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5-HTPEvidence & Dosage

Serotonin precursor, mood, and Carbidopa safety.

Studies last updated

Evidence at a glance

Total studies
1,000
With abstract
48
Meta / Systematic / RCT
128
Highly cited
50
Publication years
1954–2026

5-HTP in the context of Mental

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Top studies on 5-HTP

Ranked by influential-citation count and publication year.

  1. 5-Hydroxytryptophan (5-HTP): Natural Occurrence, Analysis, Biosynthesis, Biotechnology, Physiology and Toxicology.

    202096 influential citations

    L-5-hydroxytryptophan (5-HTP) is both a drug and a natural component of some dietary supplements. 5-HTP is produced from tryptophan by tryptophan hydroxylase (TPH), which is present in two isoforms (TPH1 and TPH2). Decarboxylation of 5-HTP…

  2. Effects of Serotonin and Slow-Release 5-Hydroxytryptophan on Gastrointestinal Motility in a Mouse Model of Depression.

    Gastroenterology2019other76 influential citations

    BACKGROUND & AIMS: Mood disorders and constipation are often comorbid, yet their shared etiologies have rarely been explored. The neurotransmitter serotonin (5-HT) regulates central nervous system and enteric nervous system (ENS)…

  3. The impact of 5-hydroxytryptophan supplementation on sleep quality and gut microbiota composition in older adults: A randomized controlled trial.

    Clin Nutr2024n=30rct61 influential citations

    BACKGROUND & AIMS: Sleep quality is a pivotal part of health and there is growing evidence on the association between gut microbiota composition and sleep quality. 5-Hydroxytryptophan (5-HTP) is known as a precursor of the sleep…

  4. Clomipramine. An overview of its pharmacological properties and a review of its therapeutic use in obsessive compulsive disorder and panic disorder.

    Drugs1990RCT58 influential citations

    During the 20 years that have elapsed since clomipramine (chlorimipramine) was first marketed, it has become well established in the treatment of depressive illness, particularly treatment-resistant depression. However, in addition to its…

  5. Effect of a serotonin precursor and uptake inhibitor in anxiety disorders; a double-blind comparison of 5-hydroxytryptophan, clomipramine and placebo.

    Int Clin Psychopharmacol1987n=45rct52 influential citations

    A double-blind placebo-controlled study of 5-HTP and clomipramine was carried out on 45 patients suffering from anxiety disorders (DSM-III). Clomipramine has shown to be effective in that it induced significant improvement on all rating…

  6. Effect of 5-hydroxytryptophan on serum cortisol levels in major affective disorders. II. Relation to suicide, psychosis, and depressive symptoms.

    Arch Gen Psychiatry1984n=26Clinical Trial49 influential citations

    Serum cortisol levels were significantly higher after administration of 5-hydroxytryptophan (5-HTP), 200 mg orally, in unmedicated patients with affective disorders than in controls. The magnitude of the serum cortisol increase correlated…

  7. The serotonin hypothesis of obsessive compulsive disorder: implications of pharmacologic challenge studies.

    The Journal of clinical psychiatry199248 influential citations

    Demonstration of the efficacy of serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitors such as clomipramine in the treatment of obsessive compulsive disorder has fueled interest in the neurobiological basis of this illness. Results of…

  8. The relationship of serotonin to depression in Parkinson's disease.

    Mov Disord1988Clinical Trial48 influential citations

    We have previously reported a correlation between depression in patients with idiopathic Parkinson's disease and decreased concentrations of the cerebrospinal fluid content of the serotonin metabolite, 5-HIAA. To further examine this…

  9. <i>Lacticaseibacillus rhamnosus</i> KY16 Improves Depression by Promoting Intestinal Secretion of 5-HTP and Altering the Gut Microbiota.

    202448 influential citations

    Increasing research suggests a connection between gut microbiota and depressive disorders. Targeted changes to the intestinal flora may contribute to alleviating anxiety and depression. This study aimed to identify probiotics that could…

  10. Treatment strategy in depression. II. MAO inhibitors in depression resistant to cyclic antidepressants: two controlled crossover studies with tranylcypromine versus L-5-hydroxytryptophan and nomifensine.

    Acta Psychiatr Scand1988n=47Clinical Trial42 influential citations

    Antidepressants are ineffective in about 30% of the patients with major depression. Besides electroconvulsive therapy (ECT) and lithium, MAO inhibitors have been suggested as an alternative in such patients. In 2 controlled, partial…

Frequently asked

What dosage was studied?
• 5-hydroxytryptophan (5-HTP) supplementation (100 mg daily)
Are there safety considerations for 5-HTP?
• Not reported in the abstract. • Adverse effects were mild to moderate and mainly anticholinergic. • Seizure incidence increased with dose: 0.48% at <=250 mg/day. • Seizure incidence increased with dose: 2.1% at >=300 mg/day.

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