Thyroid Function Testing
Your thyroid governs metabolism, energy, mood, weight, temperature and much more - and thyroid problems are common, especially in women. Whether you're investigating fatigue, unexplained weight changes, hair loss or mood shifts, or you want to monitor a known thyroid condition, our thyroid tests measure the full picture from a simple TSH check to a complete panel with antibodies. Read 8 signs your thyroid may be the problem. Order online, no GP referral needed.
Want to check your thyroid function?
A thyroid function test measures TSH, free T3 and free T4 - the core markers that show whether your thyroid is underactive, overactive or working normally. It's the usual starting point when investigating fatigue, weight changes or mood symptoms.
1 in 7 individuals live with a thyroid condition with symptoms ranging from low energy and depression to unexplained weight gain and insomnia. If you don’t feel right but you can’t put your finger on why, this simple thyroid test can tell you if it's your thyroid.
If you’re looking for a comprehensive assessment of your thyroid function, including an investigation of an underlying autoimmune disorder, then this combined thyroid antibodies test and thyroid function test is the blood test for you.
Could it be Hashimoto's or an autoimmune thyroid condition?
Many thyroid problems are autoimmune - Hashimoto's (underactive) and Graves' (overactive) involve the immune system attacking the thyroid. Thyroid antibody testing helps identify whether an autoimmune process is involved, which matters for how a condition is monitored. Discuss results with your GP. For the broader picture, explore our immunity & autoimmunity testing.
1 in 7 individuals live with a thyroid condition with symptoms ranging from low energy and depression to unexplained weight gain and insomnia. If you don’t feel right but you can’t put your finger on why, this simple thyroid test can tell you if it's your thyroid.
If you’re looking for a comprehensive assessment of your thyroid function, including an investigation of an underlying autoimmune disorder, then this combined thyroid antibodies test and thyroid function test is the blood test for you.
Is your thyroid getting the nutrients it needs to work?
Your thyroid can't make or activate its hormones without the right raw materials. Iodine is the backbone of the hormone itself, while selenium, zinc and copper drive how it converts and regulates. Getting these wrong - too little, or with iodine too much - can quietly undermine thyroid function even when standard tests look normal. Testing your cofactors shows whether the supporting nutrients are in the right range, so any correction is targeted rather than guessed. Discuss results with your practitioner, particularly before supplementing iodine.
1 in 7 individuals live with a thyroid condition with symptoms ranging from low energy and depression to unexplained weight gain and insomnia. If you don’t feel right but you can’t put your finger on why, this simple thyroid test can tell you if it's your thyroid.
An iodine loading test, also known as an iodine challenge test, is used to determine how effectively the body absorbs and uses iodine. The iodine loading test can be useful in assessing iodine deficiency.
Iron deficiency is the most common nutritional problem in the UK. A shortage of iron leads to anaemia and feelings of weakness, tiredness and dizziness.
Is your thyroid affecting your cycles, fertility or weight?
Thyroid hormones strongly influence menstrual cycles, fertility, mood and metabolism. If you're investigating these, our thyroid tests pair well with focused women's health & fertility testing or weight & metabolism testing.
1 in 7 individuals live with a thyroid condition with symptoms ranging from low energy and depression to unexplained weight gain and insomnia. If you don’t feel right but you can’t put your finger on why, this simple thyroid test can tell you if it's your thyroid.
If you’re looking for a comprehensive assessment of your thyroid function, including an investigation of an underlying autoimmune disorder, then this combined thyroid antibodies test and thyroid function test is the blood test for you.
How i-screen works
01Order online
Choose your preferred blood test and place your order securely through our website.
02Receive pathology request form
We'll email you your pathology request form, which you'll need for your blood draw.
03Book an appointment
Book an appointment for your blood draw at a convenient time and location.
04Get your results
Your results land in your secure dashboard with plain-English explanations from our health team, typically within 2–3 weeks.
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