Peptides / Brain and mood

Synthetic analog · 2 amino acids · 434.5 Da

GB-115

Approved in Russia

GB-115 (Ranquilon) is a modified dipeptide that acts on the cholecystokinin pathway, studied for anxiety, registered as a medicine in Russia, with no US or EU approval found. Studies in people tested it on anxiety and memory, and tracked side effects. PepBank shows 24 results on GB-115 from 4 studies in people, and 67 from animal and lab studies. The strongest evidence is a randomized trial in people. Data as of 2026-10-30.

Also known as (-)-GB-115, GB 115, GB115, Ranquilon, Ранквилон

2 amino acids, from first to lastGW

Evidence level: Some studies in people24 of 91 results come from studies in people.

Results in people

26% of 91 results

Results in animals

74% of 91 results

Results in lab cells

0% of 91 results

From computer models

0% of 91 results

Overview

GB-115 at a glance

What it is	Synthetic analog, 2 amino acids
Approval	Approved in Russia only
In sport	Status unknown
Studies	21 studies with results. All of them gave GB-115, with 91 results. 24 in people67 in animals
Best study in people	Randomized controlled trial with 200 people (2026)
Clinical trials	2 registered: 1 active or planned, 0 with posted results
Community use	Anxiety in neurasthenia and adjustment disorders in adults aged 18 years or older

The science

What is GB-115?

A modified dipeptide studied as an anxiolytic through the cholecystokinin pathway.

Amino acids in one chain

The history of GB-115

2003
The oldest paper on GB-115 in PepBank is from 2003.
2022October
A registered trial of GB-115 started (NCT05586789).

GB-115 structure and chemistry

The key facts about the molecule. Long codes are in the closed section below.

Sequence, 2 amino acidsFrom the first amino acid to the last

G1W

Darker means more water-repelling+ and − show charge in the bodyOutlined: changed amino acid

Structure

GB-115 is a synthetic analog of 2 amino acids, with no ring, 2 changed amino acids.

Formula

C₂₅H₃₀N₄O₃

Molecular weight

434.5 g/mol

CAS number

678996-63-9

Targets

CCKAR (gene CCKAR): antagonistEvidence: Clinical pilot report describes CCK1 antagonism.CCKBR (gene CCKBR): antagonistEvidence: Animal pharmacology report proposes CCK2 antagonism.

Development

Zakusov Institute of Pharmacology (originator), Valenta Pharm JSC (clinical sponsor and marketer). Highest phase: past the trial stage (see status).

Identifiers

PubChem 11281948, UNII G5YT2F7SG8

Full sequence, SMILES and InChIKey

Three-letter sequence
Gly-Trp

InChIKey
ZBIQNIJICMOVKN-QFIPXVFZSA-N

SMILES
C1=CC=C(C=C1)CCCCCC(=O)NCC(=O)N[C@@H](CC2=CNC3=CC=CC=C32)C(=O)N

See charge, composition and 3D structure on the Scientific page

The evidence

What GB-115 studies show

Results grouped by what the studies measured. Each card shows where its results come from.

Some studies in people24 of 91 results come from studies in people.

Mood, stress and behavior

32 results · 5 in people · 27 animal

In patients with anxiety, all secondary efficacy criteria favored Ranquilon over Afobazol. Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova, 2026

Top results

In patients with anxiety, all secondary efficacy criteria favored Ranquilon over Afobazol. (Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova, 2026)
In MR rats, GB‑115 significantly reduced average daily ethanol consumption. (Bulletin of experimental biology and medicine, 2016)
In patients with generalized anxiety disorder, the study identified 6 mg per day as the effective GB‑115 dose. (Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova, 2019)

Memory and thinking

4 results · 4 in people

In patients with generalized anxiety disorder, GB‑115 treatment was linked to favorable attention, reaction time, and overall performance changes. Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova, 2019

Top results

In patients with generalized anxiety disorder, GB‑115 treatment was linked to favorable attention, reaction time, and overall performance changes. (Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova, 2019)
In patients with generalized anxiety disorder, reaction time decreased versus background during GB‑115 treatment. (European psychiatry, 2022)
In patients with generalized anxiety disorder, attention task times improved versus background during GB‑115 treatment. (European psychiatry, 2022)

Survival and serious illness

3 results · 1 in people · 2 animal

In patients with anxiety, neither Ranquilon nor Afobazol groups reported fatal adverse events. Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova, 2026

Top results

In patients with anxiety, neither Ranquilon nor Afobazol groups reported fatal adverse events. (Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova, 2026)
In mice, no animals died after an acute oral GB‑115 dose of 6000 mg/kg. (Eksperimental'naia i klinicheskaia farmakologiia, 2010)
In rats, no animals died after an acute oral GB‑115 dose of 3500 mg/kg. (Eksperimental'naia i klinicheskaia farmakologiia, 2010)

Daily life and fitness

2 results · 1 in people · 1 animal

In patients with generalized anxiety disorder, fatigue scores decreased from baseline during GB‑115 treatment. European psychiatry, 2022

Top results

In patients with generalized anxiety disorder, fatigue scores decreased from baseline during GB‑115 treatment. (European psychiatry, 2022)
In mice with experimental autoimmune encephalomyelitis, GB‑115 improved spontaneous movement. (Bulletin of experimental biology and medicine, 2011)

Immune system and inflammation

9 results · 9 animal

In animal inflammation models, GB‑115 showed anti-inflammatory effects. Bulletin of experimental biology and medicine, 2011

Top results

In animal inflammation models, GB‑115 showed anti-inflammatory effects. (Bulletin of experimental biology and medicine, 2011)
In mice with experimental autoimmune encephalomyelitis, GB‑115 promoted recovery of thymus weight. (Bulletin of experimental biology and medicine, 2011)
In animal tests, GB‑115 reduced the inflammatory reaction to concanavalin A. (Eksperimental'naia i klinicheskaia farmakologiia, 2010)

Pain

9 results · 9 animal

In mice, GB‑115 increased morphine-induced pain relief in the hot-plate test. Bulletin of experimental biology and medicine, 2007

Top results

In mice, GB‑115 increased morphine-induced pain relief in the hot-plate test. (Bulletin of experimental biology and medicine, 2007)
In mice, oral GB‑115 reduced abdominal contractions caused by acetic acid. (Bulletin of experimental biology and medicine, 2012)
In mice, GB‑115 increased hot plate response time independently of naloxone. (Eksperimental'naia i klinicheskaia farmakologiia, 2007)

All 4 studies in people

In people

In patients with anxiety, adverse event frequency did not differ significantly between Ranquilon and Afobazol.

2026Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova200 people

In people

In patients with generalized anxiety disorder, the abstract described GB‑115 as safe and well tolerated.

2019Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova31 people

In people

In patients with generalized anxiety disorder, none had stimulation-related side effects during GB‑115 treatment.

2022European psychiatry25 people

In people

In patients with generalized anxiety disorder, reaction time decreased versus background during GB‑115 treatment.

2022European psychiatry25 people

All 21 GB-115 studies by area Open the Scientific page

Key GB-115 studies

Studies in people come first, then studies in animals and in the lab.

People
[Comparative study of the efficacy and safety of Ranquilon and Afobazol in the treatment of patients with anxiety associated with neurasthenia and adjustment disorders. (Results of an open, randomized, multicenter, phase IV clinical study)]
Karavayeva et al. 2026 · Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova · 200 people · cited by 0
11 results
People
[Results of a clinical study of a new anxiolytic, a blocker of central cholecystokinin receptors]
Neznamov et al. 2019 · Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova · 31 people · cited by 1
7 results
People
Clinical effects of central antagonist of cholecystokinin-1 receptors GB-115 in patients with Generalized Anxiety Disorder
Dorofeeva et al. 2022 · European psychiatry : the journal of the Association of European Psychiatrists · 25 people · cited by 0
3 results
People
Impact of central antagonist of cholecystokinin-1 receptors GB-115 on cognitive functions in patients with Generalized Anxiety Disorder
Dorofeeva et al. 2022 · European psychiatry : the journal of the Association of European Psychiatrists · 25 people · cited by 0
3 results
Animals
Influence of Retrodipeptide Analogue of Cholecystokinin Tetrapeptide (GB-115) and Phenazepam on the Behavior of Rhesus Monkeys under Isolation Conditions
Panchenko et al. 2025 · Doklady. Biochemistry and biophysics · 4 subjects · cited by 0
2 results

All 21 GB-115 studies

GB-115 clinical trials

ClinicalTrials.gov lists 2 trials of GB-115. 1 is active or planned, and 0 have posted results. PepBank does not show trial results.

Solid bars are dates that happened. Hatched bars are planned dates. Data from ClinicalTrials.gov.

Efficacy and Safety of Ranquilon in Patients With Anxiety Disorders Due to Neurasthenia and Adjustment Disorders

Phase 4recruiting250 planned

A Study of the Efficacy and Safety of Ranquilon Tablets in Patients With Anxiety in Neurasthenia and Adjustment Disorders

Phase 3completed220 people

Status and safety

Is GB-115 approved?

FDA

United States

Status unknown

Status unknown.

EMA

European Union

Status unknown

Status unknown.

WADA

Sport

Not recorded

Status unknown.

Yes. Approved in Russia only. Status unknown.

Laws and labels change, so check the regulator for the current status.

GB-115 side effects and safety

PepBank has 26 safety results from studies of GB-115. 14 of them come from studies in people.

Safety results from studies (26)

In patients with anxiety, adverse event frequency did not differ significantly between Ranquilon and Afobazol. (Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova, 2026)
In patients with generalized anxiety disorder, GB‑115 did not induce initial overactivation. (Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova, 2019)
In patients with generalized anxiety disorder, none had stimulation-related side effects during GB‑115 treatment. (European psychiatry, 2022)
In patients with anxiety, both Ranquilon and Afobazol groups reported only mild adverse events. (Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova, 2026)
In patients with anxiety, neither Ranquilon nor Afobazol groups reported serious adverse events. (Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova, 2026)
In patients with anxiety, neither Ranquilon nor Afobazol groups reported severe adverse events. (Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova, 2026)
In patients with anxiety, neither Ranquilon nor Afobazol groups reported fatal adverse events. (Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova, 2026)
In patients with anxiety, adverse events caused no treatment discontinuations in either Ranquilon or Afobazol groups. (Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova, 2026)
In patients with anxiety, neither Ranquilon nor Afobazol treatment showed clinically significant vital sign abnormalities. (Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova, 2026)
In patients with anxiety, neither Ranquilon nor Afobazol treatment showed clinically significant laboratory abnormalities. (Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova, 2026)
In patients with anxiety, neither Ranquilon nor Afobazol treatment showed clinically significant ECG abnormalities. (Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova, 2026)
In patients with generalized anxiety disorder, the abstract described GB‑115 as safe and well tolerated. (Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova, 2019)
In patients with generalized anxiety disorder, GB‑115 did not induce initial anxiety. (Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova, 2019)
In patients with generalized anxiety disorder, GB‑115 did not induce sleep disturbances. (Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova, 2019)
In rats, GB‑115 withdrawal did not increase anxiety. (Vestnik Rossiiskoi akademii meditsinskikh nauk, 2011)
In mice, no animals died after an acute oral GB‑115 dose of 6000 mg/kg. (Eksperimental'naia i klinicheskaia farmakologiia, 2010)
In rats, GB‑115 withdrawal did not produce aggression. (Vestnik Rossiiskoi akademii meditsinskikh nauk, 2011)
In rats, GB‑115 withdrawal did not produce convulsive manifestations. (Vestnik Rossiiskoi akademii meditsinskikh nauk, 2011)
In rats, no animals died after an acute oral GB‑115 dose of 3500 mg/kg. (Eksperimental'naia i klinicheskaia farmakologiia, 2010)
In rabbits and rats, oral GB‑115 for 6 months caused no irreversible pathological changes in the organs and systems studied. (Eksperimental'naia i klinicheskaia farmakologiia, 2010)
In animal safety tests, GB‑115 did not affect reproductive function. (Eksperimental'naia i klinicheskaia farmakologiia, 2010)
In animal safety tests, GB‑115 did not affect offspring development before birth. (Eksperimental'naia i klinicheskaia farmakologiia, 2010)
In animal safety tests, GB‑115 did not affect offspring development after birth. (Eksperimental'naia i klinicheskaia farmakologiia, 2010)
In preclinical safety tests, GB‑115 showed no allergenic activity. (Eksperimental'naia i klinicheskaia farmakologiia, 2010)

See every safety result on the Scientific page

Doses studied (27 shown)

The doses that these studies used. They are not recommendations.

Dose as reported	Class	Species	Route	Duration	Design	Source
6 mg/day	Human	human	oral	28 days	Randomized trial in people · n = 200	Karavayeva 2026
6 mg per day	Human	human	oral	21 days	Trial in people without random groups · n = 31	Neznamov 2019
6 mg daily	Human	human	Not reported	21 days	Trial in people without random groups · n = 25	Dorofeeva 2022
6 mg/d	Human	human	Not reported	Not reported	Trial in people without random groups · n = 25	Dorofeeva 2022
0.001 g	Animal	Macaca mulatta	oral	Not reported	Study in live animals · n = 4	Panchenko 2025
0.002 g	Animal	Macaca mulatta	oral	Not reported	Study in live animals · n = 4	Panchenko 2025
0.05-0.2 mg/kg	Animal	rat	oral and intraperitoneal	Not reported	Study in live animals	Gudasheva 2007
0.006-0.100 mg/kg	Animal	mouse	Not reported	Not reported	Study in live animals	Kolik 2003
0.025 and 0.05 mg/kg	Animal	rat	Not reported	Not reported	Study in live animals	Kolik 2003
0.1-0.5 mg/kg	Animal	mouse	oral	Not reported	Study in live animals	Kolik 2013
0.1 and 5.0 mg/kg	Animal	mouse	oral	Not reported	Study in live animals	Kolik 2013
0.5-0.7 mg/kg	Animal	rat	oral	Not reported	Study in live animals	Kolik 2013
0.1 mg/kg	Animal	mouse	oral	Not reported	Study in live animals	Kolik 2013
0.1-20 mg/kg	Animal	mouse	peroral	Not reported	Study in live animals	Kolik 2012
0.1, 1, and 10 mg/kg	Animal	Not reported	intraperitoneal	Not reported	Study in live animals	Shipaeva 2011
1 mg/kg	Animal	mouse	intraperitoneal	Not reported	Study in live animals	Shipaeva 2011
0.1-10 mg/kg	Animal	mouse	Not reported	Not reported	Study in live animals	Shipaeva 2008
4 mg/kg	Animal	mouse	intraperitoneal	Not reported	Study in live animals	Kolik 2007
0.025 and 4 mg/kg	Animal	rat	intraperitoneal	Not reported	Study in live animals	Kolik 2007
0.025 mg/kg	Animal	rat	intraperitoneal	14 days	Study in live animals	Kolik 2016
0.3 mg/kg	Animal	rat	oral	Not reported	Study in live animals	Kolik 2015
0.1 mg/kg daily	Animal	rat	intraperitoneal	30 days	Study in live animals	Kolik 2011
0.1 and 0.5 mg/kg	Animal	rat	intraperitoneal	Not reported	Study in live animals	Kolik 2011
6000 mg/kg	Animal	mouse	oral	Not reported	Study in live animals	Sorokina 2010
3500 mg/kg	Animal	rat	oral	Not reported	Study in live animals	Sorokina 2010
0.1 and 10 mg/kg	Animal	rabbit and rat	oral	6 months	Study in live animals	Sorokina 2010
10 mg/kg	Animal	Not reported	Not reported	Not reported	Study in live animals	Sorokina 2010

From the community

How people use it

What people report online. It comes from forums and guides, not from studies.

Community-reported. Not tested in trials.

The Russian Ranquilon label describes oral use in adults aged 18 years or older. This label regimen does not establish community practice.

Reported routines and cautions

What people use it for

Anxiety in neurasthenia and adjustment disorders in adults aged 18 years or olderS2

Reported regimens

Regimens that community sources report for GB-115. Community-reported, not tested in trials.
Context	Route	Amount	How often	How long	Agreement	Sources
Anxiety in neurasthenia and adjustment disorders in adults aged 18 years or olderOfficial label dosing of an approved product	oralDuring or after a meal	2 mg per dose	Three times daily	28 days	The manufacturer leaflet and HTML mirror agree on the regimen and adult indication. The mirror carries pharmacy purchase links. These label versions do not establish community practice.	S2

Community sources

S2Ranquilon Russian patient leaflet mirrormedi.rucarries seller links, not linked

plus 1 seller page (not linked)

Gaps

Separate community practice remains unestablished. The HTML-only quote script cannot verify the manufacturer PDF. All retained quotes come from the HTML mirror. The versions differ in excipients, packaging and listed manufacturer. Their revision relationship remains unresolved.

Questions and more

Ask a question about GB-115

The answer links to every study it uses.

What does the evidence say about GB-115?Is GB-115 tested in people?Compare with Delta sleep-inducing peptide (DSIP)Compare with Cerebrolysin

Sources

Database: PepBank data for GB-115 (data version 308560)
Regulator: FDA status record
Regulator: WADA status record
Trial registry: ClinicalTrials.gov
Community: community sources (forums and guides), as summarized in the PepBank community file

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

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GB-115

GB-115 at a glance