Free T3

Optimal Result: 266 - 938 ng/g creatinine.

Other names for a T3 test include:

→ Thyroid function test.

→ Total triiodothyronine.

→ Free triiodothyronine.

→ FT3.

What is a thyroid?

The thyroid is a small, butterfly-shaped gland located at the base of the neck, just below Adam's apple. It’s a part of your endocrine system.  The thyroid gland makes two main hormones: thyroxine (T-4) and triiodothyronine (T-3). These hormones affect every cell in the body. They support the rate at which the body uses fats and carbohydrates. They help control body temperature. They have an effect on heart rate. And they help control how much protein the body makes.

The thyroid’s job is to make thyroid hormones, which are secreted into the blood and then carried to every tissue in the body. Thyroid hormones help the body use energy, stay warm and keep the brain, heart, muscles, and other organs working as they should.

The major thyroid hormone secreted by the thyroid gland is thyroxine, also called T4 because it contains four iodine atoms. To exert its effects, T4 is converted to triiodothyronine (T3) by the removal of an iodine atom. This occurs mainly in the liver and in certain tissues where T3 acts, such as in the brain. The amount of T4 produced by the thyroid gland is controlled by another hormone, which is made in the pituitary gland located at the base of the brain, called thyroid stimulating hormone (abbreviated TSH). The amount of TSH that the pituitary sends into the bloodstream depends on the amount of T4 that the pituitary sees. If the pituitary sees very little T4, then it produces more TSH to tell the thyroid gland to produce more T4. Once the T4 in the bloodstream goes above a certain level, the pituitary’s production of TSH is shut off. In fact, the thyroid and pituitary act in many ways like a heater and a thermostat. When the heater is off and it becomes cold, the thermostat reads the temperature and turns on the heater. When the heat rises to an appropriate level, the thermostat senses this and turns off the heater. Thus, the thyroid and the pituitary, like a heater and thermostat, turn on and off.

T3, or triiodothyronine, is a thyroid hormone produced in small amounts by the thyroid gland. Free T3 is an active thyroid hormone. Reverse T3 may also be measured, however it is inactivated T3.

T4 and T3 circulate almost entirely bound to specific transport proteins. If the levels of these transport proteins changes, there can be changes in how much bound T4 and T3 is measured. This frequently happens during pregnancy and with the use of birth control pills. The “free” T4 or T3 is the hormone that is unbound and able to enter and affect the body tissues.

What is Triiodothyronine/T3?

Triiodothyronine, or T3, is an important thyroid hormone that helps maintain muscle control, brain function and development, heart and digestive functions. The thyroid gland makes T3 in response to thyroid stimulating hormone (TSH). TSH is made by the pituitary gland in your brain. 

Triiodothyronine is referred to as T3 because this hormone has three iodine atoms attached to it. The other major thyroid hormone, thyroxine or T4, has four iodine atoms. Some of the T3 circulating in your body is made in the thyroid. Most of it, however, starts as T4 and then is converted in the blood into T3 by the removal of an iodine atom.

More than 99% of the T3 in the body is bound to proteins as it circulates in the bloodstream. A small proportion, free T3, is not attached to proteins. Only the free T3 can act on cells and stimulate many physical processes. The body regulates the relationship between bound and free T3 in a fine balance to ensure proper body functions.

The total T3 test measures both bound and free T3, while the free T3 test measures only the T3 that is not attached to protein.

T3 measurements are typically used along with other thyroid function tests, like TSH and free and total T4, to evaluate how your thyroid functions.

Triiodothyronine comes in two forms:

Free T3: This form enters your body’s tissues where it's needed.

Bound T3: This form attaches to proteins, which prevents it from entering your body’s tissues.

Most of the T3 (approximately 80%) in your blood is from your body’s conversion of T4 into T3 outside of your thyroid gland. The rest of the T3 in your bloodstream is produced by your thyroid gland.

Hormones are chemicals that coordinate different functions in your body by carrying messages through your blood to your organs, muscles and other tissues. These signals tell your body what to do and when to do it.

T3 is the active form of thyroid hormone, meaning it impacts cells in your body, whereas T4 is the inactive form of thyroid hormone. Your liver and kidneys convert most of the T4 your thyroid releases into T3.

T3 works with another thyroid hormone called T4 to help control how your body stores and uses energy to do its work (metabolism). The thyroid hormones help control many of your body's other processes, including:

→ Metabolic rate (the rate at which your body transforms the food you eat into energy).

→ Heart and digestive functions.

→ Muscle control.

→ Brain development.

→ Bone maintenance.

→ Breathing

→ Nervous system function

→ Body temperature

→ Cholesterol level

→ Moisture in the skin

→ Menstruation

What is T3, Free?

Triiodothyronine, also known as T3, is one of the two main hormones your thyroid gland releases into your bloodstream. Your thyroid also produces thyroxine, also known as T4 and tetraiodothyronine. T4 and T3 work together and are commonly referred to as “thyroid hormone.”

What is a T3 test?

A T3 (=triiodothyronine) test is a blood test that helps diagnose thyroid conditions, specifically hyperthyroidism (overactive thyroid). Healthcare providers typically order this test alongside other thyroid function tests.

High or low T3 levels may indicate an overactive or underactive thyroid.

According to the American Thyroid Association (ATA), T3 tests are most useful for diagnosing hyperthyroidism. They are less helpful in diagnosing hypothyroidism.

Healthcare providers test T3 levels using blood tests. 

The tests for free T3 are generally less accurate than for total T3.

Free T3 or total T3 blood tests may be ordered to evaluate thyroid function if a thyroid disorder is suspected. They may also be used to evaluate pituitary gland problems, assess the severity and type of thyroid disease, and monitor treatment for a thyroid condition.

What are normal T3 levels?

Normal T3 level ranges vary based on age. In general, normal ranges for T3 for healthy people include:

→ Children 1 to 5 years old: 106 – 203 nanograms per deciliter (ng/dL).

→ Children 6 to 10 years old: 104 – 183 ng/dL.

→ Children 11 to 14 years old: 68 – 186 ng/dL.

→ Adolescents 15 to 17 years old: 71 – 175 ng/dL.

→ Adults 18 to 99 years old: 79 – 165 ng/dL.

Normal free T3 levels:

→ Infants up to 3 days old: 1.4 – 5.4 picograms per milliliter (pg/mL).

→ Infants 4 to 30 days old: 2.0 – 5.2 pg/mL.

→ Babies 1 month to 1 year old: 1.5 – 6.4 pg/mL.

→ Children 1 to 6 years old: 2.0 – 6.0 pg/mL.

→ Children 7 to 11 years old: 2.7 – 5.2 pg/mL.

→ Children 12 to 17 years old: 2.3 – 5.0 pg/mL.

→ Adults 18 to 99 years old: 2.3 – 4.1 pg/mL

The standard lab reference range for free T3 is 2.0−4.4 pg/mL.

What are other thyroids tests?

Thyroid stimulating hormone (TSH): 

Changes in TSH levels can be an early warning sign of a thyroid condition, even if other thyroid hormone levels are still normal.

Thyroxine (T4)

T4 is the other major hormone that the thyroid produces alongside T3. High or low T4, especially in conjunction with unusual TSH levels, can indicate a thyroid condition.

Thyroid antibody tests: 

Antibodies are part of the body’s immune defences. However, some people develop thyroid conditions when the body mistakenly attacks the thyroid. Antibody tests can help a doctor diagnose this issue.

Radioactive iodine uptake: 

This test involves the person swallowing a small amount of iodine. The thyroid uses iodine to make T4, so by scanning the thyroid, doctors can see how well the thyroid is taking up iodine.

What do my test results mean?

Test results may vary depending on your age, gender, health history, and other things. Your test results may be different depending on the lab used. They may not mean you have a problem. 

What might affect my test results?

Taking thyroid hormone medicines or certain other medicines, such as estrogen or methadone, can affect your test results. Eating a diet high in iodine-rich foods, such as seaweed, may also affect your test results.

T3 Test Results:








Normal thyroid function




Subclinical hypothyroidism




The finding of an elevated TSH and low FT4 or FTI indicates primary hypothyroidism due to disease in the thyroid gland. 

Low (or undetectable)



Secondary hypothyroidism related to the pituitary gland




A low TSH with an elevated FT4 or FTI is found in individuals who have hyperthyroidism.



Low or Normal

A low TSH and low FT4 or FTI indicates hypothyroidism due to a problem involving the pituitary gland.

Normal or High



Secondary hyperthyroidism related to pituitary gland

Subclinical hypothyroidism and hyperthyroidism are conditions defined by abnormal TSH test results with normal T3 and T4 levels. These subclinical conditions often cause no symptoms or only very mild ones. Some subclinical thyroid conditions may progress to outright hypothyroidism or hyperthyroidism over time.

Why is a TSH test important as well?

The best way to initially test thyroid function is to measure the TSH level in a blood sample. Changes in TSH can serve as an “early warning system” – often occurring before the actual level of thyroid hormones in the body becomes too high or too low. 

A high TSH level indicates that the thyroid gland is not making enough thyroid hormone (primary hypothyroidism). 

The opposite situation, in which the TSH level is low, usually indicates that the thyroid is producing too much thyroid hormone (hyperthyroidism). 

Occasionally, a low TSH may result from an abnormality in the pituitary gland, which prevents it from making enough TSH to stimulate the thyroid (secondary hypothyroidism). 

In most healthy individuals, a normal TSH value means that the thyroid is functioning properly.

Why is the T4 test important as well (free & bound)?

T4 is the main form of thyroid hormone circulating in the blood. A Total T4 measures the bound and free hormone and can change when binding proteins differ. A Free T4 measures what is not bound and able to enter and affect the body tissues. Tests measuring free T4 – either a free T4 (FT4) or free T4 index (FTI) – more accurately reflect how the thyroid gland is functioning when checked with a TSH.

→ The finding of an elevated TSH and low FT4 or FTI indicates primary hypothyroidism due to disease in the thyroid gland. 

→ A low TSH and low FT4 or FTI indicates hypothyroidism due to a problem involving the pituitary gland.

→ A low TSH with an elevated FT4 or FTI is found in individuals who have hyperthyroidism.

What is the Reverse T3 test?

Reverse T3 is a biologically inactive protein that is structurally very similar to T3, but the iodine atoms are placed in different locations, which makes it inactive. Some reverse T3 is produced normally in the body, but is then rapidly degraded. In healthy, non-hospitalized people, measurement of reverse T3 does not help determine whether hypothyroidism exists or not, and is not clinically useful.

What is the Thyroid Antibody test?

The immune system of the body normally protects us from foreign invaders such as bacteria and viruses by destroying these invaders with substances called antibodies produced by blood cells known as lymphocytes. In many patients with hypothyroidism or hyperthyroidism, lymphocytes react against the thyroid (thyroid autoimmunity) and make antibodies against thyroid cell proteins. Two common antibodies are thyroid peroxidase antibody and thyroglobulin antibody. Measuring levels of thyroid antibodies may help diagnose the cause of the thyroid problem. For example, positive anti-thyroid peroxidase and/or anti-thyroglobulin antibodies in a patient with hypothyroidism result in a diagnosis of Hashimoto’s thyroiditis. While detecting antibodies is helpful in the initial diagnosis of hypothyroidism due to autoimmune thyroiditis, following their levels over time is not helpful in detecting the development of hypothyroidism or response to therapy. TSH and FT4 are what tell us about the actual thyroid function or levels.

A different antibody that may be positive in a patient with hyperthyroidism is the stimulatory TSH receptor antibody (TSI). This antibody causes the thyroid to be overactive in Graves’ Disease. If you have Graves’ disease, your doctor might also order a thyrotropin receptor antibody test (TSHR or TRAb), which detects both stimulating and blocking antibodies. Following antibody levels in Graves’ patients may help to assess response to treatment of hyperthyroidism, to determine when it is appropriate to discontinue antithyroid medication, and to assess the risk of passing antibodies to the fetus during pregnancy.

What is the Thyroglobulin test?

Thyroglobulin is a protein produced by normal thyroid cells and thyroid cancer cells. It is not a measure of thyroid function and it does not diagnose thyroid cancer when the thyroid gland is still present. It is used most often in patients who have had surgery for thyroid cancer in order to monitor them after treatment. Thyroglobulin is not a primary measure of thyroid hormone function.

Medications that might interfere with Thyroid function testing:

There are many medications that can affect thyroid function testing. Some common examples include:

Estrogens, such as in birth control pills, or in pregnancy, cause high levels of total T4 and T3. This is because estrogens increase the level of the binding proteins. In these situations, it is better to ask both for TSH and free T4 for thyroid evaluation, which will typically be in the normal range.

Biotin, a commonly taken over-the-counter supplement, can cause the measurement of several thyroid function tests to appear abnormal, when they are in fact normal in the blood. Biotin should not be taken for 2 days before blood is drawn for thyroid function testing to avoid this effect.

Primary Hyperthyroidism:

A low TSH and a high thyroid hormone level (e.g. high FT4) can indicate primary hyperthyroidism. Primary hyperthyroidism occurs when the thyroid gland makes or releases too much thyroid hormone. Symptoms of hyperthyroidism can include tremors, palpitations, restlessness, feeling too warm, frequent bowel movements, disrupted sleep, and unintentional weight loss.

Causes of primary hyperthyroidism include:

→ Graves' disease

→ Toxic or autonomously functioning thyroid nodule

→ Multinodular goiter

→ Thyroid inflammation (called thyroiditis) early in the course of disease

→ Thyroid gland dysfunction due to a medication (e.g. amiodarone or cancer immunotherapy)

→ Excess thyroid hormone therapy

Early or mild hyperthyroidism may present as a persistently low TSH and a normal FT4 hormone level. This pattern is called subclinical hyperthyroidism and your doctor may recommend treatment. Over time, untreated subclinical hyperthyroidism can worsen osteoporosis and contribute to abnormal heart rhythms.

Thyroiditis (Thyroid inflammation):

Thyroid inflammation, also called thyroiditis, causes injury to the thyroid gland and release of thyroid hormone. Individuals with thyroiditis usually have a brief period of hyperthyroidism (low TSH and high FT4 or Total T4) followed by development of hypothyroidism (high TSH and low FT4 or Total T4) or resolution.

Some forms of thyroiditis are transient, like postpartum thyroiditis or thyroiditis following an infection, and often resolve on their own without need for medication.

Other forms of thyroiditis, like thyroiditis resulting from cancer immunotherapy, interferon alpha, or tyrosine kinase inhibitors, usually result in permanent hypothyroidism and require long term treatment with thyroid hormone replacement.

Your endocrinologist will monitor your thyroid tests during thyroiditis and can help determine if you need short- and long-term medications to balance your thyroid function and control any symptoms.

Central Hypothyroidism:

A low TSH and a low FT4 may indicate pituitary disease. Detection of central hypothyroidism should prompt your doctor to check for problems in other pituitary hormones, an underlying cause, and you may need imaging tests to look at the pituitary gland.

Central hypothyroidism is treated with thyroid hormone replacement. Importantly, adequacy of thyroid replacement in central hyperthyroidism is assessed with FT4 and Total T4 tests not TSH as in primary hyperthyroidism, and deficiency in stress hormone cortisol should be assessed before starting thyroid treatment to prevent an adrenal crisis. 

Causes of central hypothyroidism include pituitary gland disease, such as a pituitary mass or tumor, history of pituitary surgery or radiation, pituitary inflammation (called hypophysitis) resulting from autoimmune disease or cancer immunotherapy, and infiltrative diseases.

Rare causes of abnormal thyroid function:

→ Thyroid hormone resistance

→ Iodine induced hyperthyroidism

→ TSH-secreting tumor (TSH-oma)

→ Germ cell tumors

→ Trophoblastic disease

→ Infiltrative diseases, such as systemic scleroderma, hemochromatosis, or amyloidosis.

When abnormal thyroid function tests are not due to thyroid disease:

While blood tests to measure thyroid hormones and thyroid stimulating hormone (TSH) are widely available, it is important to remember that not all tests are useful in all circumstances and many factors including medications, supplements, and non-thyroid medical conditions can affect thyroid test results. An endocrinologist can help you make sense of thyroid test results when there is a discrepancy between your results and how you feel. A good first step is often to repeat the test and ensure there are no medications that might interfere with the test results. Below are some common reasons for mismatch between thyroid tests and thyroid disease.

How is hypothyroidism treated?

Levothyroxine is the standard of care in thyroid hormone replacement therapy and treatment of hypothyroidism. Levothyroxine (also called LT4) is equivalent to the T4 form of naturally occurring thyroid hormone and is available in generic and brand name forms. For patients with celiac disease (autoimmune disease against gluten) or gluten sensitivity, a gluten free formulation of levothyroxine is available. Some individuals may have genetic variants that affect how the body converts T4 to T3 and these individuals may benefit from the addition of a small dose of triiodothyronine.

Liothyronine is a replacement T3 (triiodothyronine) thyroid hormone. This medication has a short half-life and is taken twice per day or in combination with levothyroxine. Liothyronine alone is not used for treatment of hypothyroidism long term.

Other formulations of thyroid hormone replacement include natural or desiccated thyroid hormone extracts from animal sources. Natural or desiccated thyroid extract preparations have greater variability in the dose of thyroid hormone between batches and imbalanced ratios if T4 vs T3. Natural or animal sources of thyroid hormone typically contain 75% T4 and 25% T3, compared to the normal human balance of 95% T4 and 5% T3. Treatment with a correct balance of T4 and T3 is important to replicate normal thyroid function and prevent adverse effects of excess T3, including osteoporosis, heart problems, and mood and sleep disturbance. An endocrinologist can evaluate symptoms and thyroid tests to help balance thyroid hormone medications.

What does it mean if your Free T3 result is too low?

Free T3 levels can appear low in a dried urine test in women due to several factors that influence thyroid hormone metabolism. This can be indicative of an underlying thyroid dysfunction. One possible reason is that dried urine tests primarily measure hormones and their metabolites excreted through urine, but they may not provide a comprehensive picture of thyroid function. Serum or blood tests are typically more accurate for assessing thyroid hormones, including Free T3. Additionally, urinary excretion of Free T3 can vary throughout the day, making it less reliable for diagnosis.

Low Free T3 levels in a dried urine test may also result from factors such as stress, certain medications, or dietary deficiencies. Stress can lead to alterations in thyroid hormone metabolism, potentially reducing Free T3 levels. Medications like glucocorticoids can affect thyroid function, leading to low Free T3. Furthermore, inadequate iodine intake or specific dietary patterns may contribute to thyroid dysfunction, impacting Free T3 levels.

In summary, while dried urine tests offer valuable insights into hormonal balance, they may not provide the most accurate assessment of thyroid function, especially for Free T3. To evaluate thyroid health comprehensively, healthcare providers often rely on a combination of serum thyroid hormone tests and clinical evaluation to make an accurate diagnosis in women.

Frequently asked questions

Unlock Your Health Journey with! Ever wished for a one-stop digital health haven for all your lab tests? Look no further! is your personalized health dashboard, bringing together test reports from any lab. Say goodbye to scattered results—organize and centralize your lab data effortlessly. Dive into the details of each biomarker and gain insights into the meaning behind your medical test data.

Join the community of thousands who've transformed the way they understand their lab results. Experience the joy of having all your lab data neatly organized, regardless of where or when the tests were done.

For our professional users, is a game-changer. Revel in the intuitive tools that not only streamline analysis but also save valuable time when delving into your client's lab report history. It's not just a dashboard; it's your gateway to a smarter, more informed health journey! personal account provides in-depth research on 4000+ biomarkers, including information and suggestions for test panels such as, but not limited to:

  • The GI Effects® Comprehensive Stool Profile,
  • GI-MAP,
  • The NutrEval FMV®,
  • The ION Profile,
  • Amino Acids Profile,
  • Dried Urine Test for Comprehensive Hormones (DUTCH),
  • Organic Acids Test,
  • Organix Comprehensive Profile,
  • Toxic Metals,
  • Complete Blood Count (CBC),
  • Metabolic panel,
  • Thyroid panel,
  • Lipid Panel,
  • Urinalysis,
  • And many, many more.

You can combine all test reports inside your Healthmatters account and keep them in one place. It gives you an excellent overview of all your health data. Once you retest, you can add new results and compare them.

If you are still determining whether Healthmatters support your lab results, the rule is that if you can test it, you can upload it to Healthmatters.

While we do talk about popular labs, we welcome reports from lots of other places too. It's as simple as this: if you can get a test done, you can upload it to Healthmatters. We can interpret results from any lab out there. If laboratories can analyze it, we can interpret it.

Still on the hunt for a specific biomarker? Just tell us, and we'll add it to our database. Anything from blood, urine, saliva, or stool can be uploaded, understood, and tracked with your Healthmatters account!

There are two ways to add your test reports to your account. One option is to input the data using the data entry forms. The other method is to utilize our "Data entry service."

Our data entry forms offer an easy, fast, and free way for you to input the reports yourself. Self-entry allows you to add an unlimited number of reports at no cost. We make the self-entry process user-friendly, providing dozens of templates that pre-populate the most popular laboratory panels and offering instant feedback on entered values.

For those who prefer assistance, we offer a "Data entry service" to help you input your data. Simply attach an image or file of your lab test results, and a qualified team member from our data entry team will add the results for you. We support various file types, including PDFs, JPGs, or Excel. This service is particularly useful if you have many reports to upload or if you're too busy to handle the data entry yourself.

Our special data entry service makes it easy to add your results to your private dashboard. Just attach an image or a file of your lab test results, and our skilled data entry team will do the work for you. It's all done by humans, ensuring that your data is entered accurately and with personal care for each client.

Depending on your account, the data entry service can be included for free or come at an additional cost of $15 per report.

For users on the Complete monthly plan, the first report is entered free of charge, and each additional report incurs a fee of $15.

Unlimited account holders enjoy the entry of ten reports without charge. Subsequent reports are subject to a $15 fee per report.

Additionally, users on the Complete plan can upgrade to a yearly subscription from the account settings. The annual subscription includes a data entry service for five reports.

The Unlimited plan is a one-time purchase for $250, and it covers your account for a lifetime with no additional payments.

For the Complete plan, the cost is $15 per month. You have the flexibility to cancel it anytime through your account settings, ensuring no further payments. To avoid charges, remember to cancel at least a day before the renewal date. Once canceled, the subscription remains active until the end of the current billing cycle.

Additionally, you can upgrade to the yearly Advanced plan from within your account. The annual cost is $79, and it comes with a data entry service for five reports.

You can always upgrade to a lifetime version with a prorated price from a monthly or yearly subscription.

Simply log in and navigate to your account settings to cancel your subscription. Scroll down to locate the 'Cancel' button at the bottom of the page. Ensure you cancel at least one day before the renewal date to prevent any charges. Once cancellation is requested, the subscription remains active until the conclusion of the current billing cycle.

Unlocking the insights from your lab tests has never been this intuitive! We've crafted multiple ways for you to navigate your data, whether you're glancing at a single report or delving into a treasure trove of testing data.

1. Graph View:

Dive into a visual journey with our biomarker graphs, showcasing over 40 data points. Combining years of results unveils trends, empowering you to make informed decisions. Our visualization tools make it a breeze to compare and understand changes over time, even if your results are from different labs. A search function and filters simplify the exploration of extensive data, allowing you to focus on what needs attention.

2. All Tests View

Get a quick grasp of your test reports in minutes! Explore neatly organized reports on a timeline, highlighting crucial details like dates, critical results, and lab/panel names. Each report opens up to reveal in-depth descriptions and additional recommendations for each biomarker. The history of previous results is just a click away, and you can download a comprehensive report for deeper insights. Color-coded and user-friendly, it's designed for easy reading, understanding, and navigation.

3. Table View:

For a holistic view of all biomarkers side by side, our table view is your go-to. Results are neatly displayed in a categorized and dated table, ideal for those with an extensive test history. Utilize sorting, filters, and color-coding to enhance your analysis and gain extra insights.

Experience the power of clear, organized data visualization with — your key to understanding and taking charge of your health journey!

Yes, you can download information from your account. We can compile your labs into a CSV file. To download all your labs, you can go to Account Settings, and at the bottom of the page, you will find a link to download your information.

Yes, you can print your report. To do so, navigate to "All tests" and open the report you wish to print. You'll find a print button in the right corner of the report. Click on it, and your browser's print window will open. If you prefer to print in a bigger typeface, adjust the scale using the print window settings.

A personal account is all about keeping your own lab test results in check. It's just for you and your personal use.

The professional or business account is designed for health professionals who wish to track and organize their clients' laboratory results.

Use promo code to save 10% off any plan.

We implement proven measures to keep your data safe.

At HealthMatters, we're committed to maintaining the security and confidentiality of your personal information. We've put industry-leading security standards in place to help protect against the loss, misuse, or alteration of the information under our control. We use procedural, physical, and electronic security methods designed to prevent unauthorized people from getting access to this information. Our internal code of conduct adds additional privacy protection. All data is backed up multiple times a day and encrypted using SSL certificates. See our Privacy Policy for more details.