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Hormones

Serotonin

Serotonin is a neurotransmitter that plays a role in mood, sleep regulation, and digestive function. Maintaining balanced serotonin levels may contribute to emotional stability, restful sleep, and overall quality of life.

Doctor's Assessment Included

Reference Ranges

See the value that applies to you:

Choose male or female — this range differs by sex.

Enter your age — this range changes with age.

This range also depends on context such as cycle phase or sample material; the highlighted rows apply to your group.

Male Your group
umol/l
Low 0.28 Normal 1.14 High
Female Your group
umol/l
Low 0.28 Normal 1.14 High

Reference ranges may vary between laboratories. When you order a test, a BIG-registered doctor assesses your personal results in context. For treatment decisions, discuss your results with your GP.

Check your own value

What It Measures

This test measures the level of serotonin in your blood, reported in umol/l. Blood serotonin levels may reflect overall serotonin production, though they do not directly measure brain serotonin activity. Your healthcare provider can provide context.

Why It Matters

Balanced serotonin levels may support mood stability, healthy sleep patterns, and proper digestive function. Monitoring your levels could help identify potential imbalances early, allowing your healthcare provider to suggest appropriate lifestyle adjustments.

When to Test

Testing may be considered when experiencing persistent mood changes, unexplained sleep disturbances, or digestive irregularities. Some healthcare providers may recommend serotonin testing as part of a broader evaluation of neurotransmitter or hormonal function.

Symptoms

Low Levels

Some people with low serotonin levels may experience low mood, anxiety, difficulty sleeping, increased appetite for carbohydrates, or irritability. Low serotonin could potentially be associated with reduced feelings of well-being over time.

High Levels

Some people with elevated serotonin levels may experience restlessness, rapid heart rate, diarrhea, or muscle twitching. Significantly elevated levels could potentially indicate serotonin syndrome, which requires immediate medical attention.

Lifestyle Tips

Regular physical activity, adequate sunlight exposure, and a balanced diet rich in tryptophan-containing foods may support healthy serotonin levels. Stress management techniques could also be beneficial. Consult your healthcare provider for personalized recommendations.

Frequently Asked Questions

What does a blood serotonin test measure?
A blood serotonin test measures the amount of serotonin circulating in your bloodstream, reported in umol/l. Most blood serotonin is found in platelets. This test may not directly reflect brain serotonin levels, so discuss interpretation with your healthcare provider.
Can diet influence serotonin levels?
Certain foods containing tryptophan, such as turkey, eggs, nuts, and seeds, may support serotonin production. A balanced diet with adequate protein and complex carbohydrates could help maintain healthy levels. Your healthcare provider can offer dietary guidance.
Is serotonin only related to mood?
While serotonin is often associated with mood regulation, it also plays roles in sleep, appetite, digestion, and blood clotting. Approximately 90% of serotonin is produced in the gut, highlighting its broader physiological significance beyond mood.

Tests with related values

These panels measure values from the same category as this marker.

Whoop

A 44-biomarker comprehensive health panel inspired by WHOOP Advanced Labs — a deep look at metabolism, cardiovascular risk, hormones, liver, kidney and inflammation.

SHBG (Sex Hormone Binding Globulin) TSH (Thyroid Stimulating Hormone) ALT (Alanine Aminotransferase) LDL Cholesterol Cortisol DHEA-S Estradiol (E2) Free Testosterone FSH (Follicle Stimulating Hormone) LH (Luteinizing Hormone) Total Testosterone Bicarbonate Calcium Chloride Ferritin Iron (Serum) Magnesium Potassium Sodium Transferrin CRP (C-Reactive Protein) Homocysteine Glucose (Fasting) HbA1c (Glycated Hemoglobin) ApoB (Apolipoprotein B) HDL Cholesterol Omega-3 Index Total Cholesterol Albumin HOMA-IR ALP (Alkaline Phosphatase) AST (Aspartate Aminotransferase) Bilirubin (Total) Total Protein Urea (BUN) Creatinine Vitamin D (25-OH) eGFR (Estimated Glomerular Filtration Rate) Insulin (Fasting) Leukocyte Differential Transferrin Saturation Lipoprotein(a) Triglycerides Basic Blood Count
€499,-

InsideTracker

A 36-biomarker performance and longevity panel inspired by InsideTracker Ultimate — covering heart, hormones, metabolism, inflammation, recovery and iron status.

SHBG (Sex Hormone Binding Globulin) TSH (Thyroid Stimulating Hormone) ALT (Alanine Aminotransferase) LDL Cholesterol GGT (Gamma-Glutamyl Transferase) Cortisol DHEA-S Estradiol (E2) Free Testosterone Total Testosterone Folate (Folic Acid) Vitamin B12 Calcium Ferritin Iron (Serum) Magnesium Magnesium (Intracellular) Potassium Progesterone Sodium Transferrin CRP (C-Reactive Protein) Glucose (Fasting) HbA1c (Glycated Hemoglobin) ApoB (Apolipoprotein B) HDL Cholesterol Total Cholesterol Albumin AST (Aspartate Aminotransferase) Vitamin D (25-OH) Insulin (Fasting) Leukocyte Differential Creatine Kinase (CK) Transferrin Saturation Triglycerides Basic Blood Count
€399,-

Serotonin

€65,-