Three peptides cover the cognitive-focus space in this catalogue: Semax for focus and output, Selank for anxiety smoothing, and Dihexa for plasticity / synaptogenesis. The first two have a real Russian clinical history at modest doses; Dihexa is biologically interesting and structurally riskier than the rest of this catalogue.
The audience this site is written for already knows the standard nootropic stack (caffeine + L-theanine + sleep + exercise). The peptides below are the marginal lever for users who’ve done that groundwork. None of them rescue a structurally sleep-deprived, caffeine-dysregulated baseline.
The shortlist by goal
Semax - focus / output anchor
- What it is. A 7-amino-acid synthetic ACTH(4-7) analogue developed in the 1980s by the Russian Academy of Medical Sciences. Originally indicated for stroke recovery and cognitive impairment; widely used in Russian neurology.
- Mechanism. Acute BDNF and NGF upregulation; cholinergic and dopaminergic modulation; neuroprotective effects in ischemia models.
- Evidence framing. Tier: Clinical for the Russian neurology indications (stroke, ischemia, mild cognitive impairment), but Western replication is sparse and the original literature is not widely indexed in Western databases. Tier: Limited data for healthy-adult nootropic use specifically.
- Protocol. Intranasal 0.1% solution, 200–600 mcg (1–3 sprays per nostril) in the morning. Onset 10–20 minutes. Effects last 12–24 hours. The 1.0% solution is the high-dose stroke formulation - not the standard nootropic dose.
- Storage matters. Liquid Semax degrades quickly at room temperature. Refrigeration is required between uses.
Selank - calm focus, anxiolysis
- What it is. A 7-amino-acid analogue of tuftsin, developed in parallel with Semax by the same research line. Russian indications include generalised anxiety disorder.
- Mechanism. Modulation of the GABA / serotonin / dopamine balance - produces anxiolysis without the sedation profile of benzodiazepines or the dependence risk. Some BDNF effects similar to Semax.
- Evidence framing. Tier: Clinical for generalised anxiety in the Russian literature; tier: Limited data for cognitive-performance use specifically. Real anxiolytic effect for many users; placebo-driven for some.
- Protocol. Intranasal 0.15% solution, 200–300 mcg (1–2 sprays per nostril) as needed for situational anxiety, or daily morning for a smoother baseline. Onset 5–15 minutes.
- N-Acetyl variant. Some users prefer N-Acetyl Selank for proposed better BBB penetration. Clinical data is on standard Selank; the modification is theoretical.
Dihexa - speculative plasticity wing
- What it is. Angiotensin IV analogue developed by Joe Harding’s lab at Washington State. Hepatocyte growth factor (HGF) potentiator; in animal models induces synaptogenesis several orders of magnitude stronger than BDNF.
- Evidence framing. Tier: Preclinical. Animal-model data is genuinely impressive (Alzheimer’s rat models, dementia recovery signals). Human data: zero published trials. Community use is real but evidence is community-log quality.
- Why this matters. The mechanism is growth-factor potentiation. The same property that makes it interesting for cognitive recovery makes the long-term safety profile harder to characterise - cancer risk, off-target growth signalling, anywhere HGF acts (which is almost everywhere). The animal data is on short-duration use; human chronic use is the open question.
- Protocol. 5–20 mg orally weekly, or 5 mg daily. Transdermal in DMSO carrier as an alternative to avoid first-pass metabolism. 4 weeks on / 4 weeks off cycling is the standard community discipline.
- Where it doesn’t fit. Anyone with a cancer history, family history of cancer in first-degree relatives, or hesitation about uncharacterised long-term growth-factor exposure. See Cancer Risk and Growth Factors for the per-mechanism risk frame.
Decision guide
- Have you actually fixed sleep, exercise, and caffeine
discipline?
→ If not, fix that first. None of the compounds below rescues a broken baseline. - What’s the limiter - output, anxiety,
or both?
→ Output / focus → Semax morning.
→ Anxiety / jitter → Selank as needed or morning.
→ Both / "calm focus" → Semax + Selank stacked. - Is plasticity / structural recovery the goal (post-
concussion, post-stress, age-related decline)?
→ Dihexa enters the conversation, with the cycling and cancer-screen caveats. Not for routine focus enhancement. - Cancer history or first-degree-relative early-onset
cancer?
→ Skip Dihexa. Semax and Selank remain reasonable options. - Tested athlete?
→ Semax and Selank are non-approved Russian compounds, fall under WADA S0 catch-all. Dihexa is also S0 / S2 mimetic. None of these is compatible with tested competition without TUE pathway.
Representative stacks
Stack 1 - Focus output (default)
- Semax 0.1% intranasal, 200–600 mcg morning
- Optional: re-dose midday if the 12-hour window doesn’t span the workday
- Refrigerate between uses
Stack 2 - Calm focus / "Zen"
- Stack 1 base (Semax morning)
- Selank 0.15% intranasal, 200–300 mcg with the Semax dose, or as needed mid-day for anxiety spikes
- Skip if jitter resolves - Selank works well as a tool, less well as a continuous baseline
Stack 3 - Speculative plasticity (advanced operators only)
- Dihexa 5 mg daily oral (or 10–20 mg weekly), 4 weeks on / 4 weeks off
- Stack 1 base for the BDNF amplification
- Cancer-history screen before starting (see Cancer Risk and Growth Factors)
- Pre/post bloodwork: CBC, CMP, fasting glucose, plus baseline cognitive testing if measuring effect rigorously
What stops people
- Expecting a stimulant. Semax isn’t caffeine. The effect is more "smoothed cognition" than "wired." Users expecting a kick set themselves up for "I don’t feel anything" reports.
- Storing Semax at room temperature. The refrigeration requirement is real. Two weeks of room-temp Semax is half-degraded at best, useless at worst.
- Running Selank continuously when it’s a tool. Continuous use blunts the situational benefit. Use it as needed if anxiety is situational; if anxiety is structural, Selank isn’t the right framing - clinical evaluation is.
- Treating Dihexa as a routine nootropic. The growth-factor mechanism is real. The cycling discipline isn’t optional. Operators who run Dihexa continuously have the worst long-tail signal in this stack.
- Sourcing problems. Both Semax and Selank are legitimate prescription products in Russia and counterfeited everywhere else. The Russian originals (Innopharm) are the reference. See Sourcing and Verification.
Monitoring
- Subjective output journal. Daily 1–10 rating of focus, mood, output. The cleanest signal for these compounds is what users actually report; the labs don’t move much.
- Anxiety scale (e.g. GAD-7) for Selank protocols. Quick and free; 4-week intervals.
- Cognitive testing if running Dihexa. Cambridge Brain Sciences or similar baseline + post-cycle. The signal is subtle; objective measurement is worth the effort.
- Bloodwork if running Dihexa. CBC, CMP, fasting glucose at baseline and post-cycle. Standard for any growth- factor-active compound.
Cross-references
- Cancer Risk and Growth Factors - the per-mechanism risk frame for Dihexa specifically.
- Sourcing and Verification - counterfeit risk for the Russian compounds.
- Sleep and Recovery application - for users where focus problems are downstream of sleep problems (most users).
- Cycling Strategies - the on/off rationale for Dihexa.