Levothyroxine Uses, Dosage and Side Effects

Levothyroxine Uses

Levothyroxine (or levothyroxine sodium) is a thyroid medication used to treat hypothyroidism (low thyroid hormone levels). It is also used to prevent goiter (when the thyroid gland enlarges) and the resulting health problems the condition can cause. Patients are also often prescribed this medication for weight gain, and/or fatigue.


Levothyroxine Uses - Doctor checking thyroid glandes of a patient

Before continuing to speak about this medication, let’s first have a quick understanding about thyroids.

What is Thyroid And How Does it Affect Your Health?

Thyroid is a specialized tissue located on the front of each of your lungs. It’s one of the most important glands in your body, because it controls the metabolism and body weight. There are two types of thyroid, the follicular and the parathyroid. Both organs work together to regulate hormone levels throughout your body.

Thyroid is a small, butterfly-shaped gland located in the neck just below the Adam’s apple. As part of the endocrine system, the thyroid produces and releases hormones that regulate body temperature, release energy from food intake and convert stored food into usable fuel for everyday functions. These hormones also control how fast or slow various organs function.

There are two types of thyroid hormones, T3 and T4, which are called thyroxine. The T3 hormone increases the cells’ energy use, while T4 decreases it.

Thyroid hormone is responsible for regulating the metabolic rate of the body. If there is a lack in thyroid hormone, it can lead to health issues like weight gain, fatigue, constipation, water retention and depression.

Now we have learned about the thyroid’s functions and importance, let’s continue our exploration about Levothyroxine uses, dosage and side effects.

Levothyroxine Pronunciation

The word Levothyroxine is simply pronounced as follows: leh·vuh·thai·rok·seen.

Levothyroxine Ingredients 

The following are the general ingredients of the Levothyroxine sodium tablet:

  1. Colloidal silicon dioxide
  2. Magnesium stearate
  3. Microcrystalline cellulose
  4. Lactose
  5. Sodium starch glycolate
  6. Acacia
  7. Corn starch

Levothyroxine Sodium Treatment Medication Tablet

Levothyroxine Dosage

Levothyroxine is an oral medication and can be taken with or without food. It comes in two forms, a tablet and a liquid. The liquid form of the medication can be taken as a solution or as a shot.

In nearly all cases, it is prescribed as a one-time dose for patients who have been on some other form of thyroxine medication for at least three months.

In order to decide which form of the medication might be best for you, consult with your doctor about their preference.

Levothyroxine Side Effects

Some people experience side effects when they take this medication, the severity and number of side effects differs from one person to another.

Top 10 Levothyroxine Side Effects:

  1. Abdominal pain
  2. Upset stomach
  3. Diarrhea
  4. Change in appetite
  5. Headache and mood swings
  6. Fatigue
  7. Rapid weight gain or weight loss
  8. Nausea
  9. Rash
  10. Vomiting

Levothyroxine Side Effects of Medication - Abdominal Pain, Fatigue and Headache

Levothyroxine Overdose

Levothyroxine overdose is a potentially fatal adverse drug reaction of a thyroid hormone medication. It occurs when the amount of the medication in the blood exceeds the therapeutic dose range.

Symptoms can include increased heart rate, increased blood pressure, allergic reactions, and dangerously high body temperature.

A dose of levothyroxine that is greater than 150 mcg can cause symptoms such as shortness of breath, chest pain, loss of consciousness, seizures and sometimes may lead to liver damage.

If you suspect you are experiencing these symptoms after taking this medication, contact your doctor immediately!

Levothyroxine vs Synthroid

Synthroid is the brand name for levothyroxine and was the first brand of the drug to be introduced. The main difference between Levothyroxine and Synthroid is that Levothyroxine can be taken as a pill, whereas Synthroid has to be injected.

Synthroid is a synthetic form of levothyroxine medication that’s available for patients who can’t tolerate levothyroxine.

Levothyroxine vs Euthyrox

Euthyrox is one of two brands of synthetic thyroid hormone, which is prescribed for managing the symptoms of low thyroid function in adults and children. Euthyrox is similar to Levothyroxine uses of the medication because it too increases thyroid hormone levels. However, Euthyrox does so without stimulating the heart or increasing blood pressure.

Levothyroxine for Weight Loss

Levothyroxine is not used to treat obesity, so it does not cause weight loss. However, some patients may see a reduction in appetite due to the side effects of Levothroid. If you need to lose a lot of weight, you should discuss with your doctor about the risks and benefits of these medications. The use of thyroid medication as a weight loss aid is controversial and not considered safe. In rare conditions, these drugs may lead to heart attacks or seizures!

Levothyroxine in Pregnancy

For some women, the doctor may advise to take levothyroxine (T4) medication during pregnancy with caution, however, Levothyroxine uses during pregnancy is controversial. To learn more about the benefits and risks of this medication during pregnancy, speak with a doctor.

Mother with baby at hospital

Levothyroxine and Nursing

Levothyroxine may not be recommended for women who are breastfeeding, however, it is generally safe due to the low levels of the medication in the breast milk. Please consult your doctor if you are nursing before taking this medication.

Levothyroxine for Dogs

Similar to the medical condition in humans, Levothyroxine for Dogs is a medication prescribed to control hypothyroidism in dogs. The treatment usually begins with the use of a low dosage and increases if necessary. The dosage will often be adjusted up or down depending on whether the dog’s thyroid gland enlarges, becomes more responsive to the medication, or produces too much hormone.

Levothyroxine for Dogs - Veterinarian Examining Thyroid of a Sick Dog

Levothyroxine is a very specific type of medication that can help dogs with thyroid problems, therefore, it is important for your pet to take this medication as prescribed by your veterinarian only and also make sure you buy the right dosage for your dog.


Levothyroxine is a medication that has a lot of uses and side effects. It can be prescribed to treat hypothyroidism, hyperthyroidism, and as a hormone replacement therapy. The medication can be used to treat the hypothyroidism in dogs too.

With this medication, your doctor will administer your thyroid hormone dosage. It can be taken by mouth or through an IV. The prescribed dose depends on the severity of the condition, the type of treatment, and other factors. Your doctor may also prescribe it to treat other conditions not related to thyroid health.

Levothyroxine uses on a regular basis can result in some unwanted effects such as nervousness, anxiety, depression, weight gain or loss and headache.

You are always advised to consult your doctor or vet and not to take or give any medication on your own.

Leave a Reply

Your email address will not be published. Required fields are marked *