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Best serotonin supplements: Why 5-htp leads the list
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Summary
- 5-htp, tryptophan, St John’s Wort and probiotics are known as the best serotonin supplements. This article explores if they live up to the hype.
- Tryptophan and 5-htp are the only natural serotonin supplements that directly increase serotonin levels.
- St John's Wort’s mechanism is the same as that of the most prescribed antidepressants known as SSRIs, while probiotics have no direct effect on serotonin.
- For mood regulation supplements alone are not enough. Exercising and morning sunlight will support the release of serotonin which lets you experience the benefits.
The search for emotional balance often begins with one question: how do I support my brain's natural chemistry? At the centre of that conversation is a brain messenger, serotonin, that influences mood. A growing body of clinical research points to targeted nutritional supplements that can meaningfully support its levels, each working through a distinct biological mechanism. This article reviews the four best serotonin supplements; 5-htp, tryptophan, St John's Wort, and probiotics, while exploring what the science actually says about natural serotonin supplements, how they work, who they are best suited to, and how they compare.
What are signs of low serotonin?
Low serotonin is most commonly expressed as persistent low mood[1 Trusted Source 2023 - Journal of Clinical Medicine Human study The Effect of Serotonin Transmission on Depressive and Insomnia Symptoms in Inflammatory Bowel Diseases ] . Serotonin acts as a chemical stabiliser throughout the central nervous system. When serotonin availability falls below optimal levels, this balance is disrupted across multiple systems simultaneously. The most clinically recognised presentations include persistent low or depressed mood with pessimistic thinking, and irritability and emotional dysregulation[2 Trusted Source 2002 - Sleep Medicine Reviews Research evaluation Neurobiological bases for the relation between sleep and depression ] .
How to check your serotonin levels? Apart from evaluating mood symptoms that are a consequence of low serotonin, there is no blood or urine test that could directly assess the levels. They only detect the metabolites of this brain chemical which is not an exact indicator. If you feel like your mood is affected, you might want to look at supplementation options that can help you increase your serotonin levels. Whilst you can't ingest serotonin as a compound itself, you can opt for direct precursors that transform into serotonin, compounds that support the amount of serotonin by keeping it available for longer or natural bacteria that were shown to address the symptoms of low mood. Read more about them.
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5-htp
What is the best supplement to increase serotonin?
5-htp is the most direct supplement for raising serotonin in the brain[3 Trusted Source 1998 - Alternative Medicine Review Research evaluation 5-Hydroxytryptophan: a clinically-effective serotonin precursor ] . Serotonin, scientifically known as 5-ht, is converted inside the body via a two-step pathway: the essential amino acid tryptophan is first converted into an intermediate compound called 5-htp, which is then converted into serotonin[3 Trusted Source 1998 - Alternative Medicine Review Research evaluation 5-Hydroxytryptophan: a clinically-effective serotonin precursor ] . When you supplement with 5-htp directly, you bypass the first step in this chain, making more serotonin immediately available to the brain. In a comparison of the two precursor supplements, 5-htp crosses the blood-brain barrier more efficiently and is converted into serotonin more effectively than L-tryptophan[3 Trusted Source 1998 - Alternative Medicine Review Research evaluation 5-Hydroxytryptophan: a clinically-effective serotonin precursor ] . Unlike tryptophan, 5-htp doesn’t need a transporter molecule to travel into the brain after ingestion[3 Trusted Source 1998 - Alternative Medicine Review Research evaluation 5-Hydroxytryptophan: a clinically-effective serotonin precursor ] .
Clinical research supports this as a systematic review suggests 5-htp to be more effective than placebo at doses of 100 to 300 mg per day for moderately depressed mood[4 Trusted Source 2020 - Nutrition Reviews Systematic and meta-analysis Effects of 5-hydroxytryptophan on distinct types of depression: a systematic review and meta-analysis ] , and in one randomised controlled trial, 63 patients receiving 5-htp 300 mg daily reported improvements equivalent to the antidepressant fluvoxamine 150 mg[5 Trusted Source 1991 - Psychopathology Human study A functional-dimensional approach to depression: serotonin deficiency as a target syndrome in a comparison of 5-hydroxytryptophan and fluvoxamine ] . Is 5-htp the best natural antidepressant? Discover more science behind it, and if you’re interested in testing it yourself, brain feed has developed natural 5-htp with 100mg in one capsule, extracted from Ghanaian-sourced Griffonia seeds.
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Tryptophan
As explained above, tryptophan is the first step in the serotonin conversion pathway. Under optimal conditions, only around 5% of a supplemental dose of L-tryptophan is ultimately converted into brain serotonin, largely because much of it is diverted into other metabolic pathways in the liver before it can reach the central nervous system[6 Trusted Source 2026 - Nutrients Research evaluation Serotonin, Kynurenine, and Indole Pathways of Tryptophan Metabolism in Humans in Health and Disease ] .
Nonetheless, tryptophan was studied for its own role: early tryptophan evidence suggests combining tryptophan with bright morning light therapy produces additive benefits in people with seasonal mood changes[7 Trusted Source 1997 - Canadian Journal of Psychiatry Human study L-tryptophan augmentation of light therapy in patients with seasonal affective disorder ] . However, doses need to be extremely high for these effects to take place. Both precursors are considered the best supplements for serotonin and they directly increase serotonin levels, making them mechanistically different from St John's Wort or SSRIs, which increase serotonin availability by slowing its removal.
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St John’s Wort
How can I increase my serotonin levels fast?
St John's Wort can elevate available serotonin relatively quickly by reducing reuptake. Rather than manufacturing more serotonin, the active ingredient in it, called hyperforin, keeps the serotonin already released in gaps between nerve cells active for longer[8 Trusted Source 1999 - The Journal of Pharmacology and Experimental Therapeutics Animal study Hyperforin, a major antidepressant constituent of St. John's Wort, inhibits serotonin uptake by elevating free intracellular Na+1 ] . This process is called reuptake inhibition, preventing the chemical from being transported back into the neuron that released it. It is the same principle used by the most widely prescribed antidepressant class, selective serotonin reuptake inhibitors (SSRIs)[9 Trusted Source 1998 - Journal of Affective Disorders Research evaluation Mechanism of action of serotonin selective reuptake inhibitors. Serotonin receptors and pathways mediate therapeutic effects and side effects ] .
A review noted that St John's Wort administration upregulates serotonin 5-ht2 receptors in the frontal part of the brain, suggesting it simultaneously enhances sensitivity to the serotonin that is present[10 Trusted Source 2003 - CNS Drugs Research evaluation Mechanism of action of St John's wort in depression : what is known? ] . Clinically, St John's Wort has been suggested to be superior to placebo and equivalent to standard antidepressants for mild to moderate depression in multiple studies[11 Trusted Source 1996 - BMJ Systematic and meta-analysis St John's wort for depression--an overview and meta-analysis of randomised clinical trials ] . Because its action does not depend on synthesising new serotonin, the onset of measurable pharmacological effects may occur more rapidly than with precursor supplements. However, research suggests that full mood stabilisation typically requires several weeks of consistent use, consistent with receptor adaptation timelines, as found in a 6-week randomised control trial[12 Trusted Source 2000 - BMJ Human study Comparison of St John's wort and imipramine for treating depression: randomised controlled trial ] . St John’s Wort is also frequently linked to severe side effects and contradictions with over 800 medications, so caution is needed when supplementing with this nutraceutical. Read more about the comparison between 5-htp, antidepressants & St John’s Wort.
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Probiotics
Where is 90% of serotonin in the body?
Approximately 90–95% of the body’s serotonin is produced and stored in the gut[13 Trusted Source 2017 - Handbook of Experimental Pharmacology Research evaluation Serotonergic Mechanisms Regulating the GI Tract: Experimental Evidence and Therapeutic Relevance ] . However, this serotonin does not cross the blood–brain barrier and therefore does not contribute directly to brain serotonin. While serotonin is often associated with brain function, the gastrointestinal tract is the body’s largest serotonin compartment, where it plays important roles in digestion and gut activity. Specialised cells lining the intestinal wall are the primary serotonin factory, producing and releasing serotonin in response to mechanical pressure (such as food moving through the gut) or other chemical signals after tryptophan is ingested[14 Trusted Source 2022 - Journal of Neurogastroenterology and Motility Research evaluation Enterochromaffin Cells-Gut Microbiota Crosstalk: Underpinning the Symptoms, Pathogenesis, and Pharmacotherapy in Disorders of Gut-Brain Interaction ] . Your body uses less than 3% of food’s tryptophan to make brain serotonin. The rest regulates the wave-like contractions that move food along the gut, stimulates secretion, and acts as a signalling molecule for the gut nervous system[13 Trusted Source 2017 - Handbook of Experimental Pharmacology Research evaluation Serotonergic Mechanisms Regulating the GI Tract: Experimental Evidence and Therapeutic Relevance ] . Read more about the gut and brain connection that supports your mood.
This gut-dominant distribution is why the health of the gut microbiome has direct consequences for serotonin biology. Probiotics work by supporting the gut microbiome. Specific probiotic strains, including Bifidobacterium longum and Lactobacillus strain mix, are suggested to influence depression scores and alter the brain centre for emotional regulation known as the limbic brain activity[15 Trusted Source 2022 - Nutrients Human study Probiotic Mixture Containing Lactobacillus helveticus, Bifidobacterium longum and Lactiplantibacillus plantarum Affects Brain Responses to an Arithmetic Stress Task in Healthy Subjects: A Randomised Clinical Trial and Proof-of-Concept Study ] . However, probiotic effects on brain serotonin in people specifically are indirect, and the magnitude of benefits may be heavily dependent on baseline gut microbiome status, strain selection, and duration. Combining targeted supplementation like 5-htp with gut-supportive probiotics and consistent healthy lifestyle practices represents a holistic strategy for optimising serotonin across both the gut and the brain.
Production VS release: How do I raise my serotonin naturally?
Alongside diet, exercise and sunlight are the most evidence-based lifestyle levers for serotonin. Supplementation is most effective when built on a foundation of lifestyle practices that support the entire serotonergic pathway. Because while tryptophan and 5-htp support serotonin production, the rest support serotonin storage and release. The latter is what helps you feel the benefits of serotonin production.
For example, regular exercise has been suggested to upregulate serotonin receptor expression and activation, and has increased serotonin activity[16 Trusted Source 2001 - Amino Acids Research evaluation Influence of exercise on serotonergic neuromodulation in the brain ] ,[17 Trusted Source 2014 - Applied Physiology, Nutrition, and Metabolism Human study Changes in markers of brain serotonin activity in response to chronic exercise in senior men ] . Finally, bright light exposure, particularly morning sunlight, activates retinal pathways that increase serotonin synthesis in the brain's primary serotonin-producing clusters called the raphe nuclei[18 Trusted Source 2002 - The Lancet Human study Effect of sunlight and season on serotonin turnover in the brain ]. Learn more on how to increase serotonin naturally.
Supporting serotonin is a two-part equation: targeted precursors like 5-htp lay the biochemical groundwork for production, while lifestyle practices drive the release that translates that production into real, felt benefits.
References
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