Serotonin is often referred to as the "happiness hormone". In reality, its role is much broader: it acts as an internal regulator that influences our mood, emotional stability, sleep, digestion, and even our perception of the world. True to its holistic approach to well-being as taught by Traditional Chinese Medicine, the Nuence-MTC team provides in this article a shedding light on the conditions that allow this molecule to fully play its role and contribute to lasting emotional balance.

1. Serotonin: a complex regulatory system

From a scientific perspective, serotonin is a neurotransmitter involved in:

• mood modulation

• stress management

• the sleep-wake cycle

• appetite

• digestion

• sensory perception

• mental flexibility

Contrary to popular belief, 95% of the body's serotonin is produced in the gut , not the brain. This means that its balance is highly dependent on our digestive system , our gut microbiota , and our lifestyle.

2. The biological conditions that allow serotonin to fully play its role

Serotonin never acts alone . It depends on a set of internal and external conditions.

Here are the factors scientifically recognized as influencing the production, release, or availability of serotonin:

• Natural light: Daylight stimulates brain circuits involved in serotonin synthesis. A lack of exposure can reduce its activity.

• Sleep: During the day, serotonin helps regulate mood, energy, and concentration. At night, it serves as a precursor to melatonin , which promotes sleep (the sleep hormone).

When sleep is disrupted—difficulty falling asleep, nighttime awakenings, too little sleep—several mechanisms become unbalanced, resulting in a lower quantity Serotonin is available for mood, emotional stability, and daytime energy. This serotonin imbalance itself leads to sleep disruption in a downward spiral if the overall balance is not restored.

• Physical activity: Movement stimulates the release of serotonin and promotes neuronal plasticity. Even a daily walk has a measurable impact.

• Diet: Serotonin is synthesized from tryptophan , an amino acid found in certain foods (see below). But it's not just the presence of tryptophan that matters. Other key factors come into play and also influence its availability ( that is to say the amount actually accessible to produce serotonin). Among these, the carbohydrate/protein balance, the quality of the microbiota, the quality of digestion are of primary importance.

• Genetics and individual sensitivity: Some people naturally have a higher or lower sensitivity to serotonin variations.

• Stress: Chronic stress can disrupt serotonin receptors (like a signal jammer) and alter its regulation. As a result, serotonin circulates less efficiently, its action becomes less fluid, and emotional balance is affected.

In TCM, this corresponds to an impairment of the Shen (spirit) and a disturbance of the Spleen Qi , which further increases sensitivity to stress.

3. Foods naturally rich in tryptophan

Legumes: chickpeas, lentils, white or red beans, soy (tofu, tempeh.

They provide tryptophan but also fibers, which support the microbiota — an essential point for emotional regulation.

Oilseeds and seeds: cashew nuts, almonds, pumpkin seeds, sesame seeds, sunflower seeds.

Rich in minerals and healthy fats, they contribute to a more harmonious digestion.

Whole grains: oats, brown rice, quinoa, buckwheat

They promote a more regular release of energy, which supports emotional balance.

Fermented dairy products: yogurt, kefir (see our previous article on fermented foods).

Their interest lies not only in tryptophan, but also in their positive impact on the microbiota.

Some fruits: banana, pineapple, prunes

They provide carbohydrates which facilitate the body's use of tryptophan.

Dark chocolate: it contains tryptophan but also polyphenols which interact with the microbiota and mood.

4. A holistic approach to emotional balance in TCM

In Traditional Chinese Medicine (TCM): emotional balance depends on the circulation of Qi and the harmony of the following organs:

• The Liver because it regulates emotions and the flow of energy.

• The spleen because it influences digestion and the transformation of nutrients (therefore the microbiota).

• The Heart because it governs the mind (Shen).

Serotonin, as an emotional regulator linked to digestion, sleep, and mental stability, lies at the intersection of these three systems.

Traditional Chinese Medicine (TCM) has offered simple practices for centuries—Qi Gong, acupressure, Tui Na massage, and conscious breathing—that support emotional balance by harmonizing Qi and reconnecting the individual to their natural rhythm. Furthermore, in TCM, each season influences our emotions. Adopting appropriate practices (diet, rhythm, movement) supports overall balance. See our previous articles on the best practices associated with each season.

Conclusion

Serotonin is not the happiness hormone and it is not a miracle cure. It is an indicator of overall balance and a reflection of internal harmony (harmonious digestion, restorative sleep, stress management, regular exercise, healthy relationship with the outside world).

There is no cure for serotonin, but there are balanced environments in which serotonin circulates more freely. This is what the holistic approach of Chinese medicine proposes: supporting the systems ( digestion, respiration, movement, etc.) that allow the body to regulate this messenger itself.

And you, among these teachings, Which ones would you like to incorporate to support your emotional balance: adapting your diet? taking care of your gut microbiota, your sleep? committing to a daily walk?