Selank and Afobazole are two Russian preparations developed to reduce anxiety and improve stress resistance. Although both have anxiolytic effects without causing significant drowsiness, they differ in structure, method of administration, mechanism of action, and the speed at which effects occur.
What are Selank and Afobazole?
Selank is a synthetic heptapeptide composed of seven amino acids. It was designed as an analog of the natural peptide tuftsin, which is involved in communication between the immune and nervous systems. Selank is administered nasally, and studies suggest it can reach the central nervous system very quickly. It was developed in Russia and Ukraine in the 1990s and is approved there for the treatment of anxiety disorders and stress-related conditions.
Afobazole (fabomotizole) is a synthetic chemical compound available in tablet form. It was also developed in Russia in the late 1990s. It primarily works by activating sigma-1 receptors, which are involved in regulating the cellular response to stress. Like Selank, it was designed not to cause significant sedation.
How Do They Get Into the Body?
| Feature | Selank | Afobazole |
|---|---|---|
| Method of administration | Nasal spray - a few doses in each nostril | Tablet taken orally, usually 3 times a day |
| How quickly does it reach the brain | Very quickly – through the nasal cavity directly to the brain, bypassing the digestive process | It is absorbed through the gastrointestinal tract; maximum blood concentration is reached after approximately 1 hour. |
| How long does it last? | The main peptide breaks down in about 2 minutes, but active fragments can last for 3-4 hours. | The main compound is eliminated relatively quickly (about 50 minutes), while its metabolite remains active for up to 6 hours |
| How is it removed from the body | Broken down into harmless protein fragments and excreted by the kidneys within 24 hours | Approximately 85% is excreted by the kidneys, and 15% by the gastrointestinal tract; it is completely eliminated within one day |
| How many substances become biologically available | High bioavailability in the brain due to intranasal administration and bypassing hepatic metabolism | Approximately 43–55% of the administered dose enters the bloodstream after passing through the liver |
How do they reduce anxiety?
Both preparations reduce anxiety symptoms without acting like typical sedatives or sleeping pills. Neither is designed to induce drowsiness.
| Feature | Selank | Afobazole |
|---|---|---|
| Main anxiolytic effect | It supports the action of GABA—the primary inhibitory neurotransmitter—without excessively suppressing brain activity | It activates sigma-1 receptors, which help cells cope with stress signals; it also affects melatonin receptors |
| Impact on brain health | Increases BDNF and NGF levels, supporting communication between neurons, memory, and concentration | It may increase BDNF by activating sigma-1 receptors, thereby supporting nerve cell regeneration |
| Effect on mood | It gently affects serotonin and dopamine pathways, producing a mild mood-enhancing effect | The benefits primarily concern stress and anxiety regulation, not direct mood improvement. |
| Effects on the immune system | It exhibits immunomodulatory properties and may help regulate inflammatory processes | The anti-inflammatory effect seems significantly weaker |
| Risks of Sedation | No significant drowsiness was observed | No significant drowsiness was observed |
| Risk of addiction | No evidence of tolerance, dependence, or withdrawal symptoms | In studies lasting up to 12 weeks, no cases of dependence or withdrawal symptoms were reported |
How Effective Are They?
| Feature | Selank | Afobazole |
|---|---|---|
| Start of operation | Fast – the first effects may appear within 20–60 minutes | Gradual – the full anti-anxiety effect usually develops after 2–4 weeks of regular use |
| Typical dosage used in studies | 400–600 micrograms intranasally, 1–3 times a day | 10 mg three times a day (for a total of 30 mg per day) |
| Main Areas of Research | Generalized anxiety, short-term stress, stress-related memory and concentration problems | Generalized anxiety, adjustment disorders, and nicotine withdrawal support |
| Clinical trials | About 15 clinical trials in Russia and Ukraine; results superior to placebo and comparable to older anti-anxiety medications | More than 20 clinical trials in Russia, some involving up to 500 patients; benefits over placebo were demonstrated |
| Effects on Memory and Concentration | Well-documented benefits for working memory, attention, and | Cognitive benefits appear to be secondary and not the primary goal of the research. |
| Adverse events | Mild and rare: slight nasal irritation, temporary fatigue, occasional headache | Mild and rare: nausea, mild stomach discomfort, and occasional allergic reactions |
| Interactions with other substances | No significant interactions with liver enzymes are known. | Metabolized by the enzyme CYP3A4, so it may interact with certain medications |
| Biggest limitation | Most research has been conducted exclusively in Russia and Ukraine; limited long-term data | Similar geographical limitations and lack of large clinical trials in the USA, UK, and EU |
How do they work for anxiety?
Both preparations reduce anxiety symptoms, but they utilize different biological mechanisms.
Selank
Research shows that Selank:
- modulates GABAergic signaling,
- affects neurotrophic factors, such as BDNF and NGF,
- may interact with serotonergic and dopaminergic systems,
- It exhibits neuroregulatory and immunomodulatory properties.
Afobazole
Research suggests that Afobazole:
- activates sigma-1 receptors,
- supports cell adaptation to stress,
- may affect melatonin receptors,
- focuses primarily on regulating chronic stress and anxiety.
Neither of the preparations was designed as a classic sedative, and both seem to be characterized by a low risk of sedation and addiction.
Which works faster?
One of the biggest differences between these substances is the time it takes for the effects to appear.
Selank it is primarily studied in the context of faster reduction of tension and stress, and support for cognitive functions.
Afobazole usually requires regular use for several weeks and is more often discussed in the context of chronic, persistent anxiety.
Impact on Cognitive Functions
Research on Selank indicates potential benefits regarding:
- working memory,
- concentration,
- stress resistance,
- Cognitive functions under psychological stress.
Afobazole may also exhibit some cognitive benefits, but these are not its primary area of research.
Security Profile
Available studies suggest that both preparations are generally well tolerated.
Selank
- sporadic nasal irritation,
- occasional headache,
- fleeting fatigue.
Afobazole:
- mild stomach upset,
- nausea,
- rare allergic reactions.
Published studies have not found a significant risk of addiction or withdrawal symptoms for any of these preparations.
Disclaimer
The content is for educational and informational purposes only and should not be interpreted as medical advice, diagnosis, or therapeutic recommendation. Selank and Afobazole have not been approved by the U.S. Food and Drug Administration (FDA) or the European Medicines Agency (EMA) for the treatment of anxiety disorders or other conditions. Most available data comes from studies conducted in Russia and Eastern Europe. Additional, well-designed clinical trials are needed to better determine their efficacy, safety, and long-term effects.