Serotonin Deficiency - How to Increase Serotonin Naturally

Serotonin is an important neurotransmitter (brain chemical) that protects us against both depression and anxiety.

Serotonin Deficiency Symptoms

Symptoms of low serotonin levels can include:

  • depression
  • anxiety
  • panic or phobias
  • irritability, impatience
  • perfectionism
  • low self esteem
  • repetitive thoughts
  • suicidal thoughts
  • insomnia
  • sugar cravings
  • PMS
  • muscle pain
  • depression that's worse in winter

Take the serotonin deficiency test to find out if you could be low in serotonin. Or, take our 13 depression tests to find out if you could have one of 13 common causes of depression.

What Causes Low Serotonin Levels?

Serotonin is made in the body from tryptophan, an amino acid found in foods like chicken, beef and cheese. Serotonin levels can be low for a number of reasons, including:

  • not enough protein in the diet - the tryptophan that we need to produce serotonin is found in protein foods, and many people just don't get enough protein in their diets. In addition, a lot of the protein we eat these days is from grain fed animals, and grain fed meat is much lower in tryptophan than grass fed meat. The Mood Cure recommends eating 20-30 grams of protein at each meal - about the amount found in 3 to 4 ounces (around 100 grams) of chicken, fish, red meat or pork (about 6.5 to 8 grams of protein per ounce), 3 eggs (20 grams of protein), 1 cup of cottage cheese (28 grams of protein), or 3/4 cup of almonds (24 grams of protein). See the tryptophan food list.
  • not enough vitamins and minerals in the diet - Calcium, magnesium, Vitamin D and B Vitamins are all involved in the production of serotonin, so even if you have enough tryptophan, a vitamin or mineral deficiency may mean that you can't convert enough tryptophan to serotonin. A healthy diet with plenty of fresh, whole vegetables, fruits and grains is very important for anyone who is low in serotonin.
  • too many "anti-serotonin" foods - caffeine, alcohol and aspartame all inhibit the production of serotonin. Caffeine and alcohol may give you an initial boost, but in the long run they will make your depression worse.
  • too much stress - serotonin is used up quickly when you are under stress and levels can become depleted.
  • not enough light - bright light stimulates the brain's production of serotonin, and people who work indoors or live in cold climates often don't get enough light. The light outside on a sunny day is anywhere from 100 to 1000 times brighter than typical indoor lighting, and even a cloudy day is around 10 times brighter than indoor lighting.
  • not enough exercise - exercise increases serotonin and has been shown to be just as effective as antidepressants in relieving depression - in fact in the long term, its more effective than antidepressants.
  • people who have a condition called pyroluria tend to be low in some of the nutrients needed for serotonin production.

Diagnosis for Low Serotonin

Blood tests and urine tests can be used to measure your amino acid levels, but many physicians are not familiar with their use. Some practitioners say the tests are unreliable and a questionnaire will give a better indication of amino acid levels. If you want to get the testing done, try Googling 'Amino Acid Testing', contact one of the labs that does the testing and ask them to suggest a practitioner in your area who is familiar with the tests. If you can't find a practitioner, some labs let you order the test yourself online.

How to Increase Serotonin Levels Naturally

As well as making sure you have a healthy diet, get enough bright light and a reasonable amount of exercise, there are several supplements that can work wonders for serotonin deficiency depression. If you are taking antidepressants, you have manic-depression or you have a serious physical illness, you should consult a physician before taking any of these supplements.


Our bodies convert the amino acid tryptophan into a substance called 5-HTP which is then converted to serotonin. If you don't have enough tryptophan or if you have a problem converting tryptophan to 5-HTP, a 5-HTP supplement can work wonders, often increasing serotonin levels and lifting depression within half an hour. In one study using 5-HTP to treat 99 patients with deep long term depression (on average they had been depressed for 9 years), almost half completely recovered while others improved significantly. The study's author said "I have never in 20 years used an agent which: (1) was so effective so quickly; (2) restored the patients so completely to the persons they had been and their partners had known; (3) was so entirely without side effects."[1]  

In The Mood Cure, Julia Ross recommends starting with 50 mg capsule of 5-HTP in the mid afternoon, then adding a second if you don't notice much effect within an hour and, if needed, a third if you don't feel like you've improved enough in another hour. Once you've worked out your dose, take this dose every afternoon and again about 9.30 at night if you have trouble sleeping.

Initially the effects of 5-HTP tend to last a few hours then wear off as the serotonin is used up, but over time as you build up your serotonin levels, you should notice a sustained improvement in mood. When you have increased your serotonin levels enough you should be able to reduce your dosage and eventually stop taking it entirely. If you start to feel too relaxed, sleepy or irritable after taking 5-HTP, this is an indication that you are ready to reduce your dose. But keep a bottle on hand in case you need it again in times of high stress.

A few people get stomach aches or other digestive disturbances after taking 5-HTP. If this happens, try taking your 5-HTP with meals or using an enteric coated 5-HTP capsule. The enteric coating means that the capsule will break down in the intestines, not the stomach, and this can prevent stomach aches. If 5-HTP helps initally but after a while makes you feel worse, this usually means your serotonin levels are back to normal and you don't need it any more.

If 5-HTP doesn't work for you or has unpleasant side effects, trytophan and Saint John's Wort both increase serotonin levels and one of these may suit you better.


Tryptophan is the amino-acid that our bodies convert into 5-HTP and then into serotonin. If you have a problem taking 5-HTP, tryptophan may suit you better. In The Mood Cure, Julia Ross recommends starting with 500 mg capsule of tryptophan in the mid afternoon, then adding a second if you don't notice much effect within an hour and, if needed, a third if you don't feel like you've improved enough in another hour. Once you've worked out your dose, take this dose every afternoon and again about 9.30 at night if you have trouble sleeping.

Saint John's Wort

Saint John’s Wort is a herb that increases serotonin naturally. It has been found to be as effective as Prozac [2,3] and has few side effects. If you are unable to take 5-HTP or tryptophan, you might want to try Saint John's Wort instead. Most of the studies on this herb have used a dosage of 300 mg taken 3 times a day.

Increasing your exposure to light

According to Dr Steve Ilardi in The Depression Cure, 15 to 30 minutes of bright sunshine each morning is usually enough to stimulate serotonin production, but if you're not able to get this amount, a lightbox can work wonders. We like the Uplift Technologies DL930 Day-Light Lamp, or if you prefer a smaller, more portable lightbox, the NatureBright SunTouch Plus Lamp. The timing depends on your sleep patterns. According to Dr Ilardi, people who have trouble getting to sleep and find it difficult to get up in the mornings should start off using a lightbox for 30 minutes in the morning, within about an hour of getting up. People who get to sleep OK but wake up too early in the morning should start with 30 minutes in the early evening, about 5 hours before they usually go to bed. People who wake up frequently through the night should start with 30 minutes in the morning, at least half an hour after getting up. People who sleep well but are depressed should start with 30 minutes in the morning, anywhere from half an hour to 2 hours after waking up. If you haven't noticed a difference within a week, try increasing your usage to 60 minutes a day.  


Three sessions of thirty minutes of aerobic exercise a week has been shown to increase serotonin levels and have an antidepressant effect. The most important thing in creating an exercise program that you will stick with is to make it enjoyable - most of us find the thought of 30 minutes on an exercise bike or treadmill pretty uninspiring, but you might find something like bike riding outside, skating, dancing, kayaking, tennis or basketball much more enjoyable. And if you can exercise outside and get some bright light exposure at the same time, even better.


Make sure you take the pyroluria test as pyroluria is a common cause of serotonin deficiency with a different treatment plan.

Other Causes of Depression

Take our 13 depression tests to find out if you could have any of the other common causes of depression.

Where to Find More Information on Low Serotonin

The Mood CureThe Mood Cure: The 4-Step Program to Take Charge of Your Emotions--Today This book has by far the clearest and most detailed information we have found on neurotrasmitter and amino acid deficiencies. It has an excellent chapter on serotonin deficiency with a very comprehensive section on serotonin boosting supplements


The Depression CureThe Depression Cure: The 6-Step Program to Beat Depression without Drugs  This has the best information on using a lightbox that I've found anywhere as well as a very good chapter on exercise.

[1] Van Hiele JJ. "L-5-hydroxytryptophan in depression: The first substitution therapy in psychiatry?"Neuropsychobiology 1980;6:230-40

[2] Brenner R, Azbel V, Madhusoodanan S and Pawlowska M. "Comparison of an extract of hypericum (LI 160) and sertraline in the treatment of depression: A double blind, randomized pilot study." Clin Ther 2000;22:411-19.

[3] Volz HP and Laux P. "Potential treatment for subthreshold and mild depression: A comparison of St John's wort extracts and fluoxetine." Compr Psychiatry 2000 Mar-Apr;41(2 suppl 1):133-37