Medically reviewed on Sept 20, 2023 by Jordan Stachel, M.S., RDN, CPT. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.
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If you’ve been diagnosed with hypothyroidism (also called an underactive thyroid), you know that healthcare providers typically treat the condition with medication, the most common of which is levothyroxine. This medication delivers the thyroid hormones to your body that your thyroid gland isn’t making on its own. 
Normally, taking levothyroxine will regulate thyroid hormone levels. However, different people receive different dosages, and it’s not unusual to transition dosages within your lifetime.  For these reasons, you may have trouble understanding your thyroid levels and whether your current dosage is sufficient.
Below, we’ll take a closer look at signs thyroid medication is too low, as well as steps for achieving an optimal dose in partnership with your healthcare provider.
If you’ve recently started taking thyroid medication, it can be frustrating to wait for your symptoms to abate or for clear signs your thyroid medication is working. However, most people need to take hypothyroid medicine daily for at least 4 weeks before noticing an improvement. 
If any of the following circumstances or signs have occurred, it may indicate your dosage needs to be readjusted.
Losing or gaining weight isn’t necessarily the result of an improper thyroid medication dosage. However, it may require you to reach out to a healthcare provider because your dosage is largely based on your body mass index (BMI) and body weight. [1,3]
For most American adults, the recommended dosage is between 1.5 to 1.8 micrograms (mcg) per kilogram (kg) of body weight.  Typically, the starting dosage of levothyroxine for adults who have an average body weight are as follows :
While every person is different, and managing thyroid conditions can look different for each individual, weight is an important factor in deciding what dosage your provider will prescribe. To that end :
On both occasions, it’s important to let your healthcare provider know about your weight changes. They’ll be able to gauge a dose that’s suitable for your current weight and current health concerns.
It’s very important to take levothyroxine correctly as irregularities in your thyroid management routine can interfere with how well the medicine is working. 
Some general guidelines for taking levothyroxine include :
It can be challenging to make a change and maintain it, even if those changes directly impact our health. However, consistency is crucial for treating hypothyroidism. If you’ve been struggling to take your medication regularly, you might try asking a loved one to remind you or setting alarms for yourself on your phone each morning.
In some cases, it may take up to 8 weeks to observe an improvement in hypothyroidism symptoms. Some of the most noticeable and common symptoms include :
After 8 weeks of taking your medication, your healthcare provider should take some bloodwork to screen your current thyroid hormone levels.  If they appear to be normal, it’s likely you’re at the appropriate dose. 
If your symptoms persist after 8 weeks and your healthcare provider has approved your current dosage, it’s a good idea to consult with them about your symptoms.  They may want to screen for other thyroid conditions or underlying health conditions. Or, they may recommend incorporating moderate lifestyle adjustments that may support your medication’s progress.
In a word, yes.1 When taken in the appropriate dose, levothyroxine shouldn’t cause significant side effects or discomfort.  To that end, if you do notice negative side effects or discomfort, it’s likely due to your dosage.
Often, an inappropriately high dose of levothyroxine can manifest with many symptoms trademark to hyperthyroidism.  Hyperthyroidism is a related condition that causes the thyroid gland to produce thyroid hormones in excess. 
If you observe any of the following symptoms, it could be a sign your levothyroxine dose is too high :
Hypothyroidism is projected to affect about 1 in 300 American adults (.3% of the population).7 Most people with hypothyroidism are assigned female at birth (AFAB) and fall into an advanced age range. 
Generally, levothyroxine is an effective treatment for those who are experiencing hypothyroidism. The most common interferences with its efficacy include :
To that end, managing hypothyroidism with a healthy lifestyle is a critical factor in supporting your medicinal protocol. For instance, introducing daily movement may help slow weight gain and improve muscle weakness. Treating hypothyroidism may mean combining both clinical and behavioral interventions.
See related: Can You Live Without a Thyroid?
As one of the keystone hormonal organs, your thyroid plays a vital role in several bodily functions, among them :
As many as 20 million Americans suffer from thyroid disease.  Even if you’ve been diagnosed with hypothyroidism or another thyroid disorder, there are proactive steps you can take to support your overall hormonal health.
One of the most beneficial steps you can take to support your thyroid is to maintain a balanced iodine intake.8 This is particularly important if you’re living with a diagnosed thyroid condition. 
Without sufficient iodine, the thyroid can’t produce thyroid hormones.8 And, because humans can’t produce iodine on their own, we must acquire it through food. 
Excellent sources of iodine include :
Ideally, adults should consume approximately 150 mcg of iodine daily.  However, pregnant people and people AFAB will need more iodine (220 mcg for pregnant people; 290 mcg for those who are breastfeeding). 
Remember, it’s important to avoid consuming iodine in excess, as inordinate amounts of iodine can cause complications in people with thyroid disorders.
A 2016 study from the Journal of the Academy of Nutrition and Dietetics indicated coffee may interfere with the efficacy of levothyroxine tablets.  However, liquid levothyroxine did not appear to be affected.
If you take tablets of levothyroxine, it’s a good idea to wait until after you take your daily pill to have your coffee.
Every body is different and responds differently to certain ingredients and food constituents. A substance that triggers inflammation in one person may not trigger it in another.
For instance, having an allergy or sensitivity to a certain food or food constituent may lead to higher-than-average levels of inflammation in the body. To identify your food triggers, you might consider testing for allergies or sensitivities at home or with a healthcare provider.
Additionally, most individuals could benefit from reducing their consumption of highly processed foods, which tend to trigger inflammatory responses.  Inflammatory foods are typically :
Excessive amounts of red meats and omega-6 fatty acids may also lead to inflammation.  If you’re unsure of where to start, aim to fill your plate with whole ingredients, whole grains, and lean protein sources.
If you’re unsure about your thyroid medication dosage, consult a licensed clinician using Everlywell’s online thyroid services. From the comfort of your own home, you can start to address your thyroid symptoms and determine whether your dosage is right for you.
Curious to learn more about your thyroid health? Test for abnormal thyroid hormone levels at home with the at-home Thyroid Blood Test. With physician-reviewed results you can trust, you can begin to make sense of your symptoms and schedule a digital consultation if needed.
Everlywell connects people taking action on their health at home to a vetted network of healthcare professionals and prescription services. Find out more about how it works by visiting Everlywell today.