The purpose of this study is to investigate the efficacy and safety of dietary supplement GABA in subjects with mild, transient sleep disorder.

The subjects will take GABA or placebo capsule once daily before sleep for 14 days.

Inclusion Criteria:

• Male and female subjects older than 19 years old
• Who is experiencing mild, transient sleep disturbance (pittsburgh sleep quality index ≥ 5, Insomnia Severity Index ≥ 8)
• Who voluntarily agreed to participate in the study and signed an informed consent form.

Exclusion Criteria:

• Who is suffering from severe sleep disorder including sleep disorders due to psychological or neurologic causes.
• Who has used sleeping pills or sleep related dietary supplements within 4 weeks before study participation
• Who is suffering from obstructive sleep apnea.
• Who has used or is expected to inevitably use prohibited concomitant medications during the study.
• Women who is pregnant /breast-feeding, or who has childbearing potential and does not use available contraceptives.
• Who has dosed other study medications within 30 days before screening.
• Who is determined ineligible for study participation by investigators for any other reasons.