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Open WellbeingWhat the studies actually measured

Mood, stress and thinking

5-HTPand Serum cortisol (morning)

Only one source here so far, and it measured higher serum cortisol (morning).

How sure anyone can be

Low certainty, level 2 of 4

Further research is likely to change this.

The numbers reported

No number has been put on this yet. One source recorded only which way the numbers went — for now, that is all we have here.

One source, newest first

What we read is the published abstract, not the full paper, so a blank below may still be printed in the paper itself. A fixed rule worked this out from the source’s own fields. Nobody checked this rating by hand.

  • Randomised trial, 2008 · 15 participants

    Low certainty, level 2 of 4

    Pharmacology of rising oral doses of 5-hydroxytryptophan with carbidopa.

    J Psychopharmacol. 2008;22(4):426-33. doi:10.1177/0269881107082025. PMID:18308795.

    Number reported
    Not in the abstract
    Which way it went
    Higher
    Likely range
    Not in the abstract
    Source’s own words
    no placebo-adjusted difference is reported; the abstract gives only per-arm 4-hour AUC levels (placebo 172.0 nmol/L rising to 387.3 nmol/L at 300 mg)
    Who was studied
    Adult male
    Compared with
    placebo
    Amount taken
    100 to 300 mg single oral dose with carbidopa
    For how long
    1 days
    Disagreement between studies
    Not in the abstract
    Kind of record
    Journal article
    How this rating was reachedstarts at High, 2 steps down: risk of bias and imprecision
    1. Starts at High
    2. Risk of bias brought it down to Moderatethe abstract reports no risk-of-bias or quality appraisal, so study limitations cannot be ruled outNot in the abstract
    3. Imprecision brought it down to Lowthe abstract reports no confidence interval for the estimateNot in the abstract
    4. Ends at Low2 steps down.
    Checked, nothing to step it down for
    indirectness
    Inconsistency
    One study, so there was nothing to disagree

    Imprecision stops at the first check that applies; others may apply too.

    AI review could not confirm it — an AI agent re-read this finding against the saved source and at least one check failed. The batch record names the check and quotes the sentence that caused the doubt. No person read it.

    Read the abstract on PubMed

What is still missing from these readings

  • No number at all, only which way it went.
  • One gives no likely range, so how precise that number is is unknown.

Something nobody wrote down is never a zero and never a guess.

Still to read for 5-HTP

Five of the 15 things on our list for 5-HTP have no reading here yet:

  • Cognitive performance
  • Migraine frequency
  • Migraine intensity
  • Salivary cortisol
  • Sleep quality (subjective)

Still to read means nobody here has got to it, not that it was tried and did nothing or that no research exists. A pairing on no list is not a gap: we never set out to read it.

Read next

This is a library, not advice. No recommendation, no dose, no diagnosis, no ranking. We never ask about your symptoms, and nothing here is tailored to you.