GB-115

GB-115 is a synthetic dipeptide anxiolytic developed at the Zakusov Research Institute of Pharmacology in Moscow. Structurally it is a retro-analogue of the C-terminal tetrapeptide of cholecystokinin (CCK-4), built around an L-tryptophan-containing dipeptide scaffold, and it was designed to act as a low-affinity blocker of central cholecystokinin receptors ^[1][2].

The cholecystokinin system is a well-studied modulator of anxiety and panic, which is the rationale behind GB-115; by dampening central CCK signaling it aims to relieve anxiety without the sedation, muscle relaxation, or dependence associated with benzodiazepines ^[5][6]. Its research profile is notable for a phenotype-specific pattern, in which its effects depend on the animal's characteristic stress-response style ^[2].

Its research applications include a substantial preclinical program and early clinical evaluation. Animal studies established anxiolytic activity through the cholecystokinin system ^[2], confirmed that the effect persists after oral administration ^[3], demonstrated antidepressant-like activity independent of stress-response phenotype ^[4], and characterized an antinociceptive action involving interactions between the cholecystokinin and opioid systems ^[5]. A separate line of work showed that, unlike diazepam, chronic GB-115 produced neither tolerance nor a withdrawal syndrome on discontinuation ^[6]. In a clinical study of patients with generalized anxiety disorder, GB-115 in tablet form produced a fast-onset anxiolytic effect with favorable changes in attention, reaction time, and overall performance, and good tolerability ^[1].

GB-115 is not an approved medicine in the United States or Europe and remains investigational outside its country of origin; it is encountered as a research compound. Its evidence base is concentrated in the laboratories that developed it, and independent replication is limited.

Across Phase 1, 2, and 3 trials the side effect profile was near-placebo. In Phase 3, 25.5 percent of the GB-115 group reported adverse events versus 14.6 percent on placebo, a difference the authors judged non-significant; every event was mild and no one dropped out. Unlike benzodiazepines, GB-115 does not relax muscles, and it lacks the abuse potential, toxicity, and dangerous withdrawal that define that class. Most data still come from Russian labs, so independent replication is the main open question. Not medical advice.

GB-115 is a synthetic dipeptide anxiolytic developed in Russia at the V. V. Zakusov Research Institute of Pharmacology, an institution known for its rational, structure-based approach to designing small peptide neuroactive molecules. It emerged from the research program of Tatiana Gudasheva and Sergei Seredenin, who pioneered the strategy of building short dipeptide mimetics that reproduce the active fragments of larger signaling peptides.

In the case of GB-115, the design target was the cholecystokinin system, and the molecule was conceived as a retro-analogue related to the cholecystokinin-4 fragment, intended to act on central cholecystokinin receptors that help set the brain's anxiety and panic tone.

Reported preclinical and early clinical work describes it as an anxiolytic that, unlike benzodiazepines, avoids sedation, muscle weakness, and dependence, and that in a small study of generalized anxiety disorder patients actually improved attention and reaction speed.

Because its development and much of its literature originate in the Russian pharmacological tradition, GB-115 is not indexed in mainstream English-language databases such as PubMed, and its documentation remains comparatively limited outside that body of work. It is best understood as a promising investigational research compound rather than an established medicine.

GB-115 has an intriguing reputation as a rare example of an anxiolytic that appears to calm anxiety while keeping the mind clear, a combination that almost nothing in the classic sedative category manages. Rather than dulling the user, it targets the cholecystokinin CCK-1 receptor, a pathway tied specifically to chronic anxiety and panic, and in an early clinical study of generalized anxiety disorder it was reported to sharpen attention and reaction time even as it eased symptoms.

Animal work is encouraging in its texture, describing a fast onset, no development of tolerance across chronic dosing, and none of the rebound anxiety seen after benzodiazepine withdrawal. It also carried antidepressant-like activity in some models, hinting at combined mood and anxiety applications.

The honest limitation is that the human evidence is early and small, and the literature is concentrated in Russian-language sources that are not widely indexed internationally. For those seeking calm without fog, weakness, or dependence, it is a genuinely fascinating research anxiolytic.