Levothyroxine versus thyroxine
2026-02-07Are you wondering which thyroid medication is right for you?
Levothyroxine and thyroxine are two common medications used to treat hypothyroidism.
Levothyroxine is the synthetic form of thyroxine, a hormone produced by the thyroid gland.
Consult your doctor to determine the best option for your thyroid health.
Main differences between Levothyroxine and thyroxine
Levothyroxine: Levothyroxine is a synthetic form of the thyroid hormone thyroxine, also known as T4. It is the most commonly prescribed medication for hypothyroidism and other thyroid-related conditions.
Thyroxine: Thyroxine, also known as T4, is the natural hormone produced by the thyroid gland. It plays a crucial role in regulating metabolism, growth, and energy levels in the body.
Key differences: The main difference between Levothyroxine and thyroxine is that Levothyroxine is a synthetic version of the hormone, while thyroxine is the natural hormone produced by the body. Levothyroxine is used as a replacement therapy for individuals with low thyroid hormone levels, while thyroxine is essential for the body's normal functioning.
Side effects of Levothyroxine and thyroxine
When taking Levothyroxine or thyroxine, it is important to be aware of the potential side effects that may occur. Some common side effects of both medications include:
- Headache
- Nervousness or anxiety
- Tremors
- Weight loss
- Irregular heartbeat
- Excessive sweating
In some cases, more serious side effects may occur, such as:
- Chest pain
- Rapid or irregular heartbeat
- Shortness of breath
- Allergic reactions
- Changes in appetite
If you experience any of these serious side effects, it is important to seek medical attention immediately. Additionally, if you have any concerns about the side effects of Levothyroxine or thyroxine, be sure to discuss them with your healthcare provider.
Side effects of Levothyroxine and thyroxine
Like any medication, Levothyroxine and thyroxine may cause side effects. Common side effects may include:
- Weight changes: Some individuals may experience weight gain or weight loss while taking Levothyroxine or thyroxine.
- Heart palpitations: In some cases, these medications can cause an irregular heartbeat or palpitations.
- Nervousness: Some people may feel jittery or nervous as a side effect of Levothyroxine or thyroxine.
- Headaches: Headaches may occur as a side effect of these medications.
- Insomnia: Some individuals may have difficulty sleeping while taking Levothyroxine or thyroxine.
If you experience any severe or persistent side effects, it is important to contact your healthcare provider immediately.
Proper dosage of Levothyroxine and thyroxine
It is essential to follow your healthcare provider's instructions regarding the proper dosage of Levothyroxine and thyroxine. The dosage will vary depending on the individual's age, weight, medical condition, and other factors.
Typically, the initial dose of Levothyroxine for adults with hypothyroidism is 1.6 mcg per kg body weight per day. This dosage may be adjusted based on regular monitoring of thyroid hormone levels.
For children and infants, the dosage of Levothyroxine is based on their weight and age. It is crucial to follow the prescribed dosage and never adjust it without consulting a healthcare professional.
Thyroxine dosage is also individualized and depends on the specific needs of the patient. Your healthcare provider will determine the appropriate dosage of thyroxine based on your thyroid hormone levels and overall health.
It is vital to take Levothyroxine and thyroxine exactly as prescribed, preferably on an empty stomach, at least 30 minutes before eating. Avoid taking these medications with certain foods, supplements, or other medications that may interfere with their absorption.
Interactions with other medications
Levothyroxine and thyroxine can interact with other medications, leading to potential complications or reduced effectiveness of treatment. It is important to inform your healthcare provider about all the medications you are taking before starting Levothyroxine or thyroxine therapy.
| Medication | Interaction |
|---|---|
| Antacids | Can decrease the absorption of Levothyroxine or thyroxine when taken together. It is recommended to take them at least 4 hours apart. |
| Warfarin | Levothyroxine can alter the effects of warfarin, leading to changes in blood clotting time. Close monitoring is necessary. |
| Cholestyramine | Can bind to Levothyroxine or thyroxine in the intestine, reducing its absorption. They should be taken at least 4 hours apart. |
| Diabetes medications | Levothyroxine may increase the effects of diabetes medications, requiring adjustment of the dosage. |
| Estrogen-containing hormonal therapy | Estrogens can increase the levels of thyroid-binding proteins, affecting the availability of Levothyroxine or thyroxine in the body. |
Always consult with your healthcare provider before making any changes in your medication regimen when taking Levothyroxine or thyroxine.