Levothyroxine (Tirosint) is a thyroid hormone used to treat hypothyroidism in adults and children ages 6 and older. It's available as a capsule in many different strengths. The capsule is usually taken once a day in the morning, about 30 minutes to 1 hour before breakfast, on an empty stomach. Common side effects include headache, nervousness, trouble sleeping, and weight loss. But it's important to note that this medication isn’t intended to be used for weight loss.
Levothyroxine (Tirosint) is a lab-made version of the thyroid hormone called thyroxine or T4 that's made by your thyroid gland. Thyroid hormones have important functions like controlling your metabolism, body temperature, heart rate, and more. When the amount of hormone is too low, taking thyroid replacement hormones can bring your levels back to normal.
The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Signs of having too much thyroid hormones in the body, such as:
Contact your healthcare provider immediately if you experience any of the following.
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
Less common
Chest pain or discomfort
decreased urine output
difficult or labored breathing
difficulty with swallowing
dilated neck veins
extreme fatigue
fainting
fast, slow, irregular, pounding, or racing heartbeat or pulse
heat intolerance
hives or welts, skin itching, rash, or redness
irregular breathing
irritability
menstrual changes
pain or discomfort in the arms, jaw, back, or neck
sweating
swelling of the eyes, face, lips, throat, or tongue
tightness in the chest
Get emergency help immediately if any of the following symptoms of overdose occur:
Symptoms of overdose
Change in consciousness
cold, clammy skin
confusion
disorientation
fast or weak pulse
lightheadedness
loss of consciousness
sudden headache
sudden loss of coordination
sudden slurring of speech
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
Less common
Abdominal or stomach cramps
change in appetite
crying
false or unusual sense of well-being
fear or nervousness
feeling not well or unhappy
feeling of discomfort
feeling of warmth
feeling things are not real
feelings of suspicion and distrust
headache
increased appetite
mental depression
muscle weakness
quick to react or overreact emotionally
rapidly changing moods
redness of the face, neck, arms, and occasionally, upper chest
restlessness
trouble getting pregnant
trouble sitting still
unusual tiredness or weakness
vomiting
weight gain or loss
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
It can take up to 4 to 6 weeks after you start levothyroxine (Tirosint) before you experience the full benefit this medication. But some people might notice an improvement in their symptoms sooner than that. If you're starting levothyroxine (Tirosint) for the first time, it might take months before your prescriber can find a dose that works best for you. During this time, they'll order blood work to check your thyroid hormone levels to make sure it's within the target range. Your prescriber might need to raise your dose slowly over time, to avoid side effects of having too much thyroid hormone, such as anxiety, headache, and nausea.
Levothyroxine (Tirosint) interacts with many medications. Some interactions lead reduce the absorption of levothyroxine (Tirosint), which means it won't work as well. And others can lead to too levothyroxine (Tirosint) in your body. To avoid these interactions, it's recommended to take levothyroxine (Tirosint) on an empty stomach. How long you should wait between taking it and other medications can depend on the specific medication. For example, some antacids (e.g., calcium carbonate) should be taken 4 hours away from levothyroxine (Tirosint). Check with your pharmacist or prescriber for how long you should wait before taking your other medications.
Eating too soon after taking levothyroxine (Tirosint) can make it harder for your body to absorb the medication. For example, foods high in fiber, soy products, and walnuts can reduce the absorption of levothyroxine (Tirosint). For this reason, it's recommended to take your dose at least 30 minutes to 1 hour before food.
You can take levothyroxine (Tirosint) at bedtime, but make sure it's 4 hours after the last meal. Research shows levothyroxine (Tirosint) can work just as well at night as it does in the morning, as long as you separate it from food and other medications.
Try to wait 1 hour after taking your dose of levothyroxine (Tirosint) before drinking coffee. Drinking coffee with levothyroxine (Tirosint) can lower the amount of medication your body absorbs.
Weight gain isn't a known side effect of levothyroxine (Tirosint). But it's possible for you to experience weight gain while taking this medication if the dose of levothyroxine (Tirosint) isn't enough to bring your thyroid hormone levels up to the target range. If you have weight gain while taking levothyroxine (Tirosint), let your prescriber know. They might need to check your thyroid hormone level to make sure your dose is appropriate.
Levothyroxine (Tirosint) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Levothyroxine (Tirosint) shouldn't be used for weight loss. It’s not recommended, safe, or effective for this use. Taking high doses of levothyroxine (Tirosint) can cause serious or life-threatening effects, especially if used with other medications for weight loss.
Taking too much levothyroxine (Tirosint) can cause heart problems, especially for older adults or people with heart conditions. Call your prescriber or get medical care right away if you have rapid or irregular heartbeat, chest pain, or trouble breathing. Your prescriber might need to reduce your dose or have you stop taking the medication altogether if you experience new heart problems.
In rare cases, some people can have low thyroid hormones and low adrenal hormones at the same time. If you have conditions, such as Addison's disease, where your body has low adrenal hormone levels, let your prescriber know. It's important that they treat your hormone levels first before they treat your thyroid condition. Otherwise, receiving thyroid hormones first can cause your adrenal hormones to drop even lower and make you feel unwell. Your prescriber should check your adrenal hormones before prescribing levothyroxine (Tirosint). If you experience long-lasting tiredness, stomach pain, dizziness, weakness, or vomiting while taking this medication, seek medical attention right away.
Levothyroxine (Tirosint) can raise your blood sugar levels, especially when you first start this medication and when your dose is raised. If you already have diabetes, your prescriber might need to adjust the dose of your blood sugar medications. Check your blood sugar levels as directed by your prescriber. Talk to your them if the levels are higher than usual.
Taking levothyroxine (Tirosint) can weaken bones over time, especially if your dose is too high. The risk is higher for women after menopause . To lower your risk, your prescriber will be monitoring your thyroid levels to make sure you're taking the lowest dose needed to treat your thyroid condition. Make sure to get plenty of exercise, eat a bone-healthy diet, and avoid alcohol to lower your risk of bone problems.
| Dosage | Quantity | Price as low as | Price per unit |
|---|---|---|---|
| 30 capsules of 13mcg | 1 box | $89.67 | $89.67 |
| 30 capsules of 25mcg | 1 box | $104.17 | $104.17 |
| 30 capsules of 50mcg | 1 box | $122.37 | $122.37 |
| 30 capsules of 75mcg | 1 box | $113.08 | $113.08 |
| 30 capsules of 112mcg | 1 box | $78.25 | $78.25 |
| 30 capsules of 125mcg | 1 box | $103.53 | $103.53 |
| 30 capsules of 137mcg | 1 box | $72.05 | $72.05 |
| 30 capsules of 150mcg | 1 box | $106.76 | $106.76 |
| 30 capsules of 88mcg | 1 box | $110.72 | $110.72 |
| 30 capsules of 100mcg | 1 box | $96.71 | $96.71 |
| 30 capsules of 175mcg | 1 box | $103.43 | $103.43 |
| 30 capsules of 200mcg | 1 box | $120.24 | $120.24 |
| 30 capsules of 62.5mcg | 1 box | $127.54 | $127.54 |
| 30 capsules of 37.5mcg | 1 box | $127.54 | $127.54 |
| 30 capsules of 44mcg | 1 box | $127.54 | $127.54 |
Your provider will calculate your dose of levothyroxine (Tirosint) based on different factors, such as your age, medical condition, other medications you're taking, and the thyroid hormone levels in your blood.
The typical dose of levothyroxine (Tirosint) ranges from 13 mcg to 200 mcg taken by mouth once daily on an empty stomach.
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Contraindications are specific health conditions or situations in which a person should not take a medication due to safety concerns. If you have any of the following conditions or if any of the following apply to you, let your healthcare provider know because Levothyroxine (Tirosint) will not be safe for you to take.