Optimal Result: 60 - 125 µg/g.

Serotonin is a key neurotransmitter that is involved in the regulation of sleep, appetite and aggression. Serotonin imbalance is a common contributor to mood problems, and pharmacologic agents that alter serotonin levels are among the most commonly used class of drugs prescribed for anxiety and depression.

High stress, insufficient nutrients, fluctuating hormones and the use of stimulant medications or caffeine can all contribute to the depletion of serotonin over time. When serotonin is out of range, depression, anxiety, worry, obsessive thoughts and behaviors, carbohydrate cravings, PMS, difficulty with pain control, and sleep cycle disturbances can result.

What does it mean if your Serotonin result is too low?

Serotonin is lower than the reference range. Generally regarded as the happiness molecule, serotonin has calming effects and contributes to the feelings of well-being. Serotonin elevates mood, decreases anxiety, appetite, and libido, improves sleep and memory, eases depression, and helps regulate body temperature. Most of serotonin in the human body is produced in the gastrointestinal tract, where it stimulates gut motility.

Symptoms of low serotonin levels:

– Depression / Low mood

– Anxiety

– Sleep difficulties

– Uncontrolled appetite / Carbohydrate cravings

– Headaches

– Hot flashes

– Constipation

When serotonin is low, supplementation with cofactors to promote biosynthesis (e.g. vitamin B6), precursors (tryptophan/5-HTP), L-theanine, and probiotics may be helpful. Additionally, lifestyle modifications, such as regular exposure to bright light, healthy diet, sufficient exercise, and positive self-talk are all effective strategies that result in increased serotonin levels. [L]

What does it mean if your Serotonin result is too high?

Serotonin arises from tryptophan metabolism, and is broken down to 5-hydroxyindole acetic acid (5-HIAA) by monoamine oxidase A (MAO A).

Adequate serotonin levels are necessary to support:

- mood,

- decrease anxiety,

- improve sleep and memory,

- and prevent depression.

Too much serotonin, however, can contribute to undesirable symptoms of:

- agitation,

- restlessness,

- confusion,

- rapid heart rate,

- high blood pressure,

- sweating,

- nausea,

- diarrhea,

- and headaches.

Research on urinary serotonin and 5-HIAA is scarce, however, high plasma levels of both serotonin and 5-HIAA have been reported in patients with depression (Mitani, et. al. 2006). Some studies show that urine and plasma levels of serotonin may correlate (Audhya, et. al. 2012).

High serotonin in the body is commonly associated with changes in gastrointestinal (GI) health resulting from increased numbers of serotonin-producing enterochromaffin cells in response to chemical, mechanical or neurological insults (Manocha, et. al. 2012). Compromised GI health may be a contributing factor to the self-reported symptom of depression (Clapp, et. al. 2017; Mayer, et. al. 2015; Wang and Kasper, 2014).

Medications may also contribute to elevated serotonin levels, these include but are not limited to:

- tryptophan,

- 5HTP,

- monoamine oxidase inhibitors,

- methyldopa,

- morphine,

- and reserpine.

Foods containing high concentrations of tryptophan can elevate urinary serotonin levels; these foods include:

- walnuts

- pineapples,

...and to a lesser extent:

- bananas,

- avocados,

- beans,

- cantaloupe,

- dates,

- eggplant,

- grapefruit,

- kiwi,

- lentils,

- meats,

- plantains,

- seeds,

- tomatoes,

- tuna,

- and turkey.

It is important to note that while these foods may elevate urinary levels of serotonin and are a reflection of their interaction with the GI tract (majority of serotonin is produced in the GI tract), and in this case, food-derived elevated urinary serotonin is not representative of serotonin levels in the brain.

Potenetial treatment considerations:

Consider avoiding foods that raise urine serotonin levels artificially. If symptoms of high serotonin are problematic, consider evaluation of current medication to aid in reducing serotonin levels. Addressing gut health if symptoms are present may be beneficial. Therapeutic strategies that employ vitamin B2 supplementation and/or SAMe may aid to lower serotonin levels by promoting metabolism.

Cofactor support for high serotonin levels:

– copper (with zinc),

– Acetyl Coa,

– SAMe

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