Levothyroxine Side Effects

Before we discuss Levothyroxine side effects you need to know what the drug is manufactured for. Technically, the drug is designed to replace a hormone in the body that is naturally produced by your thyroid gland. Your body needs this hormone to keep your metabolism in check. Doctors prescribe the drug when the thyroid gland isn’t producing as much of the hormone as the body needs. As a result, your body eventually experiences drastic drops in energy levels throughout the day.


This condition is also known as hypothyroidism. The drug is also used to counteract a range of other thyroid related medical issues like thyroid nodules and goiters. Of course, like in the case with most types of medication, Levothyroxine also comes with its fair share of side effects. The drug is relatively harmless but some patients have ended up with nasty side effects after ingesting the drug. The following are some of them –


Allergic Reactions

Allergic reactions to the drug are rare. However people who are unfortunate enough to suffer from them usually break out in hives or rashes after taking the drug. Some parts of their body might start to swell as well especially the skin around the mouth and neck area. Other signs include troubled breathing or wheezing. 

Extreme cases include dizziness, itchiness and sudden hoarseness. If you or anyone you know exhibits these signs seek medical attention immediately.


Gastrointestinal Effects

Medication overdose rarely bores well for those at the receiving end of it. A Levothyroxine overdose is no better. For example, a person may experience extreme weightless despite having a hearty appetite. A patient who happens to overdose might also keep throwing up at intervals or experience painful stomach cramps.


Neurological Effects

The drug has been known to cause hyperactivity and muscular weakness in some cases. Don’t be surprised if you start feeling irritable and cranky after the drug has taken effect.

Medical experts also advise against taking the drug during a heart attack and for good reason. An overdose might cause the heart to palpitate at an alarming rate or result in cardiac arrest. Extreme cases have also recorded heart failure. You might also start to sweat profusely or feel feverish.

Patients might also feel their bones becoming more brittle especially if they have been taking the drug for a long time. This is also why such patients are prone to fractures.

Doctors also advise against taking the drug with some other forms of medication especially those that are manufactured for weight loss. Such combinations can prove to be fatal. In fact, taking additional medication along with the drug can also prevent the body from absorbing it thereby rendering it useless. Make sure that you inform your doctor about any conditions you might have like asthma, heart problems, high cholesterol, diabetes or other related issues before you get on the drug.  Also make sure that you keep the discussed symptoms in mind in case you do happen to suffer from any Levothyroxine side effects.

Levothyroxine Dosage

If you happen to suffer from hypothyroidism, chances are that you were prescribed a certain Levothyroxine dosage. Levothyroxine is a drug that is often prescribed for patients who suffer from thyroid related issues. If you or someone you know happens to have an inactive thyroid, chances are that they have been put on the drug. Many specialists also recommend Levothyroxine off-label in order to treat patients who might not suffer from the condition especially those who suffer from depression.



There is no standard dosage for the drug simply because the patients for whom it is prescribed for suffer from varying levels of hypothyroidism or some other thyroid related conditions. Dosages also vary according to how a patient’s body reacts to the drug and is thereby administered accordingly. In general, a Levothyroxine dosage usually does not exceed more than 200 mcg per day.


Adult Dosage for Hypothyroidism

The medication itself is usually taken either as a pill or a gel once every morning. The initial dose for adults ranges from 12.5 to 50mcg per day. Intake might be adjusted or increased from 12.5 to 2.5 mcg per every two to four weeks.  Whatever dosage the doctor prescribes make sure that you take it at the same time every day. This will help your body regulate the drug throughout your bloodstream more effectively.

Your dosage will also depend on medical tests. For example, your health care provider will adjust your Levothyroxine dosage according to your blood tests. This is also why you must ensure that you inform your health care provider if you happen to miss any of the dosages. In such cases, the medical specialist will need to re-adjust the level of the dose.

Taking the medication on a full stomach is not advisable. If you have already had breakfast, make sure that you wait 40 to 60 minutes before taking the prescribed dose. In fact, in order to maximize the effects of Levothyroxine you can take it –

  • With water
  • An hour before taking any other medication, vitamin or supplement
  • Two hours before iron or calcium intake.


It is not advisable to administer large doses of Levothyroxine in patients who are prone to concomitant heart disease. However, a smaller dosage is no cause for concern. Doctors usually double up the dosage if a patient happens to miss one. In other words, the dose is increased as much as your body needs to catch up.

The medication is crushed or mixed with water when it comes to young children. However, when it comes to infants the dosage is as low as 5mcg/dL.

Also make sure that you do your research before taking any other forms of medication along with the drug. For example, there is certain nonprescription flu medication that should not be taken with Levothyroxine. The same is the case with some over the counter drugs, especially those that contain iodine or the thyroid hormone. These have the propensity to compromise your Levothyroxine dosage and should be given a wide berth.

Levothyroxine Sodium

Levothyroxine sodium or Synthroid as it is commonly known is a man made drug that is used for combating thyroid hormonal deficiency or over production. Basically, it is a synthetic form of the thyroid hormone, T4 (thyroxin). In general, the hormone itself is produced and released by the thyroid gland which is use to increase your body cells’ metabolism.


The tablets (both the generic and branded versions) may differ according to –


      √ The absorption rate of levothyroxine in the body

      √How much levothyroxine they contain

      √The rate of distribution of levothyroxine in the body.


Is it Suitable for you?

It is important to determine whether thyroid medication will suit you before you take it. The same is the case with Levothyroxine sodium. The drug isn’t suited for everyone. Use the drug with care even if your body does not react to it adversely. This is also why doctors ask for a thyroid patient’s medical history before prescribing the drug.



If you know that you are allergic to the drug make sure that you inform your doctor or pharmacist about it. The drug may contain inactive elements that can make your body reject it. It is also best that you inform your doctor of your medical history in full detail especially if your body is susceptible for producing more thyroxin than is necessary (thyrotoxicosis) or if you suffer from heart disease, decreased adrenaline gland function, diabetes or even high blood pressure.


Also make sure that you inform the medical specialist about any products that you are currently using like herbal products and nonprescription as well as prescription drugs. This is important especially if you have to undergo surgery. Based on the analysis, the prescriber might not recommend levothyroxine sodium at all if –


      √You have a history of allergic reactions to any of the ingredients that are present in

         the drug.

      √You are more than 50 years old.

      √Are diabetic.

      √Have adrenal problems or are susceptible to developing them.

      √ Recently suffered from a heart attack.

      √Have high blood pressure.

      √Suffer from thyrotoxicosis


In order to gauge whether you will be suitable for the drug, the medical specialist might also perform some medical tests. There have also been cases in which patients have developed intolerance to the drug later on even if they have been taking it for a long time. If you find yourself or anyone you know in such a situation it is integral that you contact the concerned prescribers at once.


If you do find yourself capable of taking the drug remember that it also comes with its fair share of side effects. Therefore it is best that you skip operating any heavy machinery or driving to work if you are prescribed the drug. If you absolutely have to, judge whether your medicated state allows you to perform the mentioned tasks.


The effect of the drug also varies in accordance to varying stages of pregnancy. For example, a doctor might prescribe levothyroxine sodium to a pregnant woman only if he thinks she needs it.

Levothyroxine weight loss

Levothyroxine weight loss is a trending topic in body building circles. The drug itself is mainly used to counteract an autoimmune disorder, thyroditis. The condition occurs when your immune system starts attacking the thyroid thereby rendering it unable to produce hormones. The state is also commonly known as hypothyroidism and can result from a damaged pituitary gland, atrophy, cancer, hypothalamus, and through radiation caused by some other forms of medication.


What does it have to do with Weight Loss?


Since the thyroid hormone, thyroxine, is responsible for increasing the metabolism of your body cells it is not surprising why many also use it for shedding a few pounds. In order to burn off calories and aid in protein synthesis individuals have been known to take more of the drug than is normally prescribed for them.


Professional body builders are known to take the drug especially during the cutting phase. This phase involves shedding off body fat especially if they want to preserve their muscle mass while working out.


Weight Loss Diet with Levothyroxine


People with thyroid conditions usually suffer from low metabolism. This means that your body might not be able to process as much sugar as it used to. Such a state can cause your glucose and insulin levels to spike at drastic levels. This cannot bode well in the long run especially if you are using Levothyroxine as a weight loss remedy. Using the glycemic index and staying on a diet of complex carbs will help you lose weight on Levothyroxine. Foods contained in these diets will not affect your glucose levels as much.


The same level of caution must be observed with your food portions. While it is true that you will lose more weight as you lose more calories, make sure that you never decrease your intake to less than 12,000 to 15,000 calories a day. Any less and your metabolism will drop to alarming levels.




Levothyroxine is actually considered to be unsuitable for combating weight loss and obesity. Medical experts also advise against taking the drug with any weight loss medication or as part of a weight loss diet. Failure to comply usually results in overdose or allergic reactions.


This is also why the drug is prescribed for patients with hypothyroidism according to their body weight and age. For example, an adult who is less than fifty years of age and weighs150 poundsmight be prescribed a 100 to 125mcg daily dose of Synthroid.


If you are on a weight loss program and suffer from hypothyroidism make sure that you never take the drug on a full stomach. The diet that you follow must not contain anything that might prevent the drug from absorbing in your body either. For example, vitamin supplements that contain iron or calcium can make it impossible for the drug to be fully absorbed. Wait two to four hours to eat anything that might hinder the absorption process especially when it comes to Levothyroxine weight loss.

Side Effects of Levothyroxine

The side effects of Levothyroxine differ from individual to individual. That does not mean that you stop taking the medication entirely especially if you happen to suffer from abnormal thyroid function like hypothyroidism. However, some people still make the mistake of skipping on their meds just because they are afraid of possible side effects.


The Thyroid

In general, the thyroid is a small pear shaped gland that is responsible for secreting hormones which in turn regulate your metabolism. The hormones are also responsible for regulating your body temperature, heart rate and energy levels.

Some of the very common excuses most patients give are –

  • Why should I take more when I don’t feel any better with it?
  • Prescription medication scares me.
  • My health was perfectly fine before I started taking my meds. The side effects are not making it worth my while.
  • Natural remedies are safer.
  • I forget when I am supposed to take it every day. It’s a bother having to double my dosage just to keep up.
  • It makes me feel worse.


Levothyroxine is just one of the drugs that are used to combat thyroid related medical issues. Other like thyroid dysfunctions that warrant specific medication are –


        √  Anatomical issues – Goiter



This condition indicates an over active thyroid. It can be caused due to an overproduction of the thyroid hormone by the thyroid gland or by their excessive intake of drugs that trigger overproduction.



This condition indicates an under active thyroid. Like the name implies, it happens when the thyroid gland does not secrete as much hormones as are needed to keep the body’s metabolism in check. The effects are felt throughout the whole body due to which it eventually stops to function as efficiently. The condition usually occurs in adults but children are also known to develop it on some occasions. For example, congenital hypothyroidism is a thyroid related condition that is present from birth.


 A more serious form of the condition is Myxedema or advanced hypothyroidism. The condition is an unfortunate product in patients with long term undiagnosed hypothyroidism. According to research, women are more likely to develop the condition as compared to men.


All of these are counteracted with conventional thyroid medication. However the same drugs also happen to involve radioactive iodine treatment, synthetic hormones as well as others. Needless to say, such treatments do have a propensity to end up in serious side effects which means that patients have to be monitored on a regular basis.


The symptoms related to thyroid dysfunctions themselves are almost negligee and might also imitate other diseases. The side effects of the medications that are used to treat them, however, can be more serious. This is also why it is important for patients to determine whether their poor health is due to thyroid malfunction or something else. The side effects of Levothyroxine as well as other thyroid medication can become fatal if you are not careful on how you use them.