Thyroid hormone replacement with a prescription thyroid drug is the standard treatment for hypothyroidism (low thyroid hormones) caused by an underactive thyroid gland, surgically removed gland, or congenitally damaged or missing gland. Autoimmune Hashimoto’s disease is the most common cause of hypothyroidism.
The goals of treatment include:
- Normalizing thyroid hormone levels, specifically, thyroxine (T4) and thyroid-stimulating hormone (TSH) levels
- Eliminating symptoms of hypothyroidism, like constipation, fatigue, and cold intolerance
- Halting and reversing any effects that hypothyroidism may be having on various organ systems (for example, elevated cholesterol levels)
- Reducing the size of a goiter, if present, as is sometimes the case with Hashimoto’s disease
Levothyroxine (T4)
Hypothyroidism is treated with prescription oral thyroid hormone preparation (usually levothyroxine, a T4 preparation). The ideal dosage is sufficient enough to restore normal thyroid hormone levels without producing toxicity from too much thyroid hormone.
Formulations
There are different formulations of T4 made by different manufacturers. While all FDA-approved formulations are judged to be suitable, most experts recommend sticking to the same formulation, since the dosage equivalents may vary somewhat among different preparations.
Dosing
For young, healthy people, healthcare providers will generally begin with what is estimated to be a “full replacement dose” of T4 (that is, a dose that is supposed to completely restore thyroid function to normal). The full replacement dose is estimated according to body weight and, for most people, is between 50 and 200 micrograms (mcg) per day.
In the United States, levothyroxine is available as generic levothyroxine, as well as Synthroid, Levothroid, and Levoxyl brand name tablets. Tirosint is a liquid gel cap form of levothyroxine that has been on the market since 2011.
For older people or people who have coronary artery disease, thyroid replacement therapy is usually started gradually, beginning with 25 to 50 mcg daily and increasing over time.
Administration
You should take T4 on an empty stomach to prevent the absorption of the medication from being erratic. Healthcare providers usually recommend taking the medication first thing in the morning, then waiting at least an hour to eat breakfast or drink coffee. Taking the medication at bedtime, several hours after the last meal, also appears to work and can be a more convenient approach for some people.
Begin with a dose between 50 and 200 micrograms (mcg) per day
Begins with a full replacement dose
Begin with a dose between 25 and 50 micrograms (mcg) per day
Dose begins low and gradually gets increased
Monitoring
TSH levels are monitored to help optimize the dose of T4. TSH stimulates the thyroid gland to make thyroid hormones. It is produced by the pituitary gland, and the body often adjusts the level of TSH in response to thyroid hormone levels.
So when thyroid hormone levels are low (as in hypothyroidism), the pituitary gland responds by increasing TSH levels. When hypothyroidism is adequately treated, TSH levels typically drop back down into the normal range. So, a mainstay in determining the best dose of T4 is measuring TSH levels.
If TSH levels remain above the target range, the dose of T4 is increased by about 12 to 25 mcg per day, and TSH levels are tested again after six more weeks. This process is continued until the TSH level reaches the desired range and symptoms are resolved.
How the Thyroid Gland Works
While symptoms of hypothyroidism usually begin to resolve within two weeks of initiating treatment, it takes about six weeks for TSH levels to stabilize. That is why TSH levels are generally measured six weeks after treatment has begun.
Once the optimal dose of T4 is settled upon, TSH levels are measured every year or so thereafter, to make sure the treatment remains optimized.
Liothyronine (T3)
While the standard approach to treating hypothyroidism (T4 replacement) works for most people, some people continue to experience symptoms.
Some practitioners may consider liothyronine (T3) as an add-on treatment for select individuals, though this is a matter of debate.
According to a 2016 study published in the Journal of Clinical Endocrinology and Metabolism, about 15% of people in the United States with hypothyroidism continue to have symptoms despite being treated for the disease.
The Controversy
T4 is the major circulating thyroid hormone, but it is not the active form of the hormone. T4 is converted to T3 in the tissues as needed. And T3 is the thyroid hormone that does all the work. T4 is merely a prohormone—a repository of potential T3 and a way of making sure that enough T3 can be created on a minute-to-minute basis as needed.
When you take T4 and not T3, the effects rely on your tissues to convert just the right amount of T4 to T3 at just the right place and at just the right time.
There is emerging evidence suggesting that some people with hypothyroidism might not have an efficient conversion of T4 to T3. When this is the case, despite the fact that T4 levels may be normal, T3 levels may be low, especially in the tissues, where T3 actually does its work.
Why T4 to T3 conversion may be abnormal in some people is, at this point, largely speculation—although at least one group of patients has been identified with a genetic variant (in the diodinase 2 gene) that reduces the conversion of T4 to T3.
Liothyronine is a synthetic form of T3, and it is available in a manufactured form as the brand Cytomel, and also as generic liothyronine. T3 can also be compounded.
It appears that healthcare providers should be treating at least some people (albeit, a small group, most likely) who have hypothyroidism with both T4 and T3.
Calculation of appropriate doses of T3 is trickier than appropriately dosing T4. T4 is inactive, so if you take too much there is no immediate direct tissue effect. T3 is a different story, though, as it is the active thyroid hormone. So if you take too much T3, you can experience hyperthyroid effects directly—a risk, for instance, to people with cardiac disease.
When adding T3 to T4 during thyroid replacement therapy, most experts recommend administering a ratio of T4:T3 —between 13:1 to 16:1, which is the natural ratio of people without thyroid disease.
If you’re taking combined T4/T3 therapy, your practitioner will usually check a TSH level six weeks after you begin treatment. T3 levels are not generally checked because currently available T3 formulations lead to wide fluctuations in T3 blood levels throughout the day.
Desiccated Thyroid Extract
Desiccated thyroid extract contains both thyroxine (T4) and triiododothyronine (T3), and is derived from the thyroid glands of pigs.
Several brands of desiccated thyroid are available by prescription in the United States and in some other countries, including Nature thyroid, WP Thyroid, Armour Thyroid, a generic NP Thyroid (made by manufacturer Acella), and a Canadian natural thyroid from manufacturer Erfa.
For Infants
In an infant diagnosed with congenital hypothyroidism, the goals of treatment are to restore thyroid levels to normal as quickly and safely as possible. The quicker the thyroid levels are normalized, the better the cognitive and motor skills development of the infant.
Important Note
While desiccated thyroid extract is available as a prescription, it’s rarely recommended by healthcare providers anymore, as there is no scientific evidence it has any benefits over synthetic T4.
Levothyroxine is the treatment of choice for congenital hypothyroidism.
Often, a liquid form of levothyroxine is given to infants. It’s important to not mix the levothyroxine with soy infant formula or any calcium or iron-fortified preparations. Soy, calcium, and iron can all reduce the infant’s ability to absorb the medication properly.
If levothyroxine tablets are given to an infant, parents should crush the levothyroxine tablet and mix it with breast milk, formula, or water that’s fed to the baby.
Children being treated for congenital hypothyroidism are evaluated on a regular schedule, often every several months for at least the first three years of life.
Permanent or lifelong congenital hypothyroidism can be established by imaging and ultrasound studies showing that the thyroid is missing or ectopic, or a defect in the ability to synthesize and/or secrete thyroid hormone is confirmed.
According to the European Society for Paediatric Endocrinology, in congenital hypothyroidism, serum T4 or free T4 and TSH blood tests should be performed at the following times:
If permanent hypothyroidism has not been established, levothyroxine treatment may be discontinued for a month at age 3, and the child retested. If levels remain normal, transient hypothyroidism is the presumed diagnosis. If levels become abnormal, permanent hypothyroidism is diagnosed.
Children with transient congenital hypothyroidism who are taken off medication should have periodic thyroid evaluation and retesting, as these children face an increased risk of developing a thyroid problem throughout their lives.
During Pregnancy
Having sufficient thyroid hormone throughout pregnancy is necessary in order to protect your pregnancy and the health of your baby. The drug of choice during pregnancy is T4 since T3 does not cross the placenta and T4 is very important for fetal brain development.
Before Pregnancy
According to guidelines from American Thyroid Association, the dosage of thyroid hormone (levothyroxine) replacement medication for a woman with pre-existing hypothyroidism should be adjusted to aim for a TSH level below 2.5 mIU/L prior to conception.
During Pregnancy
The traditional reference range used by the healthcare provider to diagnose and manage hypothyroidism is significantly narrower in pregnancy.
Complementary Alternative Medicine (CAM)
In addition to the traditional treatment of your hypothyroidism with thyroid hormone replacement, implementing lifestyle habits, mind-body practices, and dietary changes in your health care can offer many benefits.
The TSH level should be maintained at the following trimester-specific levels:
For example, some experts suggest that certain yoga poses (specifically, shoulder stands and inverted poses where the feet are elevated) may be beneficial to blood flow to the thyroid gland, or to the reduction of general stress that contributes to worsening symptoms of hypothyroidism.
Moreover, some people find that guided meditation is helpful for the thyroid, as are other stress-reducing strategies like prayer, gentle yoga, tai chi, and needlework.
Self-Treatment
It’s important to note that self-treating your thyroid problem with supplements is not a good idea. Treating an underactive thyroid is a complex process that requires careful symptom and dose monitoring by a practitioner.
Keep in mind, as well, that supplements are not regulated by the government, and there is no scientific consensus that they are safe and effective. In other words, just because a supplement is “natural” or available without a prescription does not necessarily mean that it’s harmless.
While some holistic or CAM practitioners may be able to recommend approaches to support your thyroid, immune and hormonal systems, it’s important to be cautious of any product that’s marketed as a “cure” for your disease, or marketed as being without side effects.
It’s important to be open and honest with your healthcare provider from the start about your use of complementary therapies, so you can ensure that nothing you’re doing (or want to try) will interfere with your thyroid care.
Frequently Asked Questions
- Is there a cure for hypothyroidism?
- There is no cure when hypothyroidism is caused by an autoimmune disorder or damage to the thyroid, but the condition can be treated with thyroid medications. You will have to take these medications for the rest of your life. Sometimes an underactive thyroid can be caused by certain medications. If it’s not an option to stop a medication that’s affecting your thyroid function, you can take other prescription drugs to counter the effect.
- Does hypothyroidism ever go away on its own?
- Viral hypothyroidism and pregnancy-related hypothyroidism may resolve on their own. In most cases, however, an underactive thyroid will get progressively worse, but you can manage the condition with proper medication and some lifestyle changes.
- What type of side effects does hypothyroidism medication cause?
- Levothyroxine, the most commonly prescribed medication for treating an underactive thyroid, can cause side effects such as:Weight changesHeadacheDiarrheaChanges in appetiteChanges in menstrual cycleHeat sensitivity Joint painIf you experience symptoms of an allergic reaction, get emergency help.
There is no cure when hypothyroidism is caused by an autoimmune disorder or damage to the thyroid, but the condition can be treated with thyroid medications. You will have to take these medications for the rest of your life. Sometimes an underactive thyroid can be caused by certain medications. If it’s not an option to stop a medication that’s affecting your thyroid function, you can take other prescription drugs to counter the effect.
Viral hypothyroidism and pregnancy-related hypothyroidism may resolve on their own. In most cases, however, an underactive thyroid will get progressively worse, but you can manage the condition with proper medication and some lifestyle changes.
Levothyroxine, the most commonly prescribed medication for treating an underactive thyroid, can cause side effects such as:
