How does serotonin affect our emotions?

Can serotonin help to lift your low mood?

Qualified Life Coach
Ask Marianna

09 March 2018

What is serotonin?

Serotonin is sometimes called the happy chemical because low levels have been linked to depression. However it is a chemical that has a wide variety of functions in the human body as well as its key role in maintaining our mood balance. It is mainly found in the brain, bowels, and blood platelets and it helps regulate the body's sleep-wake cycles and the internal clock. Serotonin is also thought to play a role in appetite, the emotions, and motor, cognitive, and autonomic functions as well as its key role in maintaining mood balance.

Serotonin is created by a biochemical conversion process that combines tryptophan, an essential amino acid, with tryptophan hydroxylase, a chemical reactor. This combination is what makes serotonin.  Tryptophan can’t be produced by the body and so must be consumed through our diet, it is commonly found in foods such as nuts and cheese. Tryptophan deficiency can lead to lower levels of serotonin which, in turn, can result in mood disorders like anxiety or depression.

What does serotonin do in the body?

Serotonin plays a significant role in regulation of mood and cognition and helps to relay messages from one area of the brain to another. Serotonin has a number of important roles in the body including:

• Functioning as a natural mood stabiliser by helping to reduce levels of anxiety and depression

• Helping to heal wounds by the formation of clots. Serotonin is released by platelets when there is a wound, it helps to narrow blood vessels, which reduces blood flow and helps blood clots to form.

• Regulation of bowel function. 90% of the body's serotonin is found in the GI tract, where it regulates bowel function and movements. It also plays a part in reducing appetite while eating.


Low levels of serotonin have been linked with:

Low mood

• Poor memory

• Craving for sweet or starchy foods

Difficulty sleeping

• Low self-esteem

• Anxiety

• Aggression


The exact cause of depression is still unknown to us but one theory claims that it may involve an imbalance of neurotransmitters or hormones in the body i.e. low levels of serotonin. There is an apparent link between the two however it is unclear whether low levels of serotonin contributes to depression or results from it. 

Medication to treat depression such as SSRIs are believed to relieve the symptoms of depression by boosting serotonin levels in the body, but exactly how this works is also unknown. Unfortunately, increasing serotonin levels may not directly improve symptoms of depression. One problem is that, while it is possible to measure serotonin levels in the bloodstream, it is not possible to measure levels in the brain. Therefore, researchers do not know, or as yet fully understand, whether serotonin levels in the bloodstream reflect the serotonin levels in the brain, or if SSRIs can really affect the brain.


There is a saying that the gut is the second brain and it’s not hard to see why some have come to this conclusion! 90% of serotonin production actually occurs in the gastrointestinal tract and a mere 5% of represents central serotonin production. 

For central serotonin production to take place, tryptophan needs to gain access to the central nervous system (CNS) through the blood-brain barrier. However, tryptophan competes for transport with several other amino acids that are essential for brain function. This usually limits the amount of tryptophan available for the production of serotonin synthesis. 

Unfortunately, when it comes to diet, there are no such wonder foods out there that can directly increase your supply of serotonin. However, that being said there are foods and some nutrients that can increase levels of tryptophan, the amino acid from which serotonin is made.

Foods high in tryptophan include: pumpkin seeds, soybeans, lentils and tofu. However, high protein meals can cause levels of both tryptophan and serotonin to actually drop. This is because eating protein-packed meals flood the blood with both tryptophan and its competing amino acids which all fight for entry into the brain. That means only a small amount of tryptophan gets through and as a result serotonin levels don't rise.

However eating a carbohydrate-rich meal triggers your body into releasing insulin. This causes any amino acids in the blood to be absorbed into the body rather than the brain, with the exception of tryptophan. It remains in the bloodstream at high levels following a carbohydrate meal, which means it can freely enter the brain and cause serotonin levels to rise. 


Exercise can do a lot to improve your mood; countless studies have shown that regular exercise can be as effective a treatment for depression as antidepressant medication or psychotherapy. The good news is that you don’t have to work out for weeks on end in order to reap the benefits; recent research has found that just a single 40-minute period of exercise is enough to have an immediate effect on mood. 

However, it still remains unclear why and how exercise has this effect and more research is needed to figure out the mechanics of it all. In comparison to indoor exercise, exercising outdoors increases self-esteem, enthusiasm and pleasure, while lowering tension, depression, and fatigue. Sunlight is thought to help boost serotonin, plus you get the additional benefit of obtaining vitamin D too.


Serotonin also has a role to play in our sleep. High levels of the chemical are associated with being awake and alert whereas, low levels are associated with sleepiness. During deep REM sleep our serotonin system temporarily shuts down with the assistance of melatonin which is responsible for regulating our sleep cycles and promoting sleepiness at night-time.

Are there any herbal remedies that can help me to boost my mood?

When it comes to supporting your mood, at A.Vogel we believe that natural remedies are best. Our herbal remedies are made using ingredients that have been traditionally used and tried and tested for thousands of years and of course advocated by our founder Alfred Vogel. For lifting your mood we’d recommend our Hyperiforce tablets that contain St John’s Wort to help treat low mood and mild anxiety. 


A.Vogel Hyperiforce St John's Wort Tablets used to relieve the symptoms of slightly low mood and mild anxiety, 60 tablets

60 tablets

£ 11.99

find your local stockist

For low mood and anxiety. Made from freshly harvested herbs.
More info

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Here’s what I recommend

As the A. Vogel Mood advisor, I recommend St. John’s wort made from freshly harvested Hypericum, to help with feelings of low mood.

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