Believe it or not, serotonin can act as both a neurotransmitter and a hormone in the body. Low levels of serotonin are associated with mood disorders, gut issues, some symptoms of Parkinson’s disease, and other health consequences. Maintaining healthy levels of serotonin can prevent numerous health issues. Read on to learn about all the ways you can boost serotonin levels naturally.
What Does Serotonin Do?
Discovered in the 1940’s, serotonin, 5-hydroxytryptamine or 5-HT, plays pivotal roles in mood, normal body conditions (homeostasis), and gut function. Imbalances in serotonin are linked to a wide array of symptoms that interfere with mental and physical health, impairing quality of life [R, R, R].
What is Serotonin?
Serotonin is an important monoamine neurotransmitter and hormone that acts both on the brain and the gut. Neurotransmitters are messengers released by neurons that communicate with other neurons via electrical signals. Hormones are released by glands and communicate much slower than neurotransmitters.
Serotonin plays a large role in everyday behavior, influencing appetite, emotion, movement, cognition, circadian rhythm, and the “unconscious” nervous system (autonomic). Serotonin is deactivated in the body by specific proteins (reuptake transporters) that take up excess serotonin released in the brain and the gut [R].
In the human body, the majority of serotonin is made, stored, and released by cells in the gut lining (enterochromaffin cells). These cells make serotonin from the amino acid L-tryptophan. Serotonin is secreted into the gut wall, where it can cause digestive tract movements, pain or nausea, widening of blood vessels, and secretion of mucus and fluids. In fact, reduced levels of serotonin are linked to irritable bowel syndrome (IBS) [R, R].
In order for the brain to produce serotonin, 5-hydroxytryptophan or 5-HTP must be transported across the blood-brain barrier. 5-HTP is a by-product of L-tryptophan and also used to make serotonin in the brain [R].
Serotonin helps to maintain mental health. Serotonin is especially low in many mental health disorders such as depression, anxiety, panic, and obsessive compulsions. Sleep problems in people with Parkinson’s disease are also worsened by lower serotonin levels in the brain (including the hypothalamus) [R, R].
Additionally, serotonin connects the gut microbiome with the brain — the “gut-brain interaction.” Decreased diversity and stability of beneficial gut bacteria can cause serotonin-related health issues, especially in the elderly. [R, R].
Specific bacteria in the human digestive tract can boost serotonin production in the gut and in platelets. Gut flora actually balances tryptophan metabolism (via the kynurenine pathway), influencing the amount of L-tryptophan available for making serotonin. [R, R].
Serotonin and Other Neurotransmitters
Monoamine neurotransmitters such as serotonin, norepinephrine, and dopamine together affect mood. A meta-analysis of 90 studies discovered that patients lacking tryptophan, serotonin, or tyrosine experienced low mood [R].
An imbalance in serotonin, dopamine, and norepinephrine may contribute to bipolar disorder. It has been proposed that the combined low levels of these 3 neurotransmitters, and not serotonin alone, cause mood disorders [R].
In the pineal gland, serotonin is used to make melatonin, a hormone that synchronizes the body’s “biological clock,” or circadian rhythm. Low serotonin lowers the amount of melatonin that can be made in the body, interfering with the sleep-wake cycle [R].
40 Ways to Increase Serotonin Naturally
Supplements that Increase Serotonin
In the body, L-tryptophan is used to make 5-HTP from which serotonin is made. Increasing L-tryptophan may raise plasma serotonin, improving cognitive, motor, or gut issues in those who are deficient [R, R].
A protein called alpha-Lactalbumin from milk contains more tryptophan than many other proteins. In a (DB-RCT) study of 18 individuals, 12 grams of alpha-Lactalbumin increased the amount of tryptophan in blood plasma by 16% after 90 minutes [R].
In a pilot study of 13 female patients experiencing premenstrual syndrome (PMS), 6 grams of L-tryptophan taken daily for 14 days improved mood, irritability, difficulty sleeping, and carbohydrate craving [R].
Tryptophan can be purchased as L-tryptophan supplements. 5-HTP (5-hydroxytryptophan) supplements are also available. It is important to note that 5-HTP is not the same as 5-HT, which is the chemical name for serotonin. 5-HTP freely crosses the blood-brain barrier (serotonin itself does not) to be converted into serotonin [R].
In the digestive tract, probiotics restore the gut microbiome and influence the gut-brain interaction. Gut bacteria are important because they can produce tryptophan, from which serotonin is made. Many mental health disorders, such as Parkinson’s disease, are linked to less diverse or fewer gut bacteria [R, R].
In a study ( DB-RTC), an 8-week probiotic regimen (2.0 x 109 CFU/g of Lactobacillus helveticus and 2.0 x 109 CFU/g of Bifidobacterium longum) increased tryptophan levels in 110 individuals with depression. Increased tryptophan can increase serotonin production [R, R].
A probiotic (Bifidobacteria infantis) given to rats for 14 days raised levels of blood tryptophan [R].
3) Vitamin D
Vitamin D helps the body make, release, and use serotonin in the brain only. Vitamin D activates an enzyme that makes serotonin from tryptophan. If vitamin D levels are low, less serotonin can be made in the brain. Thus, increasing vitamin D intake increases serotonin levels, reducing the risk of mental health disorders [R, R].
A cohort study of 9,114 subjects demonstrated that taking vitamin D supplements during the first year of life was correlated with a 77% reduced risk of schizophrenia. In other words, preventing low vitamin D levels early in life may reduce the chance of having schizophrenia later in life [R].
4) Omega-3 Fatty Acids
While vitamin D helps neurons make serotonin, the omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), help neurons release serotonin and improve its activity (increasing serotonin receptor sensitivity). Fish, such as salmon or trout, are high in omega-3 fatty acids. The omega 3 fatty acid supplements are also sold as fish oil capsules [R, R].
Since vitamin D, DHA, and EPA work together to maintain healthy levels of serotonin, inadequate omega-3 fatty acids intake may increase susceptibility to psychiatric illnesses, including depression [R].
In a (DB-RCT) study of 49 patients that repeatedly self-harm themselves, 1.2 grams of EPA and 0.9 grams of DHA capsules daily for 12 weeks reduced suicidal thinking by 45% and depression by 30% [R].
In an observational study of 256,118 Japanese participants, people who ate fish daily had lower rates of suicidal thoughts compared to people who did not eat fish daily. In another observational study of 1,767 Finnish subjects, consuming fish less than twice a week was associated with a higher risk of depression and suicidal thinking [R, R].
Reduced intake of both EPA and DHA by pregnant rats resulted in less production, storage, release, and activity (receptor function) of serotonin in the brains of their offspring. Serotonin was not only reduced in the mothers’ brains but also its availability and production were reduced by (65% and 29%, respectively) in the brains of newborn rats. [R].
5) St. John’s Wort
St. John’s Wort is a popular medicinal plant (Hypericum perforatum) used as an antidepressant for mild depression. The plant appears to increase serotonin in the brain similar to typical antidepressants, but with fewer side effects [R, R].
In a review (of 35 studies) of 6993 patients with depression, St. John’s Wort standalone therapy improved mild to moderate symptoms as well as antidepressants and better than placebo. The typical dose is 300 mg of the extract 3 times per day for at least 4 weeks [R].
6) Vitamin B
In a cohort study, 549 community-dwelling seniors with low vitamin B12 and B9 blood levels were more likely to have irreversible problems with cognition (memory, attention, and thought) [R].
In Rhesus monkeys, a single dose of vitamin B6 increased serotonin production in the brain [R].
The treatment of healthy adult rats with a vitamin B mixture raised serotonin levels in the brain [R].
7) Vitamin C
Vitamin C supplements over a period of 6 weeks increased brain serotonin levels in rats [R].
8) Vitamin E
Vitamin E supplementation for 8 weeks increased serotonin in rats suffering from spinal cord injury [R].
Minerals such as zinc and magnesium may have antidepressant effects. Zinc can be increased through diet in foods such as red meat, oysters, and whole grains. Magnesium is found in green leafy vegetables, nuts, and legumes [R].
In a meta-analysis of 17 observational studies, blood zinc levels were lower in depressed individuals compared to non-depressed individuals. In a study (DB-RCT), 25 mg of elemental zinc supplements daily for 12 weeks reduced depressive symptoms in a study of 20 patients with major depressive disorder [R, R].
Magnesium supplements increase serotonin levels by increasing its availability (reducing reuptake) in the brain. In a (DB-RCT) study, 500 mg of magnesium per day for 8 weeks significantly improved symptoms in 60 patients diagnosed with mild to moderate depression [R].
In healthy rats, long-term administration of zinc increased sensitivity to serotonin in the brain (by increasing the density of serotonin receptors) [R].
Healthy rats with diets lacking magnesium experienced symptoms of depression [R].
Curcumin is the active component of turmeric. In stressed rats, curcumin extended the length of time active serotonin stays in the brain (by blocking the reuptake of serotonin). It also improved cognition and reduced serum corticosterone, or cortisol in the rat [R].
In mice studies, a single dose of curcumin (10-80 mg/kg) increased serotonin levels [R].
11) Velvet Bean
Mucuna pruriens, known as the velvet bean, combats Parkinson’s disease better than the standard treatment (levodopa) in rats with Parkinson’s disease. The long-term use of the powder form of Mucuna pruriens restored serotonin levels in the brain of rats. [R].
L-theanine, an amino acid mostly from tea leaves (e.g. green, black, or oolong tea) and less from Bay Bolete mushrooms, has relaxing effects on the mind. Green tea has the highest concentration of L-theanine [R, R, R].
In a cohort study of 42,093 Japanese individuals, those who consumed at least 5 cups of green tea a day experiences less psychological distress associated with reduced serotonin [R].
In rat studies, L-theanine raised serotonin levels in the brain [R].
Rhodiola rosea is a flowering plant that may help improve anxiety and depression. In a (DB-RCT) clinical trial of 89 patients with mild to moderate depression and low serotonin, Rhodiola rosea extracts (340 mg/day and 680 mg/day) for 42 days improved overall depression, including insomnia and emotional instability [R].
A meta-analysis (5 RCTs) of 177 participants concluded that 30 mg per day of saffron capsules can improve symptoms of depression in adults with major depressive disorder within 6 to 8 weeks [R].
Psychedelics are hallucinogenic drugs such as lysergic acid diethylamide (LSD) and psilocybin mushrooms. Psychedelics can stimulate serotonin activity (by directly binding to serotonergic receptors and also increasing their number), raise serotonin levels, and reduce its breakdown [R].
In a recent pilot study (DB-RCT) of 12 patients with anxiety, 200 μg of LSD significantly reduced self-reported anxiety. LSD was given in a safe psychotherapeutic environment with medical supervision to avoid side effects [R].
In a (DB-RCT) study of 17 healthy individuals, psilocybin (215 micrograms/kg) enhanced mood, increased goal-directed behavior and decreased recognition of negative facial expressions [R].
Though psychedelics can activate serotonin signaling, unsupervised use may lead to serious psychological consequences. Certain plant hallucinogens, as well as synthetic hallucinogens, can be especially toxic [R, R, R, R].
MDMA stimulates the release of serotonin and increases serotonin activity (inhibits reuptake) [R].
In mice studies, MDMA increased serotonin, as well as dopamine, release in the brain [R].
In 5 week (DB-RCT) study involving 40 patients, 50 mg to 300 mg per day improved symptoms of anxiety [R].
18) Magnolia Tree
The bark and seed cones of the Magnolia tree (Magnolia officinalis) appear to have anti-stress, anti-anxiety, and antidepressant effects [R].
Magnolia bark and ginger rhizome are commonly used to treat mental disorders in traditional Chinese medicine (TCM). 30 mg/kg of a magnolia bark and ginger rhizome mixture increased serotonin in the brains of depressed mice [R].
19) Essential Oils
Essential oils are commonly used to reduce anxiety, stress, low mood, and other mental health disorders. Smelling the essential oils (inhalation) can activate pathways in the brain to boost serotonin and dopamine production [R].
In a study of aromatherapy in 60 geriatric patients with depression (RCT), 5 ml of essential oil mixture (containing lavender, sweet orange, bergamot, and almond oil) increased serotonin levels after application two times a week for 8 weeks [R].
Surinam Cherry (Eugenia uniflora) essential oil has antidepressant qualities, as it prolonged the effects of serotonin (by blocking serotonin reuptake) in mice brains [R].
In rats, lavender oil also blocks the breakdown of serotonin, maintaining more serotonin in the blood [R].
20) S-Adenosyl Methionine (SAMe)
SAMe is a naturally occurring compound that plays a role in methylation, energy breakdown and may help patients with major depressive disorder (MDD) who are not responding to conventional, synthetic antidepressants [R, R].
In a (DB-RCT) study involving 73 MDD individuals unresponsive to drug therapy, 800 mg twice a day improved symptoms of depression compared to the placebo [R].
In a (DB-RCT) study of 144 individuals with MDD, 1,600-3,200 mg of SAMe daily for 12 weeks significantly improved mood [R].
Ginseng may act to increase serotonin availability (by reducing reuptake) in the brain. In rats given ginseng extracts, serotonin was made more available in the bloodstream [R].
Valerian may help with irritable bowel syndrome. Interestingly, in a rat study, components of the Valeriani root balanced overactive serotonin in the gut (colon) and serum [R].
Valeriana officinalis root extract reduced breakdown and increased serotonin in regions of the mice brain associated with memory and emotion (hippocampus and amygdala) [R].
In mouse models, passionflower enhances the effects of St. John’s Wort [R].
In mouse models, 20-day treatment with apigenin (10 and 20 mg/kg) increased serotonin levels, cognition, and anxious behavior [R].
Apigenin was able to reduce the impact of chronic mild stress in rats by increasing serotonin availability and reducing its breakdown [R].
Berberine is a salt derived from plants in the Berberis family (the roots, rhizomes, stems, and barks), including barberry, tree turmeric, Oregon-grape, and others. Berberine improves mood by raising serotonin levels and blocking serotonin breakdown [R].
A single berberine dose increased levels of serotonin by 47% in the brains of depressed mice. Long-term treatment with berberine (5 mg/kg for 15 days) increased serotonin by 19% [R].
Mice given berberine in a different study had increased serotonin levels in regions of the brain (hippocampus and frontal cortex) important for memory and mood [R].
Bacopa extract is known for its antipsychotic and nootropic effects. Bacopa extract increased serotonin levels in psychotic mice and improved cognition [R].
Acetyl-L-carnitine (ALCAR) is a modified form of carnitine, a common dietary supplement sold in health food stores. ALCAR protects the brain and may help with depression. In mice, it increased levels of serotonin in the cortex given daily [R].
28) Holy Basil
40 mg/kg of Holy Basil (Ocimum sanctum) increased brain serotonin levels and reduced stress in stressed rats [R].
Lithium has long been used in the treatment of mental disorders such as bipolar disorder. In animal studies, lithium boosts serotonin release from the hippocampus, a crucial part of the brain for memory [R].
Foods That Increase Serotonin
Tryptophan is the amino acid building block for serotonin. Tryptophan is not produced by the body, so it must be taken in through diet. Current research shows that unlike purified tryptophan, consuming tryptophan-rich foods does not necessarily increase brain serotonin [R].
Tryptophan competes with other amino acids for transport across the blood-brain barrier. However, tryptophan-rich diets, such as foods with high-carbohydrate (glycemic) indexes, meats, dairy, fruits, vegetables, and seeds increase levels of tryptophan in the plasma rather than the brain [R].
On the other hand, lack of dietary tryptophan (compared to other amino acids) may lead to lower blood and brain tryptophan levels, decreasing serotonin production. Increased BCAAs also lower tryptophan and serotonin, as well as dopamine in the brain. This may be especially problematic for people who take protein powders to enhance exercise performance [R, R].
Lifestyle Changes to Increase Serotonin
1) Stress Reduction
Cortisol is a hormone released by the body during stress. Cortisol reduces serotonin in the body (by increasing reuptake). Too much cortisol can put individuals at risk for developing mental health disorders. Reducing mental stress may help balance cortisol levels and increase serotonin [R].
High stress, or high cortisol levels, can decrease the amount of serotonin available for use in the body. In studies on human immune and brain cells, cortisol decreased serotonin levels [R].
Many of the lifestyle changes below can be used to decrease stress.
Fatigue as a result of exercise increases the amounts tryptophan that can cross the blood-brain barrier and boosts serotonin production. Psychological benefits of physical exercise can be more readily achieved with consistent aerobic exercise training [R, R, R].
Mice that ran on treadmills had higher levels of serotonin compared to mice that remained inactive. Brain tryptophan remained high even after exercise [R].
3) Yoga and Meditation
213 peer-reviewed RCTs, clinical trials, and meta-analyses suggest that yoga and meditation may help uplift mood and improve symptoms of mild, moderate, and treatment-resistant depression [R].
In fact, meditation activates many parts of the brain important for understanding the self, emotions, problem-solving, adaptability, and increasing awareness. Serotonin plays a role in wakefulness, along with other neurotransmitters, which are all raised in meditators [R, R, R]
In a study (RCT), 28 individuals with mild depression who participated in two 1 hour yoga sessions had enhanced mood compared to the control group [R].
It has been suggested that psychotherapy or counseling can change brain chemistry and even increase serotonin activity (by increasing serotonin receptors). In a (DB-RCT) study of 23 MDD patients who participated in psychotherapy for 4 months, psychotherapy significantly increased serotonin activity and improved symptoms of depression [R, R].
5) Music Therapy
Interestingly, music has been shown to increase neurotransmitters like serotonin. In fact, rats exposed to melodic music (e.g. Mozart’s sonatas) released more serotonin in their brains [R].
6) Dance Therapy
An (RCT) study of 40 students around the age of 16 who participated in dance movement had increased blood serotonin levels compared to the control group [R].
Physical Treatments that Increase Serotonin
Neurofeedback allows individuals to consciously change their brain activity (EEG waves) and therefore modify their behavior and cognition. Some of its clinical uses are for migraines, ADHD, and PTSD [R].
In a study (RCT), neurofeedback (30 minutes, 5 sessions weekly, 4 weeks) was applied to 40 patients with fibromyalgia syndrome (FMS). FMS patients have lower serotonin and widespread pain in their muscles and bones. After 2 weeks, patients experienced less pain, fatigue, anxiety, and depression [R].
Massage therapy decreased cortisol and raised serotonin and dopamine in a broad population with stress-related health problems in 3 studies (review) [R].
In one (RCT) study, 24 adults with low back pain were either given two 30 minute massages per week or subjected to standard relaxation procedures over the span of 5 weeks. Serotonin levels were higher in individuals who received the massage therapy [R].
In a randomized clinical trial, 75 women with fibromyalgia, acupuncture increased levels of serotonin in the serum, compared to placebo[R].
In rats, acupuncture-like stimulation increased serotonin activity in certain regions of the brain [R].
4) Light Therapy
In a study of 25 drug-free hospitalized veterans with MDD or bipolar disorder, bright white light improved depressive symptoms. However, further testing needs to be done on the negative consequences of long-term light treatment [R].
5) Vagus Nerve Stimulation
In rats, sustained vagus nerve stimulation for 14 days also increased the action of serotonin [R].
It is not possible to measure serotonin levels in a human brain without a brain biopsy. Indirect markers that are good indicators of serotonin levels in the brain are cortisol levels and blood or urinary HIAA levels (R, R2).
Risks and Safety
Excess serotonin may result in serotonin syndrome, which can be fatal. Usually, though, serotonin syndrome is a result of drug interactions. No cases have been observed just from safe, natural approaches [R].
MDMA, LSD, and other synthetic drugs may cause serotonin syndrome, and should not be taken without medical supervision or outside a psychotherapeutic environment [R].
Most of the studies mentioned above were performed on adults. More research involving children is needed in order to determine safety.
Abnormally heightened levels of serotonin (hyperserotonemia) is a consistent finding in individuals with autism. Pregnant women with hyperserotonemia are more likely to give birth to children with autism [R, R].
The use of St. John’s Wort or lithium simultaneously with serotonergic drugs like selective serotonin reuptake inhibitors (SSRI), monoamine oxidase inhibitors (MAO-I), and triptans, can increase the risk of serotonin syndrome, a life-threatening and potentially fatal condition [R, R].
Limitations and Caveats
Some of these studies have fairly small sample sizes. Additionally, many of these natural methods of increasing serotonin in the body have only been tested in animals and need further research in humans through clinical trials.
In addition to the concentration of serotonin, both the number of serotonin receptors and their sensitivity may also play an integral role in determining serotonin activity.
Though serotonin is mostly made, stored, and released in the gut, serotonin acts as an important neurotransmitter in the brain. Some of these natural remedies and supplements need further testing to determine if they are able to cross the blood-brain barrier. Long-term application of these remedies should also be further studied.