Blood collection at collection point
- After your order you receive instructions by email
- Make an appointment at a collection point near you
- Blood collection at 1,000+ locations across the Netherlands
Blood collection at collection point
- After your order you receive instructions by email
- Make an appointment at a collection point near you
- Blood collection at 1,000+ locations across the Netherlands
- Receive your results digitally by email
What are Reverse T3 (rT3) and Free T3 (FT3)?
Reverse T3 (rT3) is an inactive form of the thyroid hormone triiodothyronine (T3), produced as a byproduct of the normal metabolism of T3. Free T3 (FT3), in contrast, represents the active form of T3 that is available for use by the body. Together, these biomarkers provide important information about thyroid function and metabolism.
Why should you test Reverse T3 (rT3) and Free T3 (FT3)?
Testing both rT3 and FT3 is useful for a more comprehensive assessment of thyroid function, especially in cases where patients exhibit symptoms of thyroid abnormalities, but standard tests do not offer a clear diagnosis. This test is particularly helpful for distinguishing between different types of thyroid dysfunction and for optimizing treatment.
What does it indicate?
The ratio between rT3 and FT3 helps assess thyroid activity and metabolism. An imbalance may indicate a condition, such as conversion disorder, where the body has difficulty converting T4 to the active form T3, or "Low T3 Syndrome".
What does a high rT3 level or low FT3 level mean?
A high rT3 level combined with a low FT3 level may indicate decreased thyroid function or a body reaction to stress, illness, or malnutrition. This may point to the necessity of further evaluating thyroid function and potentially adjusting the treatment strategy.
What does a low rT3 level or high FT3 level mean?
A low rT3 level together with a high FT3 level may indicate hyperthyroidism or an overactive thyroid. This requires further evaluation and possible adjustment of treatment to normalize thyroid function.
Frequently asked questions
Answers to what people usually want to know.
How does it work from order to result?
After ordering we generate a referral letter and email you the instructions. You pick a collection point yourself and book an appointment there. Blood is drawn at the location, processed at the lab, and your result arrives digitally.
How quickly can I get tested?
Usually very quickly. Collection points typically have slots within a few days, sometimes even same-day. It depends on how busy the location is. For a few specialist analyses we first ship collection materials, which takes a bit longer.
Do I need to book an appointment?
At most collection points yes. Some accept walk-ins. This is clearly indicated per location. You choose the location that works best for you.
