🔉 Did tinnitus loudness improve?
None shown.
No human tinnitus data yet.
TRTL-913 (GABA-A modulator) for Tinnitus: What Does the Evidence Show?
Drugs & Pharmacology
Current evidence
A new $106M bet that a GABA-A drug can quiet tinnitus — Phase 2 starts soon; no human tinnitus data yet.
Evidence strength: Weak (1/5) · Tier 3 — experimental/emerging · Evidence independence: Independence unclear.
An oral GABA-A positive allosteric modulator (licensed from Hansoh) being developed for tinnitus by Tortugas Neuroscience, which launched in April 2026 with $106M.
Did tinnitus loudness or distress improve?
🧠 Did tinnitus distress improve?
None shown.
No human tinnitus data yet.
Loudness means the tinnitus percept itself became quieter (psychoacoustic matching or loudness ratings). Distress means questionnaire scores such as THI/TFI, sleep, anxiety or quality of life improved — the sound may be unchanged. A THI/TFI improvement is never evidence the tinnitus got quieter.
How strong is the evidence?
Score 1/5: nothing but mechanism and money so far — which is exactly what the ranking rules say cannot earn a high score.
What the studies found 1 tracked
Pharmacotherapy for subjective tinnitus: network meta-analysis of 60 RCTs
Li P, Che C, Wu Y, et al. · BMJ Open · 2025 · N=60 RCTs · Systematic review + network meta-analysis (>30 drug interventions)
No approved drug exists; 78% of included studies had methodological concerns; evidence quality low to very low. Tentative signals (antioxidants, GABA agonists) are hypothesis-generating only and conflict with Cochrane.
What are the limitations?
- Zero human tinnitus data
- History is against tinnitus drugs: every rigorously placebo-controlled candidate so far has failed
Has the result been independently replicated?
None yet.
What should patients know about safety?
Safety evidence: Not yet assessed. Unknown in tinnitus populations; GABA-A drugs generally carry sedation/dependence considerations.
Is it available?
Regulatory status: Investigational (Phase 2 registered). NCT07777549: Phase 2, N=100, not yet recruiting; estimated completion August 2027. Design note: the only placebo-controlled part is in healthy volunteers. The part in people with tinnitus is open-label (no placebo) and lasts 14 days; its main outcomes are safety measures, with tinnitus questionnaires and loudness ratings as secondary measures. It is a safety and dosing study, so it cannot show whether TRTL-913 reduces tinnitus. One of only two Phase 2+ drug trials with tinnitus as the primary indication.
Availability: Not available — trial only · Europe: Not available · Cost (approx.): N/A
Related clinical trials 1
- TRTL-913 (GABA-A positive allosteric modulator) Phase 2a for tinnitus — Not yet recruiting (est. start Sept 2026)
Tracked trials are research in progress, not recommended treatments.
Related treatments 4
- SPI-1005 (ebselen) — The most advanced drug with a tinnitus-relevant claim — but its trials are in Meniere's disease, and the…
- Intratympanic drug injections — Injections through the eardrum keep failing their controlled tests: the experimental drugs did not beat…
- Off-label oral drugs (antidepressants, benzodiazepines, gabapentin, betahistine) — No drug has an FDA-approved indication for tinnitus — and the systematic reviews say none of the usual…
- Supplements (ginkgo, zinc, melatonin…) — Heavily marketed, repeatedly tested — and rigorous reviews have found no reliable benefit.
Claim checks that mention this treatment
From Tinnitus Claims: Fact vs. Evidence, which checks popular claims against the research. It does not change this treatment’s evidence rating.
Evidence last reviewed: 2026-09-04 · Evidence included through: 2026-09-04 · Confidence: high. Open the interactive evidence profile · How we rate evidence.
This page summarizes published research for education. It is not medical advice; it cannot say what will work for any individual. Discuss treatment decisions with a qualified clinician.