• Thyroid-related symptoms: fatigue, low stamina or feeling cold.
• Cognitive symptoms: brain fog, reduced concentration or memory lapses.
• Weight changes: unexplained weight gain or difficulty managing weight.
• Mood symptoms: low mood, anxiety or reduced motivation.
• Hair and skin changes: thinning hair, dry skin or brittle nails.
• Temperature regulation: sensitivity to cold or changes in body temperature.
• Metabolic concerns: sluggish metabolism or reduced energy output.
• Nutrient considerations: suspected low iodine intake or dietary imbalance.
• Inconclusive blood results: ongoing symptoms despite unremarkable blood thyroid markers.

The Urine Thyroid Hormones (T3/T4) & Iodine (G) test measures urinary triiodothyronine (T3), thyroxine (T4), the T4/T3 ratio and iodine from a 24-hour urine collection. This approach captures thyroid hormone excretion and iodine status over an extended period rather than at a single time point.

This test may be clinically useful when thyroid-related symptoms persist and there is interest in understanding longer-term tissue exposure to thyroid hormones alongside iodine status. Urine-based assessment can add context to standard blood thyroid markers by offering a complementary view of thyroid hormone handling across the day.

Practitioners typically interpret results alongside symptom history, body temperature patterns, dietary iodine intake, medication and supplement use, and other thyroid-related laboratory findings. Considering these factors together supports informed discussions with clients about thyroid-related patterns.

Specimen

Urine (FROZEN) - 24h collection must be made on a Sunday so the frozen urine sample can be shipped on Monday.

If not possible, sample collection can be done on Monday to be shipped frozen on Tuesday latest.

Container

• White capped vial

Patient preparation

• It is essential to avoid excessive fluid intake for the duration of collection. Aim to drink no more than an average fluid intake of 1.5 litres, spread throughout this time.
  
• Discontinue all non-essential medications and dietary supplements, unless instructed otherwise by your practitioner.
  
• Certain medicines may impact test results [e.g. cephalosporins, cimetidine (Tagamet), fibrates (e.g. Ciprofibrate) and trimethoprim-sulfamethoxazole]. Let your practitioner know about your use of these medications.