Selank side effects and risks

Reported side effects

• Unpleasant taste: Russian instructions describe taste when nasal solution reaches the throat; no rate given., mild (source)
• Allergic reaction: Possible with intolerance; no frequency estimate in Russian instructions., serious (source)
• Longer sleep: 13% Selank versus 93% phenazepam on day 14 in a 60 person open trial., mild (source)
• Memory problems: 10% Selank versus 83% phenazepam on day 14 in the same trial., moderate (source)
• Concentration problems: 7% Selank versus 97% phenazepam on day 14., moderate (source)
• Weakness or fatigue: 3% Selank versus 77% phenazepam on day 14., mild (source)
• Nasal dryness: 7% Selank versus 0% phenazepam on day 21, one week after treatment stopped., mild (source)

Stop and get help if

• Trouble breathing, face or throat swelling, or collapse: Stop exposure and get emergency care now.
• Sudden weakness, facial droop, speech trouble or sudden vision loss: Call emergency services immediately; do not delay stroke care for a peptide.

Who should avoid it

• pregnant: Russian instructions contraindicate pregnancy; controlled pregnancy safety studies are absent.
• breastfeeding: Russian instructions contraindicate breastfeeding; infant exposure and safety are unknown.
• tryingToConceive: Precaution: reproductive safety and a preconception washout interval are not established.
• under18: Russian pediatric use does not establish safety of online preparations.
• other: Avoid after allergy to the peptide or formulation, including its preservatives.
• testedAthlete: 2026 status is unresolved for the exact substance and formulation; obtain an anti-doping ruling.
• kidneyDisease: No reliable dose-adjustment studies for kidney impairment were located.
• liverDisease: No reliable dose-adjustment studies for liver impairment were located.
• psychiatricCondition: Review symptoms and psychiatric medicines; the available trials do not cover every diagnosis or combination.
• other: Blocked or irritated nasal passages can make delivery unreliable; review persistent nose symptoms.
• autoimmuneDisease: Immune-marker changes were reported; effects in autoimmune disease are unstudied. This is a precaution.
• immunosuppressed: Immune effects and interactions with immune-suppressing care are unknown. This is a precaution.
• seizureDisorder: Safety in seizure disorders is not established; review neurological history and medicines.

Interactions

• Benzodiazepines and other sedating substances: A small phenazepam study does not establish safety with other sedatives. Sedation still occurred with the combination.
• Antidepressants and antipsychotics: One small escitalopram study and laboratory data do not establish safety across these drugs.
• Semax and modified nootropic peptides: The combination is reported online; the brain-imaging study tested separate drug groups.

Product quality risks

• Seized powders were identified as Semax and Selank by mass spectrometry; that study did not establish sterility or a market-wide contamination rate.
• FDA flags immune reactions from aggregation and peptide-related impurities. A nasal route does not remove quality risks.
• Unregulated preparations can contain the wrong amount, microbes or bacterial toxins. No representative assay survey of these two products was found.