The Mystery of Serotonin: Can It Really Make You Happy?

Serotonin is a hormone that many people speak of with great reverence. But most people don’t actually know what it does and why it makes them happy. We’re going to explain in this article exactly what serotonin is, why you need it, and how to make sure your levels stay where they’re supposed to.

what does serotonin do

What is Serotonin?

Serotonin is a hormone. The chemical name is 5-hydroxytryptamine and it is a monoamine neurotransmitter. Biochemically, serotonin is derived from tryptophan, a primary amino acid, and is a precursor to melatonin, among other hormones. It is primarily found in the gastrointestinal tract, blood platelets, and the central nervous system.

Serotonin Function

Serotonin helps to regulate anxiety, happiness, and mood. Low levels of serotonin and other related hormones are believed to be a cause and directly related to mental conditions, such as depression, anxiety, moodiness and chronic diseases like Alzheimer’s and Parkinson’s.

Serotonin also helps regulate our gut digestion. When something does not sit properly on our stomach, serotonin levels are greatly increased. The sudden spike in serotonin levels causes our digestive system to move quickly, which can result in diarrhea. If levels become high enough, we experienced vomiting.

Why Serotonin is So Important?

Aside from being important to regulating our moods, this hormone is responsible for many other functions. Directly related to depression, this hormone is responsible for helping us to sleep properly and wake up properly. When serotonin levels are low, the part of our brain that is responsible for helping us to sleep and wake on proper circadian cycles malfunctions. This is one of the reasons why people on third shift experience depression so fast.  

why is serotonin important infographic

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In our blood, the platelets release serotonin in response to damage. When we experience the wound, like a cut on our hand, the serotonin causes the tiny arteries near the cells to contract. This helps stop excessive blood flow and helps for blood clots, which lead to a scab forming and the healing process. When levels of serotonin are low, it can lead to bleeding disorders and exasperate blood pressure problems. 

The opposite is true as well. When serotonin levels are too high, osteoporosis is a significant risk. Certain studies have shown that excessive intake of serotonin, via supplements, or a hormonal problem that over produces serotonin can make bones weaker

Serotonin Metabolism

Serotonin is produced in the pineal gland as a precursor for the hormone melatonin (N-acetyl-5-methoxytryptamine). Now, stick with us, this is going to get a little scientific. If you think it’s going to go over your head, or you get lost, just get to the next section.

The first step of serotonin synthesis is the conversion of L-tryptophan, the primary amino acid, to 5-hydroxytryptophan by the enzyme L-tryptophan hydroxylase (TPH). The next metabolic step of serotonin (and also norepinephrine or dopamine) is the decarboxylation of 5-hydroxytryptophan (and L-DOPA) by cytosolic enzyme L-aromatic amino acid decarboxylase.

Metabolism is carried out in the outer mitochondrial membrane enzyme monoamine oxidase (MAO), which occurs as two molecular subtypes called MAO-A and MAO-B. You may recognize this from the drugs that are MAOI inhibitors.

Inhibition of MAO-A activity has been linked to the antidepressant properties of a number of drugs known to block the activity of the serotonin receptors.

The MAO converts serotonin to 5-hydroxyindole acetaldehyde, then to 5-hydroxyindole acetic acid as the major metabolite of serotonin. Several of their hormones continue from here, but we’re not going to go into that right now.

Serotonin Structure

The chemical formula is C10H12N2O and its official name is 3-(2-aminoethyl)-1H-indol-5-ol or 5-Hydroxytryptamine. But, serotonin is much easier to say. Here’s an image of what it looks like:

You should also know that you could fit nearly a million of these molecules on the head of a pin.

serotonin molecule

Normal Serotonin Levels

The normal range is 101-283 nanograms per milliliter (ng/mL).

What is optimal for you can vary from this number. Some people will feel perfectly normal and healthy closer to the 101 mark, while other people will feel tired and sluggish. Like we said before, high levels can also cause problems. While some people need the higher number, closer to the 283 mark, other people will experience health problems if they are that high.

One of the ways you can make sure your normal levels stay normal is to talk to your doctor and find out what your levels are when you’re feeling good. That way, if you experience mood changes or depression, you can see how your serotonin levels have varied.

Are Serotonin Levels Genetic?

One of the things that are being thrown around in the media lately is certain conditions are genetic. Everything that happens within our body is genetic. It always has been genetic, and it always will be genetic.

The change in your serotonin levels is a response your body has to what you are doing to it. If you are not experiencing enough sunlight, significant stress, a poor diet, or any of the other numerous factors that can cause depression, your serotonin levels will be low. That is what your body is supposed to do on a genetic level in response to these conditions. By changing the conditions, your body will reverse the serotonin level.

Women tend to have more serotonin problems than men. On a genetic level, women produce a higher level of hormones in their body overall, and because of the menses cycle, the hormones fluctuate on a monthly basis.

But, what about serious problems?

Again, this is genetic. For some reason, your genes are telling your body to not produce proper levels. There are some natural things you can do for this, and there are certain medications that help.

Serotonin vs. Melatonin

These are two different hormones. Serotonin is one of the precursors of melatonin *, so you cannot have melatonin without serotonin. If your levels of serotonin are low, your levels of melatonin will be low. This is why people with depression have difficulty sleeping, melatonin helps us go to sleep.

serotonin and melatonin infographic

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Endorphins vs. Serotonin

Endorphins are a different type of hormone, but they are similar to serotonin. Many of the same metabolic pathways serotonin goes through endorphins also go through. The final factors and the metabolites are very different. You cannot substitute one for the other.

Norepinephrine vs. Serotonin

Norepinephrine, also called noradrenaline or noradrenalin, functions as a hormone and neurotransmitter. The general function of norepinephrine mobilizes the brain and body for action. It’s the rush when you feel scared and can help reverse an anaphylactic allergic episode and stimulate the body when it is dying. Generally, you cannot obtain this without a prescription and it should not be used except in critical, life-saving instances.

Cortisol vs. Serotonin

cortisol molecular structure

Cortisol and serotonin are very different hormones. Serotonin is produced primarily in the gut while cortisol is produced in the adrenals (also known as suprarenal glands or adrenal glands). Serotonin is produced more often during times of peace and calm while cortisol is a direct response to stress. Generally, but not always, when one goes up, the other goes down.

Serotonin vs. Dopamine

Dopamine is metabolized in several areas of the brain, including the substantia nigra and the ventral tegmental area and is released by the hypothalamus. Its primary function is a brain regulating hormone. This differs from serotonin, which is primarily used in the gut and the blood.

They are both associated with depression. However, dopamine is often associated with addiction, like heroin addiction, because many of the addictive properties of drugs stimulate the production of dopamine.

What Does Serotonin in the Brain Do?

Serotonin Side Effects

In itself, serotonin does not produce many side effects. It is a natural substance that the body produces and is required by the body. When serotonin is introduced from the outside, it can produce side effects. Some of the side effects of the supplements can include nausea, vomiting, headaches, fatigue, dizziness, and heart problems. We recommend if you going to supplements with serotonin, you do it under the direction of a physician.

How Serotonin Makes You Happy

In most cases, serotonin doesn’t actually make you happy. It directly influences dopamine, a hormone that makes you feel very good. If you actually look at what serotonin does in the body, it can actually make you feel pretty lousy. It’s one of those hormones that causes us to crave sugar, which can increase weight and the risk of diabetes. This is a pretty lousy effect, but what one that was evolutionarily necessary before grocery stores became normal.

The dopamine is what actually makes you feel good. And as you feel good, you feel happy. Without serotonin, or when serotonin levels are low, dopamine is affected – either good or bad.

chemicals that make you happy infographic

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Serotonin and dopamine levels affect anxiety and can cause depression when not balanced properly.

How Serotonin Affects Behavior

There are many hormones in our body that affect our behavior, however, most are not as drastic as serotonin. Because the majority of serotonin is in our guts, it greatly impacts our hunger levels and what we choose for food. Serotonin directly affects our appetite, causing us to feel full or hungry, although it is not the only hormone to do so.

Serotonin causes the desire for sweets and starches. In the past, when food was scarcer, these types of food meant vitamins, minerals, and energy. They were vital to survival. Today, this biological function works to our detriment, causing us to develop diabetes and weight problems.

They’re also certain clotting factors and brain activities that serotonin can affect. Depression and anxiety are two of the main issues, however, serotonin is not directly responsible, but only the precursor to other hormones that work in the brain.

How Serotonin Affects Sleep

serotonin and sleep

As a precursor to melatonin, serotonin can cause fatigue or insomnia. Melatonin helps us to get a proper nights rest and keeps us asleep. When serotonin levels are low, we can’t produce melatonin correctly. The result is sleeplessness and fatigue.

Serotonin when Pregnant

During pregnancy, most hormones are disrupted. All of them, including serotonin, can spike high or drop to nearly nothing. A healthy diet and proper exercise can eliminate most of these problems.

The biggest issue during pregnancy is that very low levels of serotonin can cause depression, which can affect the oxytocin levels, and the estrogen - progesterone balance. Fluctuating serotonin levels have also been linked to gestational diabetes and birth defects.

Most antidepressants have been approved for use during pregnancy, however, most of them have also been linked to various birth defects and hormonal problems. We recommend that you follow up a healthy diet, one that is composed mostly of vegetables, fruits, and quality meats, and follow some of our recommendations for natural serotonin boosts.

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Serotonin Disorders

Serotonin Depletion

Your hormones are a very delicately balanced system within your body, comprising hundreds of different chemical reactions occurring all the time. As stress, anxiety and the blues show up, your serotonin levels become depressed. Generally, in normal people, these periods are brief and a return to emotions restores the serotonin balance.

When the cycle becomes disrupted, serotonin deficiencies can show up.

In most people, the effects of serotonin deficiency are depression in the mood. Other symptoms can include irritability, fatigue, lack of sleep, and weight gain.

Serotonin Syndrome Symptoms

This is a condition that is caused by too much serotonin in your system. It can be caused by several factors, most of the time precipitated by medications. Symptoms include heavy sweating, high body temperature, headaches, agitation, confusion, increased reflexes, diarrhea, tremor and dilated pupils, but may have other factors too.

serotonin syndrome symptoms

Sometimes, this syndrome is caused by taking serotonin supplements (see the section on side effects).

How to Treat Serotonin Syndrome

In the beginning stages, simply stopping the medication is enough to return your levels to normal. This is what is done in the majority of cases. Sometimes, a brief stay in the hospital will make sure there are no other complications.

In severe cases, a longer stay with a series of serotonin blocking medications is used. Doctors may also use paralyzing agents, blood pressure and heart rate-controlling medications, and fluids to preserve the body from the excess levels.

Once the cause of the serotonin excess is discovered, it can be blocked and a person can live normally.

When is Serotonin Syndrome Fatal?

There have been very few deaths associated with high serotonin levels. Most of the time, people visit the doctor or hospital before the problem becomes too severe. Fortunately, medications can stop the progression and should only be used under strict supervision of a doctor.

Low Serotonin Symptoms

Some of the most common low serotonin symptoms include depression, fatigue, and sleep problems.

Other options include a craving for sweets and starches. When your body takes in sugars, the main component of sweets and starches, it produces insulin. Insulin stimulates the production of serotonin, which is why you get a sugar high and feel happy for a short time after you eat that doughnut.

While depression can leave you feeling like nothing, low serotonin levels could also play a factor in violent outbursts. A sign of low serotonin levels can be extreme mood swings. If you do experience mood swings, you will want to talk to your doctor. Low serotonin levels are not the only cause of this problem, as the fluctuating sugars can cause this as well. It is why we advocate a mood stabilizing lower-carb diet.

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High Serotonin Symptoms

As we mentioned before, high serotonin levels can cause nausea and vomiting. Other symptoms can include confusion, restlessness, and changes in your blood pressure. Severe symptoms can include a headache and dilated pupils. Basically, it is like you are drugged.

Morning Serotonin Highs

In the morning, your body begins producing all of its daytime hormones. Your level of serotonin will be naturally higher after you wake up. You can actually keep this morning serotonin high going as long as possible by reveling in the happy feelings and doing exercise.

The release of endorphins help stimulate the release of serotonin, which is why many doctors are recommending exercise programs to people who are depressed period by combining the high in the morning with exercise, you can stimulate your body to produce normal amounts of serotonin all day long.

Serotonin Toxicity

While it does exist, serotonin toxicity is uncommon. It most often occurs when you take supplements or medications. Your body will try to purge the hormone out of your body by resorting to nausea, headaches, confusion and restlessness.

Serotonin Depression vs. Dopamine Depression

When it comes to symptoms, there’s very little difference between a serotonin deficiency depression and a dopamine deficiency depression. The biggest difference is that a serotonin deficiency depression has more fluctuation, while dopamine deficiency depression is characterized by a lack of motivation. Unfortunately, it’s very difficult to tell the difference.

It will be up to your doctor to test for low serotonin levels and low dopamine levels.

five biotypes of depression infographic

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How Do I Know I Have Low Serotonin?

Why Test Serotonin Levels

The best reason to test for your levels is to know how much to supplement. When you take supplements, you don’t want to take too much. As we stated before, too much serotonin puts you at risk for osteoporosis.

If you take too little serotonin supplements, you might not get the results you were looking for. This is also why we recommended checking your normal levels, it will tell you just how much you need to supplement to get back to a normal range.

Who Tests Serotonin Levels

A serotonin test is the only reliable method to know if your levels are low. This test is conducted by your doctor and sent to a qualified medical laboratory.

Although, you can find many quizzes online that will tell you that you have low serotonin. These are not quality or scientific based.

Causes of Low Serotonin

Serotonin and Anxiety

While normal everyday anxiety is not dangerous, prolonged anxiety can cause your serotonin levels to become depressed. As your serotonin levels become depressed, anxiety becomes easier to achieve. It is a vicious cycle that is difficult to break.

There has been some success in using meditative techniques to break the cycle of anxiety, but most of the time medications are used. After several months of taking an antidepressant or anti-anxiety medication, many people recover and are able to return to a normal life.

Serotonin and Sleep

A depression in serotonin can cause sleep problems. Also, a poor sleep schedule can cause depressed serotonin levels.

Our bodies are naturally attuned to the rising and setting of the sun. Waking up too early or going to bed too late causes a disruption of our hormones, particularly in our serotonin levels. It is recommended that you try to sleep as close to the natural circadian rhythm as possible in order to keep your body attuned.

The risk of depression and people who work the overnight shift is high. Because they are sleeping when their body should be awake, their hormone levels are severely impacted. Over time, this causes irritability and depression.

Serotonin and Depression

Depression is a common side effect of low serotonin levels, but it is possible for a period of time that you are down to cause low serotonin levels. One of the ways to avoid this is to keep in touch with friends and family.

Antidepressants and Serotonin

Most antidepressants will not raise your serotonin production levels. What they do is block the uptake of serotonin, so what you naturally produce remains in your system longer. Although it shows the number on a piece of paper is better than it was prior, your actual production levels of serotonin have not increased.

We recommend if you are on antidepressants to read the next section. Combine the medication with natural serotonin boosters so you recover a normal life faster.

Serotonin Boosters

One of the first things you need to do if you want to boost your serotonin levels is to cut out all processed foods. The processing of food depletes it of nutrients and often adds sugars, salts and other chemicals that rob your body of healing factors. Processed foods also denature proteins, so that any tryptophan that is in the food, which is converted to serotonin, is destroyed.

Natural Sources of Serotonin

Food is one of the most natural ways to increase serotonin, and one of the easiest. Many foods contain tryptophan since it’s a basic amino. However, very few foods actually contain serotonin, because it is a hormone.

Natural sources of serotonin and tryptophan are: 


All the current research is showing that eggs are simply perfect. They contain high levels of tryptophan, along with other amino acids, and can really give you a health boost.

eggs for brain infographic

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All meat contain amino acids. Turkey seems to be one of the highest in containing tryptophan but don’t worry, it’s not going to put you to sleep. Just make sure you get local meats that are free of antibiotics, growth hormones, and other chemicals that are found in factory produced meats.


Good quality cheese, coming from cows that are naturally raised without growth hormones or antibiotics contains quality amino acids, calcium, and vitamin D.

cheese tryptophan

Nuts & Seeds

Aside from containing a tremendous amount of healthy fats, all nuts and seeds contain various amino acids and help your body produce quality hormones.

nuts and seeds for brain


Fresh pineapple has a high amount of tryptophan and bromelain. Bromelain is well-known for reducing inflammation. You need to get fresh pineapple. The processing to dehydrated or canning destroy the amino acids.

pineapple serotonin

All Fruits & Vegetables

All fruits and vegetables contain amino acids and in their natural state, are one of the healthiest things you can eat. All of the co-factors, enzymes, vitamins, and minerals that you need to process the tryptophan into the serotonin are contained in vegetables.

tryptophan foods infographic

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Serotonin Diet

We’ve all heard of low-carb dieting, and a diet that helps boost your serotonin is pretty much a lower-carb diet. This is a diet that is about 60g of carbohydrates per day – technically not a low-carb diet nor a high-carb diet. There’s a focus on fruits and vegetables and quality protein. There is a distinct lack of processed foods, sugar, starch and bread. While there’s no one particular food that will give you a tremendous amount of serotonin or tryptophan, a combination of a lot of vegetables will give you all of the nutrients to help process the tryptophan to serotonin properly.

There has been much talk about low-carb diets causing serotonin deficiency. Yes, if you limit your carbs to less than 30 per day, you will depress your serotonin levels. However, this isn’t a license to eat pasta and bread.

Carbohydrates indirectly affect levels of serotonin. Because serotonin is dependent on tryptophan, there is no direct link that shows you will change your levels of serotonin by eating more carbs. Other nutritional variables, such as vitamins, minerals, cofactors, and other phytonutrients, sleep and exercise, influence serotonin production directly.

And here is the best reason to stick to a low-carb diet: …serotonin release is also involved in such functions as sleep onset, pain sensitivity, blood pressure regulation, and control of the mood. Hence many patients learn to overeat carbohydrates (particularly snack foods, like potato chips or pastries, which are rich in carbohydrates and fats) to make themselves feel better. This tendency to use certain foods as though they were drugs is a frequent cause of weight gain, and can also be seen in patients who become fat when exposed to stress, or in women with premenstrual syndrome, or in patients with "winter depression,” Wurtman, RJ et al. Brain serotonin, carbohydrate-craving, obesity and depression. Obesity Research. 1995 Nov;3 Suppl 4:477S-480S.

Basically, if you try to use carbs to stimulate your serotonin production, you tend to overeat and cause the very problems you are trying to avoid. On top of that, now you need to deal with weight gain and diabetes.

Serotonin Herbs

All herbs are highly nutritious and any herb that is listed as a nervine will be particularly helpful in increasing your serotonin levels. One of the most common herbs used for depression is St John’s Wort. It is exceptionally good at helping increase your dopamine and serotonin levels, but you need to be very careful taking it. There are some serious side effects, especially if you are taking medications. If you're interested, you can buy it here *

Other herbs include ginseng  and cannabis. Both of these are well known to help the brain. If you get these extracts, you want to make sure they are quality. You want to make sure the ginseng * is cultivated, and not wild. You also want to make sure the cannabis you take is an extract that does not contain the hallucinogenic factors.

Exercise and Serotonin

Exercise helps produce various hormones associated with feeling good. Endorphins are one of the primary hormones produced, but the body also produces serotonin and dopamine when you exercise. For years, doctors have been recommending exercise to help depression.

This is especially true of the types of depression and anxiety that cause a person to shut themselves in or lack motivation. Exercise is a great way to get out and do things and change the brain chemistry.

chemicals that make you happy infographic

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Serotonin for Weight Loss

Some people recommend the use of serotonin for weight loss. Serotonin is not recommended for weight loss. There are no studies to show it to be effective, and it may not be safe.

A side effect of taking a serotonin supplement may be a reduction in weight. That is because of a reduction in depression which allows the person to move around and be more active. Do not take serotonin for weight loss unless under the direction of a physician.

Medicinal Sources of Serotonin

Most often, doctors will not prescribe serotonin to help cover a serotonin deficiency. Rather, they will prescribe selective serotonin reuptake inhibitors (SSRIs). These serotonin reuptake inhibitors are highly addictive and often come with a host of side effects that are just as bad as the depression. Unfortunately, most doctors will prescribe these antidepressants without testing for serotonin.

We recommend you push your doctor to test for serotonin and dopamine and make sure you are monitored carefully if you choose to take medication.

Are Serotonin Supplements Effective?

Many of the supplements you’ll find on the market are frauds. They contain the very little active ingredient. Quality supplements can be very effective. You just have to do your research and know which kind of supplement you are getting.

Are Serotonin Supplements Safe?

Serotonin supplement can be considered safe as long as you have your doctor’s permission. It is not considered to safe to take supplements on your own unless you know your levels are low.

Where to Buy Serotonin Supplements

Serotonin supplements could be purchased from many sources online. The one thing you want to do is make sure you research the supplement you’re going to take well because many of them are frauds. Generally, a higher price means a better quality supplements, but not always.

If you liked our article, please share it and use the comment section below to tell us about your experiences or ask any questions. Thank You!

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Christina Major

Christina Major is a holistic nutritionist, traditional naturopath, and herbalist. She has a Master’s degree in Holistic Nutrition and an advanced degree in Traditional Naturopathy. Further certifications in herbalism and metabolic typing. She owns and operates Crystal Holistic Health Consulting based in PA, the USA since 2010.
  • Thanks for the artickle. I just needed to understand the interplay all of these hormons. I would like to know how the hormons influence the children with autism and whether these hormons are used in the treatment the childrens. I work in genetics so the area is interesting for me.
    Thanks for answer.

    • Hey, Pavlina!

      Not enough research has been done on the use of hormones to influence behavior in children, especially in the autism spectrum. It’s certainly known that when the hormones are not properly balanced, behavior issues happen.

      Research shows that individuals with autism tend to have unbalanced levels of Serotonin, Dopamine, and Gaba.

      Research also shows that children with autism may have a reduced activity of the serotonin transporter.

      SSRI drugs might be effective at reducing some symptoms of autism by regulating serotonin levels. The medicines do not work for everyone, do have side effects and may stop being effective after a certain time.

      Vitamin D3 is being tested for regulating serotonin levels and shows promise in improving some symptoms of autism.

      The key challenge is identifying a certain chemical as responsible for the symptoms that are specific to autism and not for other conditions.

      We hope if you do any research you will share it with us so we can help more people understand this complex issue as well.

      Thank you!

  • Excellent comprehensive article on serotonin. Throughout the article there is no mention of effect of
    daytime sleep on serotonin. A short nape in noon probably has a beneficial effect on serotonin. Need answer to that also

    • Hey, Rashid!

      Thanks for your comment. We have found some information that shows serotonin levels are boosted by a short daytime nap but can be depressed with longer sleep during the day. We’re going to take a look at this a little bit more and then will expand on the article.

  • This is in essence a good article however it has several errors that mislead. These are partly due to science having moved on since it was written and partly due to language that is a bit misleading. It needs to be updated by a top scientist in the field.

    This is because our early concepts about depression being due to low serotonin levels are now changing and rightly are normalising around dopamine.

    • Hey, BERNARD!

      Thanks for the update, we will be updating our article soon to match current research, and we want to include some of what we will have here.

      Many researchers are linking the partner hormone, dopamine, to depression more than serotonin. We’ll be having a great article on dopamine up soon.

      Serotonin is important to depression, but we’re understanding it is an indirect role, not a primary role. Serotonin affects sleep, levels of dopamine, digestion, and memory. When you sleep poorly, have indigestion or poor gut health, and foggy memories, this triggers depressed dopamine levels and creates foul moods. In addition, many people experience these symptoms during the depression, which signals low levels of serotonin. Some studies have shown people consistently have low levels of serotonin during the depression.

      As we stated in the article, serotonin is one of the dozens of hormones that affect our health. It’s hard to pull out just one and say it’s the cause or cure of everything. If any hormone is off (this includes insulin, diabetics), the other hormones will be off.

  • A very informative article. I was wondering if you have noticed that in B12 deficiency, the levels of serotonin can be markedly increased, 20-40 times higher than normal. Presumably this is due to a build up of serotonin as a precursor to making melatonin. Just wondering if anyone has seen it.

    • Hey Gregory!

      This is an interesting comment and thank you for the compliments. All the studies that we have researched and looked at in response to this comment and over our years as a nutritionist shows that B12 deficiency depresses the production of serotonin. Rather than melatonin, it’s tryptophan that plays the significant role in the production of serotonin. We found no evidence in studies or research that shows a deficiency in B12 can raise serotonin levels. Supplementation of B12 may be helpful in increasing serotonin levels if the origin of the depression is a lack of B12. Otherwise, B12 supplementation will not produce any noticeable change and may cause other health problems.

  • Are the blood test for serotonin (and other neurotransmitter) accurate and reliable? Both my doctor and psychiatrist say there not. Please advise. Thanks.

    • Hey SJH!

      This is a tough question. The test methods for determining serotonin and other neurotransmitters in the blood are accurate as far as the quantity in the blood. However, these numbers say very little about what is happening in the brain. The relationship between neurotransmitters found in the blood and the brain can vary widely in different people. So while the test methods are accurate for what they are, they won’t tell you what is going on in the brain.

  • Yes, an interesting article which confirms to me again: thank God I am a runner! I’m 70, still working, 82cm waist, BMI of 23. And I’ve seen guys my age “give up” because they are “beyond it.” This causes unhappiness and unfitness. Dr. Charles Eugster a bodybuilder at 95 (TED Talks) gives wonderful details in his book too: “Age is Just a Number.” (Amazon).

    • Hey Phillip!

      Congratulations on having good health at 70 years year old! Running is a healthy activity that gets you out and improves your health. Any exercise that raises your heart rate will benefit you. Keep up the good work!

    • Hey Emily!

      Thank you for the compliment. We have an article on dopamine over here. We’re also working on other reports showing the different hormones and how they affect the body, especially when it comes to mental health and how some of these hormones affect our physical health, such as menopause. Stay tuned, and you’ll get your wish.

  • For a low serotonin induced depression patient, should he do exercise every day in the morning or evening? Which is better? Or no big difference?

    • Hey Lin!

      This is a great question. The reason we didn’t cover when to exercise is that it depends on the lifestyle of the person. So far, there’s no conclusive research to show the time of exercise helps people. We recommend fitting in exercise when it is convenient for your schedule and you can do it consistently. It’s more important to keep up a regular program of training than to force yourself into a routine that’s not comfortable.