The Urine Halides (Pre & Post Load) test measures iodine, bromine and fluoride in urine collected before and after administration of an oral iodine or iodide loading dose. A baseline urine sample, typically a first morning void, is collected prior to the load, followed by a timed urine collection after iodine intake. Results are reported relative to creatinine and over the collection period to provide context for halide excretion.
Clinically, this test may be useful when exploring symptoms related to thyroid function, energy regulation, immune response or hormonal balance. Iodine is an essential element involved in thyroid hormone production, while bromide and fluoride are considered antagonistic halides that may influence iodine handling within the body. Comparing pre- and post-load results allows assessment of iodine excretion alongside displacement of other halides.
Practitioners typically interpret results alongside dietary intake, environmental exposure history, medication use and other relevant laboratory findings. When reviewed in context, the test can support informed discussions with clients about iodine status, halide exposure and symptom patterns over time.