Free T4 and Free T3 (fingerstick)
Free T4 and Free T3; concerning thyroid function.
Fingerstick at home – no collection point needed
How it works
- 01
Receive your fingerstick kit
You receive a fingerstick kit with clear instructions
- 02
Prick & collect
Easily collect a few drops of blood yourself
- 03
Mail back
Return via medical mail to the lab
What is Free T4?
Free T4, also known as thyroxine, is a hormone produced by the thyroid gland. It plays a crucial role in our metabolism and energy balance.
Why should you have Free T4 tested?
Measuring Free T4 is useful for assessing thyroid function. It is especially relevant when experiencing symptoms of an overactive or underactive thyroid, such as unexplained weight change, fatigue, or mood swings.
What does it indicate?
Free T4 levels help in evaluating thyroid function. It provides insight into how well the thyroid gland produces and secretes hormones.
What does a high Free T4 level mean?
A high level of Free T4 may indicate hyperthyroidism, a condition in which the thyroid gland produces too much hormone. This can lead to symptoms such as weight loss, nervousness, and a rapid heartbeat.
What does a low Free T4 level mean?
A low level of Free T4 may indicate hypothyroidism, where the thyroid gland does not produce enough hormone. This can lead to symptoms such as weight gain, fatigue, and cold intolerance.
What is Free T3?
Free T3, or triiodothyronine, is another important hormone produced by the thyroid gland. It is even more active than T4 and has a strong influence on metabolism.
Why should you have Free T3 tested?
Testing for Free T3 is useful for a more in-depth evaluation of thyroid function, especially if symptoms or results from other thyroid function tests are contradictory or unclear.
What does it indicate?
Free T3 levels provide an accurate picture of thyroid activity and are particularly useful in diagnosing hyperthyroidism or in cases where T4 levels are normal but symptoms of a thyroid disorder persist.
What does a high Free T3 level mean?
High levels of Free T3 may indicate hyperthyroidism, which can result in symptoms such as increased heart rate, anxiety, and sleep problems.
What does a low Free T3 level mean?
Low levels of Free T3 may indicate hypothyroidism, with possible symptoms such as fatigue, depression, and a sluggish metabolism.
Strong scientific evidence
This test is included in Dutch healthcare guidelines and is regularly used for its respective indications.
Rationale for this test
Vrij T4 en vrij T3 zijn standaard schildklierhormoontesten die in Nederlandse zorgrichtlijnen worden gebruikt voor het beoordelen van de schildklierfunctie. Deze bepalingen zijn klinisch gevalideerd en worden routinematig ingezet bij verdenking op hyper- of hypothyreoïdie. De klinische betekenis van deze testen is goed onderbouwd binnen de reguliere geneeskunde.
Sources consulted
Dutch clinical guidelines and healthcare organisations
Independent information sources
We recommend consulting these independent sources before ordering a preventive health check.
- Client brochure PGO (NVvPG, September 2023)
Brochure on preventive health checks: careful choice, reliability, pros and cons, checklist.
- RIVM — Health tests
Independent information about preventive health checks from the National Institute for Public Health and the Environment.
- Thuisarts.nl
Reliable patient information about illnesses and complaints from Dutch GPs (NHG).
- Allesovertesten.nl (NVKC)
Public-facing website of the Dutch Society for Clinical Chemistry with explanations of blood tests and laboratory values.
Frequently asked questions
Answers to what people usually want to know.
See fingerstick instructionsFull instructions with visual guidanceHow does the fingerstick test work from A to Z?
After ordering we ship the collection kit to your home. You prick your fingertip, collect a few drops of blood, return it in the envelope, and receive your result digitally by email.
How do I collect my blood sample?
A small prick on your fingertip lets you collect a few drops into a tube. The instructions include step-by-step photos and video, so no guessing required.
When and how do I receive my result?
Usually 2 to 5 working days after the lab receives your sample. You get an email with a link to your digital result, including explanation per value.
What if the collection doesn't work?
Some people find the fingerstick tricky at first. Warm your hands, hang your arm down, and prick the side of the fingertip for better blood flow. If it still doesn't work, get in touch.
How do I return my sample to the lab?
In the included return envelope with free medical shipping. Drop it in the mailbox; the lab processes your sample as soon as it arrives. For some tests it's important to send it the same day — the instructions make this clear.
What if I have questions or something doesn't work?
Feel free to contact us via WhatsApp, email or phone. We're happy to help you before, during or after your test. If the collection doesn't work, we'll arrange a solution or send new materials — no hassle.
Didn't find what you're looking for? Request a custom test
Client experiences
This is why clients choose us
“Hele fijne en snelle service”
Hele fijne en snelle service! Ik contacteerde ze ‘s nachts omdat ik zsm moest bloedprikken, ik kon die ochtend nog terecht en heb dezelfde dag mijn uitslag binnengekregen. Echt top!!
“Bloedcheckup levert”
Waar ziekenhuizen moeilijk doen om checkup te doen , komt Bloedcheckup naar boven drijven als vertrouwde partner op gebied van gezondheid. Ik ben uiterst tevreden met bloed checkup
“Klantenservice was erg behulpzaam in…”
Klantenservice was erg behulpzaam in het beantwoorden van mijn vragen. Ik had ook een extra setje buizen nodig als back-up en dat was geen probleem. Ik had een groot test panel besteld, maar de resultaten waren binnen 1 week binnen. Rapport zag er netjes uit.
“Snelle en goede service”
Je hebt de spullen snel in huis en het is duidelijk wat je daarna moet doen. Ook de uitslag heb je snel in huis, ik dezelfde avond al de eerste uitslagen. Bij een bepaling ging het fout, niet eens door het bedrijf maar door het bloedafname punt en die bepaling kreeg ik gewoon vergoed, ook het geld terug stond erg snel op mijn rekening. Vragen worden ook snel beantwoord dus al met al een positieve ervaring bij Bloedcheckup.nl
“Fijn bedrijf met geweldig veel opties…”
Fijn bedrijf met geweldig veel opties om zelfstandig je gezondheid in het oog te houden, als sporter een must want de dokters hebben toch geen verstand van wat relevant en anders is voor sport. Ook zeer tevreden over Stijn zelf! Aangename kerel en goed bereikbaar voor vragen en hulp tijdens bestellen :D
“My experience was very positive”
My experience was very positive. I needed to pass several very specific tests. They provide 24/7 customer support. They were friendly and prompt.
“Top!”
Snelle en makkelijke afhandeling. Duidelijke instructies en binnen anderhalve dag al resultaat binnen. Top service!
“Amazing service!”
Received a packet with everything needed, went to a walk in clinic (Amsterdam DC Clinic) where my blood was drawn and I was out the door within 5 minutes, and then after posting the samples, received results 2 days later. Results were easy to understand as well. Amazing service, would highly recommend!