The effect of tryptophan-supplement intake at breakfast on melatonin secretion at night

The effect of tryptophan-supplement intake at breakfast on melatonin secretion at night - The effect of tryptophan-supplement intake at breakfast on melatonin secretion at night

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

JPRN

Registry ID

JPRN-UMIN000024121

Enrollment

Registered

2016-09-21

Start date

2015-04-08

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy adults

Interventions

Tryptophan-supplement intake at breakfast and bright light exposure during daytime (only 1day) Placebo-supplement intake at breakfast and bright light exposure during daytime (only 1day) Tryptophan-su

Eligibility

Sex/Gender

Male

Inclusion criteria

Inclusion criteria: Healthy adult male

Exclusion criteria

Exclusion criteria: 1. Mental diseases 2. Extreame morningness-type 3. Extreame eveningness-type 4. Sleep disorder 5. Smorker

Design outcomes

Primary

Measure	Time frame
Nocturnal melatonin secretion which is measured immediately after intervention	—

Countries

Japan

Contacts

Public ContactTakeshi Morita

Fukuoka Women's University Graduate School of Health and Environmental Science

morita@fwu.ac.jp092-673-0293

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Jul 3, 2026