Birth Control And Hypothyroidism

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Is It Safe To Use Hypothyroidism Medication And Birth Control At The Same Time?

The endocrine system found in the human body plays an essential part in many functions that are executed in the body.

This system is responsible for the production and excretion of vital hormones into the blood circulatory system which, in turn, is delivered to cells to assist with many different functions, such as energy metabolism, cellular growth, cellular turnover, and more. The Thyroid Gland is found in the neck and is said to resemble a shape that is similar to that of a butterfly.

This Gland forms part of the endocrine system and secrets Thyroid hormones, including Thyroxine and Triiodothyronine. These hormones are responsible for metabolic functions in every single cell that is found in the human body.

Hypothyroidism is a condition in which the Thyroid gland does not produce enough hormones to support cellular metabolic functions throughout the body. There are many causes behind this condition, and a number of complications may develop if the condition is not treated promptly.

Treatment for hypothyroidism is relatively easy and also considered safe, but when it comes to the administration of Levothyroxine drugs, a patient needs to be wary of potential interactions that may occur with existing drugs they are taking.

Here, we will take a look at whether it is safe to take hypothyroidism medication and birth control medication at the same time, and what you can do to ensure you do not experience adverse interactions between these two types of drugs.

Treatment Protocols For Hypothyroidism

Hypothyroidism, including Hashimoto’s, can cause a patient to experience a number of unpleasant symptoms, which could interfere with their performance at work and even become a problem in their daily life. Symptoms such as poor concentration and memory problems, accompanied by fatigue and exhaustion1, can make it difficult for the patient to be productive in the workplace. Other conditions, such as weight gain and high blood pressure, can cause them to experience complications with their general wellbeing.

Obesity increases the patient’s risk of developing heart disease, diabetes, liver disease, kidney disease, osteoarthritis, depression, and sleep apnea2 – all of which have been associated with a possibility of early death.

Treatment for hypothyroidism is relatively simple, but can only be provided to a patient following an official diagnosis. A blood test is needed to assist a physician in determining the current levels of Thyroxine, a Thyroid hormone that is often referred to as T4, present in the patient’s blood circulatory system.

Most blood tests will also request a reading of the Thyroid Stimulating Hormone levels present in the patient’s blood sample. This will help the physician determine the most appropriate dosage of Thyroid Hormone Replacement drugs to provide the patient.

The most common form of treatment administered to a patient diagnosed with hypothyroidism is a drug called Levothyroxine3. This is a synthetic version of the Thyroid hormone Thyroxine and helps to increase the level of T4 hormones in the blood circulatory system of the patient.

Many patients find that the initial dosage of Levothyroxine provided to them is not completely effective, but slight adjustments in the dosage during the starting period of Thyroid Hormone Replacement therapy can help the physician and patient find the right dose together.

Most Common Birth Control Drugs

Numerous options are available to provide a method of birth control to both men and women. Amongst women, birth control pills often referred to as oral contraceptives, is one of the most common methods used to prevent a woman from becoming pregnant following sexual intercourse.

Birth control pills utilize a preparation of hormones to help prevent pregnancy. These pills can either contain progestin or a combination of both progestin and estrogen hormones. The idea is to prevent the brain from releasing follicle stimulating hormones, also known as FSH, and luteinizing hormone, or LH – both hormones being produced by the pituitary gland situated at the back of the brain.

These hormones are essential for preparing the eggs for fertilization – by reducing the release of these hormones, the chance of becoming pregnant becomes significantly lower.

There are three different main types of birth control and oral contraceptive drugs that a woman can opt for when she wishes to utilize these drugs to help prevent pregnancy during sexual intercourse. These three different types include:

  • Monophasic oral contraceptives
  • Biphasic oral contraceptives
  • Triphasic oral contraceptives

Possible Interactions Between Levothyroxine And Birth Control Pills

Many pharmaceutical drugs are known to interact with each other, making it essential for patients to consider every single drug they are taking and to determine whether any of these may have interactions with each other. When it comes to the usage of Levothyroxine for the increase of Thyroxine hormones in the body and the use of birth control pills simultaneously, patients need to be wary of the fact that specific interactions can make the Levothyroxine medication less effective.

When a patient takes birth control pills that contain estrogen hormones, the oral contraceptives can lead to a higher level of thyroxine-binding globulins, also known as TBG, to be present in the body. Additionally, the estrogen causes these globulins to circulate in the blood circulatory system for a more extended period of time.

Thyroxine-binding globulins bind to up to 99% of the Thyroxine hormones produced by the Thyroid, which means only around 1% of these hormones remain free in the body to be utilized by cells to support their metabolic functions.

The use of estrogen in birth control pills causes a higher uptake of Thyroxine hormones, due to an increased level and existence time of the thyroxine-binding globulin in the patient’s body. This means that a patient also taking Levothyroxine may notice that symptoms associated with Hypothyroidism start to return when they take birth control pills, due to a lower amount of Thyroxine hormones being “free” and available for the body to utilize.

In turn, this leads to the need for a higher dosage of Levothyroxine by the patient once they start taking birth control pills. Luckily, increasing the dosage of Thyroid Hormone Replacement drugs should not be a significant problem and, in most cases, should not lead to the development of unpleasant side-effects.

As a safety precaution, patients are advised to opt for regular checkups with their doctor to ensure the efficiency of their Levothyroxine medication is not adversely affected by the use of birth control medications. When follow-up blood tests are requested, the physician should choose to test for Thyroid Stimulating Hormone readings instead of Thyroxine, as this will give a better indication of whether the Levothyroxine dosage needs to be adjusted in the patient who is diagnosed with Hypothyroidism and using birth control pills.

It should be noted that, even though birth control pills can interact with Levothyroxine and cause the level of Thyroxine hormones in the patient’s body to become reduced, the interaction does not work both ways.

The use of Levothyroxine will not have an effect on the efficiency of the birth control pills that the patient is taking.

How To Safely Use These Two Medications At The Same Time

Even though the use of birth control pills could make Levothyroxine drugs less effective, which calls for an increase in the dosage, it should be noted that some methods can be used to use these pharmaceutical drugs together safely.

Firstly, it is highly recommended that the patient is monitored by a physician with prior experience in dealing with clients who are in need of this particular combination – birth control pills and Levothyroxine. The physician should also perform frequent checkups to ensure the interaction between the two drugs is not causing significant interference with the patient’s existing Thyroid-related health issues.

Additionally, a patient who is taking both of these medications should consider adjusting the way they take their medication. When taking both birth control pills and Thyroid Hormone Replacement drugs at the same time causes a significant increase in the risk of experiencing interactions between the drugs. For this reason, the patient should instead consider splitting the dosages to different times of the day.

The patient can still take both the birth control pills and the Levothyroxine medication during a single day, but it is essential that these drugs are not taken at the same time – instead, take one in the morning and the other one at lunchtime or perhaps before going to bed. Talk with an experienced physician may provide the patient with an idea of how to appropriately time their dosage of each drug to ensure maximum efficiency, while also reducing the risk for interactions.

Considering Alternative Birth Control Methods

Even though birth control pills containing certain hormones are considered to be the most popular method of contraception, patients who find that the use of these pills causes too much of an interference with their Levothyroxine medication should be aware of alternative options that can be used for birth control.

Birth control pills are not the only options that can be used to prevent pregnancy during sexual intercourse – there are many other options that a patient may opt for if they fear the possible interaction of birth control pills with their current Thyroid Hormone Replacement therapy plan.

While not considered as effective of an approach as birth control pills, the use of condoms can provide some level of protection to assist with reducing a woman’s risk of becoming pregnant when she participates in sexual intercourse with a man.

There are condoms available for both men and woman that can help to prevent sperm from entering the woman’s body and causing her to become pregnant. The “withdrawal” or “pull-out” method is another solution but needs careful consideration.

Other options that can be utilized include a sponge or a diaphragm. Cervical caps also offer a safe and effective birth control option without the need to use any type of hormones; thus avoiding the potential interaction of birth control methods that utilize hormones and the use of Levothyroxine drugs for the treatment of Hypothyroidism.

In cases where a woman is certain that she would not want to have any more children in the future, sterilization poses as an effective method to provide a method of contraception without having to rely on any type of synthetic hormones.


Hypothyroidism is a very common condition, especially amongst women, and needs to be treated promptly to avoid further complications and the development of certain health ailments. Treatment is relatively simple but finding the perfect dosage for the patient can take some time.

When a patient is taking Levothyroxine to assist with the treatment of Hypothyroidism, it is important to consider the possibility of the medication interacting with birth control pills.

In this post, we provided an overview of possible interactions between hypothyroidism medication and birth control pills and provided some tips to help you stay safe when you are taking both of these drugs.


1 Hypothyroidism: Symptoms. PubMed Health.

2 X. Pi-Sunyer. The Medical Risks of Obesity. HHS Public Access. 1 November 2009.

3 Multiple Authors. Treatment for primary hypothyroidism: current approaches and future possibilities. Dovepress. 22 December 2011.

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