatigue, cold, weight gain, hair loss and impaired memory. Symptoms of hypothyroidism may reduce after several weeks of usage. Thyroid hormones increase basal metabolic rate and influence DNA transcription, protein synthesis and metabolism ( 7). Once in the body, levothyroxine (T4) is converted to triiodothyronine (T3), the most active thyroid hormone ( 6). Levothyroxine is taken by mouth and then absorbed in the small intestine ( 5).

Summary: Levothyroxine is a synthetic prohormone that is used to treat hypothyroidism. Some of the trade names for levothyroxine sodium include ( 4): Typically just referred to as Levothyroxine, it’s a synthetic drug that is biologically identical to T4, a prohormone produced by the thyroid ( 2, 3). Levothyroxine sodium is an oral medication used to treat - not cure - hypothyroidism ( 2). Summary: In hypothyroidism, the level of active thyroid hormones is lower than what is needed to maintain good health. Left untreated it can cause many health issues including fatigue, hair loss, poor memory and weight gain. It can result from insufficient thyroid hormone production or because thyroid hormones are inactivated before they have time to work ( 1). Hypothyroidism refers to an underactive thyroid.

Drug and Food Interactions with Levothyroxine.

Levothyroxine 50 mcg tablet