Product Image

5-HTP 5-Hydroxytryptophan 100 mg

Natural Factors Stress-Relax
4.6
★ ★ ★ ★ ★
(1655 ratings)
5-HTP 100 mg
Product Image
Score79
100 mg of 5-HTP provides standard serotonin-pathway support in a convenient format. The named Griffonia source helps, but missing standardization limits quality detail.
How scoring works
Quantity:60 Tablet(s) • (60 servings)
Goals:
Sleep Support
Mood Support
Weight Loss
Stress Relief

Score 79

100 mg of 5-HTP provides standard serotonin-pathway support in a convenient format. The named Griffonia source helps, but missing standardization limits quality detail.
How scoring works
$20.97($0.34 per serving)
iHerb
$ 20.97
Vitacost
$ 20.97
Amazon
$ 24.99
Report prices

Analysis

A standard 100 mg 5-HTP serving gives the formula a clear and focused role in serotonin-related mood and sleep support. The amount matches the practical middle ground represented in the supplied goal analyses without pushing into a high-strength serving.

Griffonia simplicifolia is identified as the source, although no active standardization percentage is supplied. The tablet(s) format is convenient, but it does not add a disclosed release or absorption feature.

The small calcium addition does not materially broaden the product’s main purpose. Value is reasonable for a focused 5-HTP serving. It best fits adults seeking a straightforward middle-dose option for mood or sleep support.

Who is it for
  • Adults seeking a standard 5-HTP amount
  • People focused on mood or sleep support
  • Users who prefer a simple capsule or tablet routine
Best for
  • Focused serotonin-pathway mood support
  • Indirect sleep support through serotonin and melatonin pathways
  • Stress accompanied by low mood or disrupted sleep

Pros

  • Clearly discloses 100 mg of 5-HTP
  • Tablet(s) format is easy to use
  • Names Griffonia simplicifolia as the botanical source
  • Focused formula is easy to assess

Cons

  • No 5-HTP standardization percentage is provided
  • No controlled-release or enteric delivery feature is disclosed
  • Single-pathway formula offers limited support beyond serotonin production

Warnings

  • Do not combine 5-HTP with SSRIs, SNRIs, MAO inhibitors, tramadol, or other serotonin-raising medicines because serotonin toxicity can occur.
  • The 100 mg 5-HTP serving may cause nausea or digestive upset.
  • Avoid stacking it with other serotonin-focused supplements such as tryptophan or SAMe unless a qualified clinician has reviewed the combination.

Nutrient quality

83 Highest impact

The Griffonia source and time-release design are useful, though extract standardization is absent. The 5-HTP amount matches a common standard serving, while missing extract standardization limits source-potency confidence.

Ingredient transparency

80 Highest impact

Every listed active amount is disclosed, and no proprietary blend hides dosing. Complete directions, inactive ingredients, and some source or standardization details remain unavailable.

Customer satisfaction

68 High impact

The aggregate rating is favorable, and the very large review count makes it stable. No detailed feedback is supplied, so repeated complaints and purpose fit cannot be judged.

Value for money

83 Highest impact

A standard amount and time-release design provide good practical value. Dicalcium phosphate adds little nutritional value, and extract standardization is missing.

Report analysis

Goals

Sleep Support
Impact
Highest effect
B- Goal FitA- Strength of SupportC CoverageA Formula Quality

The time-release caplet supplies a standard, clearly disclosed amount. It provides 100 mg of 5-HTP from Griffonia simplicifolia for a defined sleep-related pathway.

The extract lacks standardization and sleep-specific evidence is less consistent than for direct circadian support. 5-HTP can dangerously raise serotonin activity with SSRIs, MAO inhibitors, or other serotonin-modulating medicines.

Study evidence
5-HTP Supportive 1 study
Mood Support
Impact
High effect
B Goal FitA Strength of SupportC CoverageA- Formula Quality
5-HTP · 100 mg

5-HTP is a direct serotonin precursor with plausible mood relevance, and the 100 mg amount provides a commonly used introductory serving. Human evidence for mood improvement is limited by small and inconsistent trials, so it should not be treated as a substitute for established care.

The Griffonia source and exact active amount are clearly disclosed, while added calcium has no meaningful mood role. Combining 5-HTP with SSRIs, SNRIs, MAO inhibitors, tramadol, or other serotonergic drugs can raise the risk of serotonin toxicity.

Study evidence
5-HTP Supportive 9 studies
Weight Loss
Impact
High effect
C- Goal FitB Strength of SupportD+ CoverageA- Formula Quality

Time-release 5-HTP may support appetite control and carbohydrate-craving management through serotonin production. Evidence for direct weight change is limited, so it is better viewed as situational support than a broad weight-loss formula.

The 100 mg amount is clearly disclosed and the time-release caplet provides a focused delivery approach. People using SSRIs, MAO inhibitors, or other serotonin-raising medicines should avoid combining them with 5-HTP without specific clinical guidance because serotonin can rise too far.

Study evidence
5-HTP Supportive 5 studies
Stress Relief
Impact
High effect
C- Goal FitB Strength of SupportD+ CoverageA- Formula Quality

5-HTP may support emotional well-being through serotonin production, but it is not a direct or reliably proven stress-relief treatment. The 100 mg amount may be more useful for mood or sleep-related stress than for immediate calm.

Griffonia is named as the source, and the time-release format may provide steadier delivery. The extract lacks a standardization percentage, and combining 5-HTP with SSRIs, SNRIs, MAO inhibitors, tramadol, or other serotonin-raising drugs may increase the risk of serotonin toxicity.

Study evidence
5-HTP Supportive 18 studies

Ingredients

IngredientAmount per serving
Calcium (Dicalcium Phosphate)
70 mg
5-HTP (Griffonia simplicifolia)
100 mg
Gluten Free Adults 18–50 Vegan Dairy Free Sugar Free Vegetarian
Report overview
B+ Active Ingredient Quality & BioavailabilityB- Dose, Safety & Label TransparencyC Value

Time-release delivery and the standard target dose make this a practical 5-HTP option. The Griffonia source is disclosed, but the lack of a standardization percentage leaves some uncertainty about extract consistency. The supplied label data do not show a warning for SSRIs or other serotonin-modulating medicines, which matters because combining them with 5-HTP may raise the risk of serotonin toxicity.

Loading alternative details
Report alternatives

Sources

Published studies used for the product analysis and the top-ranked studies for each ingredient and goal.

  1. The Impact of 5-Hydroxytryptophan Supplementation on Cognitive Function and Mood in Singapore Older Adults: A Randomized Controlled Trial.
    Li S; Sutanto CN; Xia X; Kim JE · Nutrients · 2025
    Randomized trial30 participantsMood Support for5-HTP
  2. Comparative study of efficacy of l-5-hydroxytryptophan and fluoxetine in patients presenting with first depressive episode.
    Jangid P; Malik P; Singh P; Sharma M; Gulia AK · Asian journal of psychiatry · 2013
    Randomized trial70 participantsMood Support for5-HTP
  3. Effects of 5-hydroxytryptophan on distinct types of depression: a systematic review and meta-analysis.
    Javelle F; Lampit A; Bloch W; Häussermann P; Johnson SL; Zimmer P · Nutrition reviews · 2020
    Meta-analysis13 studies pooledMood Support for5-HTP
  4. Tryptophan and 5-hydroxytryptophan for depression.
    Shaw K; Turner J; Del Mar C · The Cochrane database of systematic reviews · 2002
    Systematic review64 participants2 studies pooledMood Support for5-HTP
  5. Symptomatic treatment of interferon-α-induced depression in hepatitis C: a systematic review.
    Baraldi S; Hepgul N; Mondelli V; Pariante CM · Journal of clinical psychopharmacology · 2012
    Systematic review64 studies pooledMood Support for5-HTP
  6. The impact of 5-hydroxytryptophan supplementation on sleep quality and gut microbiota composition in older adults: A randomized controlled trial.
    Sutanto CN; Xia X; Heng CW; Tan YS; Lee DPS; Fam J; Kim JE · Clinical nutrition (Edinburgh, Scotland) · 2024
    Randomized trial30 participantsSleep Support for5-HTP
  7. Serotonin precursors in the treatment of depression.
    van Praag HM · Advances in biochemical psychopharmacology · 1982
    Narrative reviewMood Support for5-HTP
  8. 5-Hydroxytryptophan (5-HTP) and a MAOI (nialamide) in the treatment of depressions. A double-blind controlled study.
    Aliño JJ; Gutierrez JL; Iglesias ML · International pharmacopsychiatry · 1976
    Non-randomized trial30 participantsMood Support for5-HTP
  9. Measurement of 5-hydroxyindole compounds during L-5-HTP treatment in depressed patients.
    Takahashi S; Takahashi R; Masumura I; Miike A · Folia psychiatrica et neurologica japonica · 1977
    Single-arm trial14 participantsMood Support for5-HTP
  10. Effect of 5-Hydroxytryptophan on Fatigue in Quiescent Inflammatory Bowel Disease: A Randomized Controlled Trial.
    Truyens M; Lobatón T; Ferrante M; Bossuyt P; Vermeire S; Pouillon L; Dewint P; Cremer A; Peeters H; Lambrecht G; Louis E; Rahier JF; Dewit O; Muls V; Holvoet T; Vandermeulen L; Peeters A; Gonzales GB; Bos S; Laukens D; De Vos M · Gastroenterology · 2022
    Randomized trial166 participantsMood Support for5-HTP
  11. Effect of a serotonin precursor and uptake inhibitor in anxiety disorders; a double-blind comparison of 5-hydroxytryptophan, clomipramine and placebo.
    Kahn RS; Westenberg HG; Verhoeven WM; Gispen-de Wied CC; Kamerbeek WD · International clinical psychopharmacology · 1987
    Randomized trial45 participantsStress Relief for5-HTP
  12. Acute L-5-hydroxytryptophan administration inhibits carbon dioxide-induced panic in panic disorder patients.
    Schruers K; van Diest R; Overbeek T; Griez E · Psychiatry research · 2003
    Randomized trial48 participantsStress Relief for5-HTP
  13. Pharmacology of rising oral doses of 5-hydroxytryptophan with carbidopa.
    Smarius LJ; Jacobs GE; Hoeberechts-Lefrandt DH; de Kam ML; van der Post JP; de Rijk R; van Pelt J; Schoemaker RC; Zitman FG; van Gerven JM; Gijsman HJ · Journal of psychopharmacology (Oxford, England) · 2008
    Randomized trialStress Relief for5-HTP
  14. Enhanced tolerability of the 5-hydroxytryptophane challenge test combined with granisetron.
    Jacobs GE; Kamerling IM; de Kam ML; Derijk RH; van Pelt J; Zitman FG; van Gerven JM · Journal of psychopharmacology (Oxford, England) · 2010
    Randomized trialStress Relief for5-HTP
  15. An open-label trial of L-5-hydroxytryptophan in subjects with romantic stress.
    Emanuele E; Bertona M; Minoretti P; Geroldi D · Neuro endocrinology letters · 2011
    Single-arm trial15 participantsStress Relief for5-HTP
  16. The Effects of 5-HTP on Body Composition: An 8-Week Preliminary RCT.
    Evans C; Mekhail V; Curtis J; Czartoryski P; Kaminski J; Ellerbroek A; Bustillo E; Jiannine L; Santana JC; Antonio J · Journal of dietary supplements · 2023
    Randomized trial48 participantsWeight Loss for5-HTP
  17. Effects of oral 5-hydroxy-tryptophan on energy intake and macronutrient selection in non-insulin dependent diabetic patients.
    Cangiano C; Laviano A; Del Ben M; Preziosa I; Angelico F; Cascino A; Rossi-Fanelli F · International journal of obesity and related metabolic disorders : journal of the International Association for the Study of Obesity · 1998
    Randomized trial25 participantsWeight Loss for5-HTP
  18. The effects of oral 5-hydroxytryptophan administration on feeding behavior in obese adult female subjects.
    Ceci F; Cangiano C; Cairella M; Cascino A; Del Ben M; Muscaritoli M; Sibilia L; Rossi Fanelli F · Journal of neural transmission · 1989
    Clinical trial19 participantsWeight Loss for5-HTP
  19. Serotonergic drugs : effects on appetite expression and use for the treatment of obesity.
    Halford JC; Harrold JA; Boyland EJ; Lawton CL; Blundell JE · Drugs · 2007
    Narrative reviewWeight Loss for5-HTP
  20. Eating behavior and adherence to dietary prescriptions in obese adult subjects treated with 5-hydroxytryptophan.
    Cangiano C; Ceci F; Cascino A; Del Ben M; Laviano A; Muscaritoli M; Antonucci F; Rossi-Fanelli F · The American journal of clinical nutrition · 1992
    Randomized trial20 participantsWeight Loss for5-HTP