GABA (gamma-Aminobutyric Acid) for Sleep Quality

Verdict: Published with Warning

Across 4 PubMed studies, the evidence for GABA (gamma-Aminobutyric Acid) in Sleep Quality grades Tier C — weak evidence. Effective, but with safety or population caveats.

C 🟠 C Weak Evidence Published with Warning

🔬Why this grade7-layer evidence engine

⚖️

Scoring transparency

All scores computed by a 7-layer evidence engine — fully auditable
Raw score 0.55
D
C
B
A
S
← counter-evidence / ineffectiveeffective / strong evidence →
Final grade
C · Published with Warning
Confidence
85%
Highly consistent evidence
Evidence level
E3
Single high-quality meta-analysis

How strongly each layer supports this effect

lower = less supportive
L1 ExamineGlobal benchmark
0.50
L11 AI re-checkIndependent read
0.50
L5 Clinical bodiesAuthoritative stance
0.55
L2 PubMedPrimary literature
0.60
L3 MechanismPlausibility
0.65
Against Mixed Supports
View the full decision path (audit trail)
  1. compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.551
  2. tier_from_score — 依分數區間映射至 tier letter
  3. apply_hec_rules — 無高階證據可裁決
  4. tier_strict_requirement_check — Tier 條件達標,未降階
  5. detect_disputes — 偵測到 0 個 hard + 1 個 soft dispute
  6. decide_status — 依 tier + dispute 結果決定 status

📄PubMed studies (4)L2 · primary research & systematic reviews

Effects of Oral Gamma-Aminobutyric Acid (GABA) Administration on Stress and Sleep in Humans: A Systematic Review
PMID: 33041752 2020 系統性回顧 n = 14
Finding: Very limited evidence for sleep benefits of oral GABA; 3 trials showed reduced sleep latency, no significant effect on PSQI sleep efficiency.
⚠️ Industry-funded
View on PubMed
Safety and Efficacy of GABA from Fermented Rice Germ in Patients with Insomnia Symptoms: A Randomized, Double-Blind Trial
PMID: 29856155 2018 RCT (double-blind) n = 40
Finding: Sleep latency decreased 13.4 to 5.7 min (p=0.001) and sleep efficacy rose 79.4% to 86.1% (p=0.018) in GABA group.
🟠 Limited quality Effect size: MD -7.7 min sleep latency
View on PubMed
Efficacy and Safety of Low-Dose GABA From Unpolished Rice Germ as a Health Functional Food for Promoting Sleep
PMID: 35796273 2022 RCT (double-blind) n = 50
Finding: Sleep latency decreased within GABA group (9.0 to 4.8 min, p=0.0038) but not significantly vs placebo; sleep efficiency unchanged (p=0.2972).
🟠 Limited quality ⚠️ Industry-funded Effect size: MD -4.2 min sleep latency (within-group)
View on PubMed
Effects of a combination of Poria Cocos, Ziziphus spinose, and GABA on sleep quality and skin health: An RCT
PMID: 38873452 2024 RCT (double-blind) n = 70
Finding: PSQI decreased 59.94% (p<0.001) and total sleep duration rose 12.96% (p=0.006) vs placebo; GABA effect not separable from herbs.
🟠 Limited quality
View on PubMed

🏛️Regulatory & authoritative positionsL4/L5 · FDA / EMA / NIH ODS / Cochrane / Mayo …

L4a US FDA
Cautious
4-AMINOBUTYRIC ACID — CAS Reg. No. 56-12-2; other names GAMMA-AMINOBUTYRIC ACID, GABA; Permitted Technical Effect: FLAVORING AGENT OR ADJUVANT; FEMA No. 4288; FEMA GRAS Publication No. 23; JECFA Flavor No. 1771. source↗
L4d TW TFDA / 衛福部
Neutral
γ-胺基丁酸含量,不得低於20%;其每日食用限量,以γ-胺基丁酸計為100 mg。標示「使用本產品應避免同時飲酒或服用降血壓、鎮靜及癲癇等藥物;孕婦、授乳者、嬰幼兒,須諮詢醫師方可使用」。 source↗
PMID 100% verifiedevery citation checked via NCBI Entrez
🔬4 PubMed studiesindependently re-checked by multiple sub-agents
engine_version: v1.0 claim_id: CLM-COND-sleep-quality-INT-gamma-aminobutyric-acid-001 繁體中文版 →