Medically reviewed by Jessica Swirble, PharmDLast updated on March 26, 2025

Drug Information| | |

• Brand Name:Synthroid, Levoxyl, Tirosint, Depon Syn
• Generic Name:Levothyroxine
• Uses:Treatment of hypothyroidism
• Drug Class:T4-Thyroid Stimulating Hormone
• Availability:Prescription only
• Generic Status:Yes
• Controlled Substance:No

Synthroid contains Levothyroxine, a synthetic thyroid hormone. It is used in the management of hypothyroidism. It may be administered with or without food.

Levothyroxine is used to:

• Increases the number ofthyroid peroxidase (B- and T-cells) immunoglobulin light chain (IgL) antigens in thyroid tissue

Follow your thyroid's thyroid function tests and medications should be evaluated regularly to monitor thyroid hormone levels and to ensure the drug is working properly.

Levothyroxine is primarily used to:

• Treatment of certain adrenal gland disorders
• Treatment of thyroid disease affecting the thyroid
• Thyroid disease affecting the pituitary gland (also called pituitary-gonadal or thyroid gland-gonad Junction disease)

Levothyroxine works by thyroid stimulating hormone (TSH) which helps the body make thyroid hormone. This helps the thyroid gland make more thyroid hormone and can be used in combination with natural or expert>[,] non-prescription or prescription therapy

Levothyroxine is not recommended for use in patients with severe adrenal insufficiency

Levothyroxine should be used with caution in patients with severe adrenal insufficiency (1)

Levothyroxine is not to be used in patients with thyrotoxicosis (2)

Levothyroxine should be used with caution in patients with thyrotoxicosis (2a)

Levothyroxine should be used with caution in patients with severe thyrotoxicosis (2b)

Levothyroxine is not to be used in patients with severe tetany

Levothyroxine is not to be used in patients with tetany

If you notice any signs of hyperthyroidism or thyroid hormone deficiency, consult your doctor or pharmacist -

If you experience symptoms of hypothyroidism such as tiredness, agitation, irritability, clammy skin, slow heartbeat, fast heartbeat, feeling short of breath, shallow breathing, perspiration, perspiration sickness, or perspiration after using levothyroxine thyroid drugs,

Please note that the drug is not for use in women and is not expected to be use in men. It is not recommended for use in women and is not recommended for use in men only. Consult your doctor or pharmacist -

Levothyroxine is not expected to be used in women and is not expected to be used in men only. It is not recommended for use in women and is not used for treating hypothyroidism.

Levothyroxine is not to be used in patients with thyroid cancer, as it may increase the risk of developing multiple endocrine tumors (such as and ).

Levothyroxine must not be used in patients with hormone-sensitive cancers such as breast or endometrial cancer. Also, it must not be used in patients with hormone-receptor-positive breast cancer such as lumpectomy (an ovary removed and opened to gain a uterus) or.

Please refer to the specific drug for each person

For use as directed by your doctor, please read the instructions carefully

Levothyroxine must NOT be used in women who are or may potentially be pregnant. Levothyroxine passes into breast milk but is unlikely to harm an unborn baby. It must not be used in pregnancy.

Synthroid for Weight Management in Adults

• Synthroid is an oral medication that is commonly used to treat hypothyroidism. It contains T4 hormone, which is a synthetic form of the thyroid hormone thyroxine (T4). It works by replacing the thyroid hormone thyroxine (T4) that is normally produced by the thyroid gland. Synthroid comes in two forms, T4 and T3.
• Unlike many other medications that are primarily used to treat hypothyroidism, Synthroid is used to treat weight management in adults.
• Synthroid can be taken by adults who do not have hypothyroidism, but not if they are trying to lose weight. Weight management is a normal part of this process. It helps to relieve symptoms of weight loss, such as fatigue, weight gain, and bloating. This helps maintain a healthy weight.
• Synthroid can also help to slow the progression of hypothyroidism, which is a condition in which the thyroid gland does not produce enough thyroid hormone. Synthroid works by helping to restore the balance of thyroid hormones in the body. It is important to note that Synthroid can have some side effects in people taking the medication. It is important to speak with a healthcare provider before taking Synthroid, especially if you have certain medical conditions.
• The medication Synthroid can be taken by adults who do not have hypothyroidism.
• Taking Synthroid can cause a wide range of side effects in people taking the medication. It is important to talk with a healthcare provider about any side effects you experience. They may want to monitor you for these side effects, or they may want to discontinue Synthroid if you have any side effects. Some common side effects of taking Synthroid include headache, fatigue, nausea, and abdominal pain.
• People who have not been prescribed Synthroid may have other health problems, such as blood clotting disorder, which can result in a blood clotting disorder.

Symptoms of Hypothyroidism

Symptoms of hypothyroidism may include weight loss, fatigue, nausea, bloating, and swelling of the ankles or legs. These symptoms can be signs of hypothyroidism. The symptoms of hypothyroidism include:

• Abdominal pain
• Fatigue
• Weight gain
• Bloating
• Diarrhea
• Insomnia
• Insomnia that lasts more than 3 hours
• Abdominal cramping
• Abdominal bloating
• Nausea

Drug Interactions with Synthroid

Synthroid may interact with certain drugs, including:

• Certain drugs, including certain antidepressants
• Certain drugs, including certain blood pressure medications
• Certain supplements
• Certain medications, including certain vitamins and herbs
• Certain antibiotics
• Certain vitamins and herbs

Taking Synthroid

Taking Synthroid can affect how your body absorbs the medication. The effects of taking Synthroid can be affected by certain factors, including:

• The medication may cause a decrease in the amount of thyroid hormone, which is what makes the medication less effective. The medication will also affect how the body absorbs the medication.
• Taking Synthroid may also reduce the effectiveness of the medication, which makes it less effective.
• Taking Synthroid can also cause the body to release more thyroid hormones and decrease the amount of sodium and chloride in the blood. Synthroid will also affect how the body makes vitamins and other minerals.
• Taking Synthroid can also affect how your body uses your body. The body uses the medication to make its own absorption into your body more efficient. The body will also make more of the medication in the body than it would if it were not taking it.
• Taking Synthroid may also cause you to feel tired or have diarrhea, which can cause you to feel more weight loss.

Thyroid

Thyroid and the Brain

byNathan E. Williams, MD

A study published in the Journal of the American Academy of Neurology in 2009 showed that hypothyroidism, a condition in which the body lacks thyroid hormone, can lead to mental health issues in some patients. The study, which was led by Dr. Williams, was a collaboration between the University of Texas Health Science Center at Houston and the Baylor College of Medicine. The study involved a group of 10 healthy volunteers of varying ages. Each volunteer had a thyroid-stimulating hormone (TSH) level of about 300 pg/ml in their blood. The volunteers were given a standard dose of Synthroid (25 mcg/day) in a once-daily dose to help them maintain a normal thyroid hormone level and prevent symptoms of hypothyroidism. The researchers found that the study participants who were given Synthroid had a reduction in their risk of developing mental health problems compared to those who were given a placebo. Additionally, the study found that the study participants who received Synthroid had a significantly reduced risk of mental health problems compared to those who received a placebo. One of the results was that Synthroid had a significant improvement in symptoms of hypothyroidism, and the researchers concluded that the study was consistent with the findings in the Journal of the American Academy of Neurology. The study was published in the Journal of the American Academy of Neurology.

The study is the first to show that thyroid hormone can be a direct trigger for mental health issues. The research, which was funded by the National Institute on Aging, has also shown that patients with hypothyroidism often have a reduced level of thyroid hormone compared to patients who have normal thyroid hormone levels. The researchers noted that many patients with hypothyroidism also have low levels of free thyroid hormone. The researchers said that patients with hypothyroidism may have a lower incidence of mental health problems compared to those who have normal thyroid hormone levels.

The research was published in the American Journal of Psychiatry. The Journal of the American Academy of Neurology published its results in the Journal of the American Medical Association's journal of Neurosurgery.

The study was a collaboration between the University of Texas Health Science Center at Houston and Baylor College of Medicine. Dr. Williams, who led the research, is a board-certified neurologist and the University of Texas Health Science Center at Houston's Research Institute for the Study of Hypothyroidism. The study was led by Dr. David A. Burch, M. D., a professor of psychiatry, at the Houston College of Medicine. Burch was also the Medical Director of the Baylor College of Medicine, a division of Baylor University, where he served as Medical Director from 2003 to 2012. Williams is also a director of the Baylor College of Medicine's Institute for Brain Research, a division of Baylor University.

The study was supported by the National Institute of Aging (NIA), and the National Institute of Mental Health. The authors report no conflicts of interest in this publication.

Nth, 2014,,,This document is a summary of patient information. The statements, opinions and conclusions expressed in this publication are those of the authors and do not have the date of publication.The statements, opinions and conclusions expressed in this publication are not the responsibility of the authors and do not necessarily represent the official views of the American Academy of Neurology or the American Medical Association.

This publication includes data from the following publications:

• The Women's Health Initiative Study
• NCT006800982
• Spiriva and its Study of the Relationship between Hypothyroidism and Depression
• Spiriva's Depression Study

The Women's Health Initiative Study was a study of thyroid patients who had been diagnosed with hypothyroidism. The investigators recruited approximately 2,500 women and determined that they had hypothyroidism and were assigned to one of four groups, and a placebo group. The women in the hypothyroidism group received a normal dose of Synthroid (25 mcg/day) for 6 weeks. They were followed up in the 6-week postmenopausal phase, and their thyroid levels were measured again at 6 weeks. Synthroid levels were measured again at the 6-week follow-up.

During the 6-week postmenopausal phase, the investigators monitored thyroid levels in the women.

When it comes to treating hypothyroidism, the most commonly prescribed medications are levothyroxine (T4) and Synthroid (Euthyrox tablet). In many cases, you will need to consult with your healthcare provider for the right medication for you.

However, it is important to remember that not all medications are equal and that each can come with its own set of side effects. The different side effects of each medication can vary in severity and may have varying impacts on your health. So, it is crucial to have your healthcare provider’s guidance to determine the right medication for you.

The most commonly prescribed medications for hypothyroidism include levothyroxine (T4), Synthroid (Euthyrox), and Armour. Levothyroxine (T4) is an effective medication for treating the symptoms of hypothyroidism.

For a more detailed list of side effects, you can also read our.

Causes

Levothyroxine is the most commonly prescribed medication in hypothyroidism. In addition to levothyroxine (T4), Synthroid (Euthyrox), and levothyroxine, other medications are also used to treat hypothyroidism. There are various other medications that are prescribed to manage the symptoms of hypothyroidism, such as the following medications.

Levothyroxineis an effective medication for managing hypothyroidism. Levothyroxine is a synthetic form of the thyroid hormone thyroxine, and it helps regulate the thyroid hormone levels. It is available in both tablet and liquid forms, and it works by replacing the missing amount of the thyroid hormone.

SynthroidSynthroid is a synthetic form of the thyroid hormone T4 and is available in both tablet and liquid forms. It works by replacing the missing amount of the thyroid hormone.

The active ingredient of levothyroxine is levothyroxine (T4). Levothyroxine is a synthetic form of the thyroid hormone thyroxine.

The active ingredient of Synthroid is Synthroid. Synthroid is a synthetic form of the thyroid hormone T4.

The active ingredient of Armour is levothyroxine. Armour is a synthetic form of the thyroid hormone T3 and is available in both tablet and liquid forms.

Levothyroxine Dosage

The most common dosage of Levothyroxine for hypothyroidism is 5 mcg daily. Your healthcare provider will help determine the optimal dose and frequency for you based on your individual symptoms and response to treatment.