Neurotrophic / nootropic

Cognitive & nootropic peptides

The cognitive peptide class spans three mechanistically distinct families: ACTH-derived fragments (Semax) that induce BDNF and NGF in limbic and cortical regions; tuftsin analogs (Selank) that modulate GABAergic and serotonergic tone with anxiolytic profiles; and angiotensin-IV-derived analogs (Dihexa) that act as hepatocyte-growth-factor (HGF) mimetics with synaptogenic activity. Most are delivered intranasally because the nasal mucosa provides direct olfactory and trigeminal pathways to the CNS that bypass first-pass metabolism.

Semax — ACTH(4-7)Pro-Gly-Pro

Sequence: MEHFPGP — first four residues are ACTH(4-7) with a stabilizing Pro-Gly-Pro C-terminal extension.
Molecular weight: ~813 Da.
Proposed mechanism: rapid, robust upregulation of BDNF and NGF mRNA and protein in hippocampus and cortex; modulation of monoaminergic tone; neuroprotective effects in ischemia research models.
Variants: N-Acetyl-Semax and N-Acetyl-Semax amidate add an acetyl group to the N-terminus (and an amide cap on the C-terminus in the amidate version) for protease resistance and longer duration of action in research models.
Delivery: intranasal — typical research preparations are 1 mg/mL solutions in saline, delivered as drops or metered spray.
Status: registered nootropic in Russia (originally developed at the Institute of Molecular Genetics); not approved in the US, EU, or UK.

Selank — tuftsin analog

Sequence: TKPRPGP — based on the immunomodulatory peptide tuftsin (TKPR) with a Pro-Gly-Pro stabilizing extension.
Molecular weight: ~751 Da.
Proposed mechanism: anxiolytic activity via GABAergic and serotonergic modulation, increased expression of BDNF and the enkephalin-degrading enzyme, immunomodulatory effects via tuftsin-receptor activity on macrophages.
Variants: N-Acetyl-Selank amidate is the protease-resistant form used in most contemporary research.
Delivery: intranasal, same format as Semax.
Distinguishing feature: in research models, anxiolytic effects without sedation, dependence liability, or withdrawal — distinct from benzodiazepine-class anxiolytics.

Dihexa — HGF mimetic

Sequence: N-hexanoic-Tyr-Ile-(6)-aminohexanoic-amide — a hexapeptide-derived small molecule from the angiotensin IV family.
Molecular weight: ~519 Da.
Proposed mechanism: potentiates hepatocyte growth factor (HGF) binding at its c-Met receptor in the CNS, driving synaptogenesis and spinogenesis in hippocampal research models. Reported in research as orders of magnitude more potent than BDNF on a molar basis at promoting dendritic spine formation.
Delivery: orally bioavailable (the hexanoic and aminohexanoic groups provide membrane permeability); also delivered intranasally in some research preparations.
Status: early-stage research compound; no clinical approvals.

Cerebrolysin — porcine neuropeptide complex

What it is: a hydrolysate of porcine brain protein — a mixture of low-molecular-weight peptides (≤10 kDa) and free amino acids, standardized for neurotrophic activity. Not a single defined molecule.
Proposed mechanism: mimics the actions of endogenous neurotrophic factors (BDNF, NGF, GDNF, CNTF) via signaling-cascade fragments rather than receptor binding; modulates APP processing in research models of Alzheimer's pathology.
Delivery: intramuscular or intravenous infusion in research and clinical contexts.
Status: approved for clinical use in some jurisdictions (parts of Europe, Asia, Russia, Latin America) for stroke and dementia indications; not FDA-approved in the US.

Emerging neurogenic peptides

P21

A four-amino-acid peptidergic compound derived from the active region of the ciliary neurotrophic factor (CNTF) family, designed to be brain-penetrant. Research focus: adult hippocampal neurogenesis and amyloid-related cognitive models.

FGL (FG-loop peptide)

Derived from the second fibronectin-type-III module of the neural cell adhesion molecule (NCAM). Acts as an FGFR agonist in research models, with reported effects on long-term potentiation, learning, and neuronal survival.

Intranasal delivery — why it dominates this class

The intranasal route is favored across the cognitive peptide class for three reasons:

CNS access: the olfactory and trigeminal nerve pathways bypass the blood–brain barrier and deliver a fraction of the dose directly to perivascular CSF — particularly relevant for peptides that would not otherwise cross BBB at meaningful concentrations.
First-pass avoidance: peptides delivered intranasally avoid hepatic first-pass degradation that destroys orally administered peptides.
Local enzymatic environment: the nasal mucosa is far less protease-rich than the GI tract, so unstabilized peptides survive long enough to be absorbed.

Research preparations are typically 1 mg/mL in saline or BAC water, delivered with a calibrated metered-dose nasal spray or a graduated dropper.

Reconstitution and storage

Standard cold-chain peptides — reconstitute with BAC water (or sterile saline for intranasal use), store at 2–8 °C, use within 30 days. The Pro-Gly-Pro stabilized variants (Semax, Selank, and their N-acetyl forms) are notably more stable than the parent fragments. Full per-vial math is in the dosage protocols guide; cold-chain rules in the storage & handling guide.

Safety, risks & legal notice

Read before ordering or conducting any research

For laboratory research only

Every compound described on this page is sold and provided strictly as a research-grade reagent for in-vitro and animal-model studies. These products are not intended for human consumption, cosmetic use, dietary supplementation, or any clinical or therapeutic application. By purchasing, you represent that you are a qualified researcher, laboratory, or educational institution with appropriate facilities and oversight.

Not FDA-approved or evaluated

None of the compounds on this page have been approved by the U.S. Food and Drug Administration (FDA), the European Medicines Agency (EMA), or equivalent bodies for the indications discussed in research contexts. Safety and efficacy profiles in humans are unknown, incompletely characterized, or based solely on pre-clinical and investigator-initiated studies.

No medical, clinical, or dosing advice

Dr Jays Peptides does not employ physicians, pharmacists, or clinical researchers. Nothing on this page — including dosage figures, reconstitution math, or mechanism descriptions — constitutes medical advice, a prescribing recommendation, or instructions for self-administration. If you are considering any peptide for personal use, consult a licensed healthcare provider who can evaluate your individual risk factors, medication interactions, and monitoring needs.

Class-specific risk signals

Limited human safety data: Semax and Selank have post-marketing pharmacovigilance data only from Russia and a few other jurisdictions with different regulatory standards. Dihexa, P21, and FGL have essentially no human safety data.
Intranasal delivery risks: chronic intranasal administration can cause mucosal irritation, epistaxis, and potentially alter olfactory epithelium integrity. The actual CNS bioavailability of intranasal peptides remains debated and compound-dependent.
BDNF/NGF overstimulation: excessive neurotrophic factor signaling may theoretically promote excitotoxicity, epileptiform activity, or aberrant synaptic pruning in susceptible individuals. No clinical seizure signal has been reported, but the theoretical risk exists.
Immunogenicity (Cerebrolysin): as a porcine-derived hydrolysate, Cerebrolysin carries a non-zero risk of allergic reaction or sensitization, including rare anaphylaxis reports in clinical use.
Porcine tissue concerns: Cerebrolysin is derived from porcine brain tissue. While manufacturing removes infectious agents, prion-disease theoretical risk (however remote) is a consideration in some research ethics reviews.
Cerebrolysin route of administration: IV/IM administration requires sterile technique and monitoring for acute reactions during infusion — not appropriate for unsupervised settings.

General risk factors

Purity and contamination: Research peptides are not manufactured to pharmaceutical-grade GMP standards. Even high-purity lots may contain trace endotoxins, residual solvents, or unrelated peptide sequences.
Stability and degradation: Improper storage, repeated freeze–thaw cycles, or use beyond recommended reconstitution windows can produce degraded products with unknown toxicology.
Immunogenicity: Foreign peptides can elicit antibody responses; repeated administration may cause allergic reactions or neutralizing antibodies that alter pharmacokinetics in unpredictable ways.
Drug interactions: Peptides may potentiate or antagonize prescription medications, herbal supplements, or other research compounds. No systematic interaction data exists for most of these molecules.
Pregnancy, lactation, and pediatric populations: Zero safety data. Absolute contraindication for use in these populations.

Legal status & buyer responsibility

The legal status of research peptides varies by country, state, and municipality. It is the buyer's sole responsibility to understand and comply with all applicable laws, regulations, and institutional policies in their jurisdiction before ordering. Dr Jays Peptides ships products with accurate customs declarations; buyers are responsible for any import duties, inspections, or seizures. We reserve the right to cancel any order where we believe the buyer lacks legitimate research intent or where shipment would violate local law.

Limitation of liability: To the maximum extent permitted by law, Dr Jays Peptides and its affiliates, suppliers, and agents disclaim all liability for any injury, illness, adverse reaction, or loss arising from the purchase, handling, or use of any product described on this page. This includes liability for negligence, product defect, mislabeling, or failure to warn. By proceeding with a purchase, you agree to indemnify and hold harmless Dr Jays Peptides from any claims, damages, or expenses related to your research activities.