Product Details

• Fatigue or low stamina: persistent tiredness, slow recovery or reduced resilience.
• Thyroid-related concerns: experiences associated with altered thyroid hormone patterns under practitioner review.
• Temperature sensitivity: feeling unusually cold or experiencing fluctuating temperature comfort.
• Weight or metabolic changes: difficulty managing weight, slowed metabolism or altered appetite patterns.
• Mood or cognitive concerns: low mood, reduced clarity or difficulty with concentration.
• Stress-related presentations: symptoms emerging during periods of physical, emotional or environmental stress.
• Clients with nutrient considerations: cases where selenium status or other nutritional factors are being explored.
• Monitoring alongside broader thyroid assessment: used with TSH, T4 or T3 markers for contextual interpretation.

The Reverse T3 test measures serum concentrations of reverse triiodothyronine, a metabolite of thyroxine produced through peripheral conversion. Assessing reverse T3 alongside other thyroid markers can help practitioners gain additional context when reviewing thyroid-related hormone patterns.

Clinically, this assessment may be useful when exploring fatigue, temperature sensitivity, weight or metabolic changes, cognitive concerns or presentations linked with stress. Reverse T3 may also be considered in cases where nutritional factors, such as selenium status, are part of a broader thyroid review.

Practitioners typically interpret reverse T3 values together with markers such as TSH, free T4 and free T3, alongside health history, lifestyle, nutrient intake and environmental influences. Used in this way, the Reverse T3 test can support a more comprehensive understanding of thyroid-related patterns for clients.

Practical

Specimen requirements:

Before:
Drugs that may interfere with test results include glucocorticoids (e.g., prednisone), dopamine, lithium,
interferon-alpha, phenobarbital, phenytoin, heparin, clofibrate, carbamazepine, and colestipol. If you have
questions, please contact your healthcare practitioner.  (Do NOT discontinue any medication without consulting your practitioner.)
• Patient must fast for 12 hours prior to blood draw. (Do not eat solid food and drink only water when necessary).
• Please schedule your blood draw for Monday – Wednesday to leave enough time for the sample to reach the
laboratory before the weekend.

After:
• Write patients full name, date of birth, time and date of collection on collection tube.
• Red/grey topped SST and red topped amber transfer tube:
i. Draw the red/grey topped SST fully – must be at least 0.5ml.
ii. Mix blood sample thoroughly by gently inverting the tube 3-5 times. DO NOT SHAKE.
iii. Centrifuge the red/grey topped SST at 1000g for 15 minutes. The serum must be free of
hemolytic or red blood cells. (Centrifuge not needed, if we (at Nordic Labs) have the speciemen within 24 hours of blood draw.)
iv. Pipette all the serum from the red/grey SST into the red topped amber transfer tube.
v. Cap transfer tube tightly and place into the plastic tube holder and seal.
vi. If unable to send immediately, store in a refrigerator to keep specimen stable. DO NOT FREEZE.