What does the Serotonin (5-Hydroxytryptamine), Urine test measure?

Why is Serotonin (5-Hydroxytryptamine), Urine measured?

Urinary serotonin is assessed in the Sanesco HP Profile as a marker of peripheral serotonin synthesis capacity, informing decisions about L-tryptophan or 5-HTP precursor support and cofactor sufficiency (B6, iron, zinc, magnesium). In Sanesco's clinical framework, reduced urinary serotonin is associated with depressive symptoms, sleep dysregulation, anxiety, and impaired impulse control, and guides targeted amino acid therapy. Practitioners must communicate to patients that urinary serotonin does not directly measure CNS serotonergic activity — the blood-brain barrier prevents peripheral serotonin from entering the CNS and urinary levels do not validate SSRIs, nor can they diagnose depressive disorder. The clinical utility of this marker lies in nutritional and precursor guidance within an integrative framework.

Reference ranges

Standard reference

# REVIEWER FLAG: Confirm Sanesco reference range for urinary serotonin — Sanesco uses creatinine-corrected reporting for random urine specimens. Reference intervals are proprietary to Sanesco's population dataset and will differ from other laboratories' ranges.

Functional medicine optimal

# REVIEWER FLAG: Confirm whether Sanesco designates an optimal or reference range — Sanesco may report results relative to their proprietary population reference range with low/normal/high categorisation rather than a numerical optimal.

Units

µg/g creatinine

Reference ranges vary by laboratory and assay platform. Interpret in context of the issuing laboratory's stated range.