Thyroid Medication Q&A

At Thyroid Virtual Clinic we are contacted by patients every day with questions or concerns about their thyroid medication.

These typically include questions regarding branded vs. generic, more traditional medications vs. more “natural” alternatives, best practices for taking thyroid medication, as well as concerns over realistic expectations for medication efficacy, and how to achieve the proper/optimal dosage. With this in mind, we offer the following information to help guide thyroid patients in connection with their medication choices and regimen.

Questions & Answers

  • I have hypothyroidism (underactive thyroid). Should I take a branded or generic medication for my condition?

      Hypothyroidism (underactive thyroid) is usually treated with an oral form of T4 replacement hormone (levothyroxine). These include both generic levothyroxine (or l-thyroxine) and branded tablets (Synthroid, Levoxyl, Unithroid, Levothroid) as well as gel capsules (Tirosint), with all of these formulations generally being equally effective. Either use of brand name levothyroxine (the most well-known being Synthroid), or the same generic preparation (made by the same manufacturer) is generally recommended, since switching between levothyroxine products made by different manufacturers could potentially cause issues. Specifically, it can result in abnormal thyroid hormone blood levels and unnecessary changes in doses, so should generally be avoided. If a switch is necessary, a blood test can be done 5-6 weeks after the switch to determine if the dose needs to be adjusted.

  • How should I take my thyroid medicine?

      Levothyroxine (either brand or generic) should be taken once per day on an empty stomach (ideally 1 hour before breakfast or 3 hours after the last meal of the day). If this is inconvenient, 30-45 minutes before breakfast is the next best choice.  If levothyroxine is taken closer to (or with) a meal, or together with other medications, vitamins or supplements, its absorption may be reduced, which may lead to fluctuating blood levels and unnecessary dose changes.  While most medications may be taken 30-45 minutes after taking levothyroxine, calcium, iron, or any vitamins containing these minerals should be taken at least 4 hours after your dose.

      It is imperative to take your thyroid medications as prescribed by your doctor. Even occasional skipping of your thyroid medication may result in abnormal blood levels and cause symptoms of hypothyroidism.  Therefore, if you ever miss your morning dose, take it either 3 hours after your last meal or take a double dose the following morning.

  • How does TVC handle thyroid medication prescriptions and refills?

      After your initial or follow-up evaluation, a TVC clinician will send a prescription for your medication to a pharmacy of your choice for a 30- or 90-day supply, with enough refills to provide you with enough medication for at least 2 weeks after your next planned follow-up.  However, if for some reason you are going to run out of your medication before your next follow-up, you should request it from TVC by sending a secure message from your patient portal at least a week before you run out of your medication (or 2 weeks if you are planning to receive it from a mail order pharmacy). Alternatively, you can ask your pharmacy to request a refill from TVC electronically on your behalf.  Always make sure to check the number of the remaining refills on your medication bottle – if it is not zero, you can just ask your pharmacy to provide you with a refill.

  • What should I do if I forgot to request a refill and ran out of my thyroid medicine?

      As soon as you realize that you have no more medicine, you should request a refill from TVC by sending a secure message from your patient portal. Alternatively, you can ask your pharmacy to request a refill from TVC electronically on your behalf. However, always keep in mind that TVC responds to patient requests the same or next business day (Monday-Friday 9am-5pm EST, excluding holidays). Although it is recommended to take your thyroid medication every day (unless otherwise prescribed), it is not uncommon for thyroid patients to occasionally run out of medication and miss their dose for a few days. Contrary to popular belief, it is safe and effective to take a double dose of levothyroxine (T4), or it’s branded equivalent, for 1-2 days if a dose (or doses) is (are) missed. However, if you are taking a medication containing T3 (such as Cytomel, Armour thyroid, Naturethroid and others) or medications for hyperthyroidism (methimazole or PTU), do not double the dose as it may cause undesirable side effects.

  • What are typical side effects of thyroid medications for hypothyroidism (underactive thyroid)?

      Levothyroxine (and its branded equivalents) does (do) not generally have side effects if the correct dose is given. If the dose is too high, you may experience symptoms of hyperthyroidism. Rarely, people may be allergic to the dyes or fillers commonly found in levothyroxine tablets.  Medication containing T3 (such as Cytomel, Armour thyroid, Naturethroid and some others) are more likely to cause symptoms of hyperthyroidism.  TVC clinicians will determine what dose and preparation is right for you to minimize the risk of overtreatment and side effects while maximizing efficacy.

  • When should I start feeling better after starting a new medication or changing the dose of an existing medication?

      In most cases, symptoms of hypothyroidism start to improve within 2-3 weeks of starting a new thyroid medication or adjusting the dose of an existing medication. However, people with more severe symptoms may require a longer duration of treatment before they feel significantly better.

  • How can I tell if my levothyroxine dose is too high for me?

      The main symptoms of overtreatment with levothyroxine include anxiety, hand shaking, rapid heartbeat, sleep problems, and weight loss.  If you start experiencing any of those symptoms after starting levothyroxine treatment or increasing your dose, you should inform your physician.  Do not make any dosage change (or discontinue your medication) before consulting with your physician.

  • How do I (or my physician) know if my dose is correct?

      Generally, you should have your TSH blood level tested after 5-6 weeks of initiating medication treatment or changing your dose.  Your dose can be adjusted after the test results are reviewed, depending on the results and the presence/severity of symptoms.  This process may need to be repeated a few times before the blood level of thyroid hormone becomes normal.  Most people with hypothyroidism require lifelong treatment, and the dose of levothyroxine may need to be adjusted over time.

  • Why do my thyroid levels often fluctuate resulting in my levothyroxine dose being changed by my doctor?

      There are many circumstances that may lead to fluctuating thyroid levels.  They include: improper administration of (or skipping) your thyroid medication; switches between different levothyroxine formulations (brand to generic, or from one generic to another); having a blood test done while being ill (or recovering from an illness);  weight changes; taking other (non-thyroid) medications that may affect the thyroid blood level; laboratory errors, and other causes.  Sometimes physicians recommend changing the levothyroxine dose rather than investigating the root cause of a patient’s abnormal thyroid levels, which may lead to over- or undertreatment, and cause different symptoms, and sometimes potentially dangerous side effects, prompting another round of changes, and so forth.

  • Why don’t I feel well despite my doctor telling me that my thyroid blood level is normal and medication dose is correct?

      Many symptoms that people attribute to thyroid disease may be unrelated to it, resulting in those having a normal thyroid level still not feeling well.  However, there may be situations when a person’s thyroid level may be seemingly “normal” when compared to the laboratory reference range for the general population, but may not be normal for that individual.  Sometimes the expertise of a thyroid specialist is required to determine if your thyroid blood level is truly “normal” for you and if your thyroid medication dose is appropriate.  TVC clinicians will determine if there is a possibility of adjusting your “correct” dose to make you feel better.

  • Are there any benefits from medications other than levothyroxine, containing T3 (such as Armour Thyroid, Naturethroid, Cytomel, and others)?

      While some clinicians prescribe those medications, the majority of studies have not shown any advantage of those medications over levothyroxine.   Moreover, those medications are harder to adjust, and their administration may occasionally lead to undesirable side effects.  However, occasionally we do come across patients who feel better on those medications compared to levothyroxine.  While TVC clinicians do not generally recommend taking those medications, they may selectively prescribe them to some patients after a thorough evaluation.

  • I have hyperthyroidism (overactive thyroid). What do I need to know about my thyroid medication?

      Unlike medications for hypothyroidism, medications for hyperthyroidism (methimazole and PTU) have several side effects. Minor side effects include itching, rash, joint pain, nausea and vomiting.  Major side effects are rare, but may be very serious if they do occur. They can include reduction in white blood cell count (which may lead to life-threatening infection), inflammation of blood vessels, liver damage and severe anemia (inability of bone marrow to produce different types of blood cells). Treatment for hyperthyroidism may take a long time (at least a year and often significantly longer) with comprehensive monitoring required. It is imperative not to miss your medication for hyperthyroidism even for a few days, since the cumulative effect of treatment may be lost. TVC clinicians will determine what dose and preparation is right for you to minimize the risk of side effects while maximizing efficacy.