Elamipretide (MTP-131) is a mitochondria-targeted antioxidant tetrapeptide (D-Arg-dimethylTyr-Lys-Phe-NH2) that reduces toxic reactive oxygen species (ROS) production and stabilizes cardiolipin, with blood-brain-barrier permeability. Elamipretide is a potential therapeutic agent in the rare disease of Barnes syndrome.

TAT-Gap19 acetate is a specific inhibitor of connexin43 hemichannel (Cx43 HC). TAT-Gap19 acetate traverses the blood-brain barrier and alleviates liver fibrosis in mice. TAT-Gap19 acetate does not inhibit the corresponding Cx43 GJCs.

Carbetocin is an obstetric drug used to control postpartum hemorrhage and bleeding after giving birth.

γ-Fibrinogen377-395 TFA is an inhibitory peptide derived from fibrinogen, which also functions as a fibrinogen epitope. It effectively blocks microglial activation and impedes fibrin-Mac-1 interactions in vitro. Additionally, it exhibits in vivo efficacy by suppressing experimental autoimmune encephalomyelitis (EAE) in mice. This compound has applications in researching multiple sclerosis (MS) and other neuroinflammatory diseases linked to blood-brain barrier disruption and microglial activation [1].

Galanin-B2 (NAX-5055) demonstrates activity in epilepsy models and possesses the ability to penetrate the blood-brain barrier [1].

TAT-Gap19 TFA, a Cx mimetic peptide and specific connexin43 hemichannel (Cx43 HC) inhibitor, does not inhibit the corresponding Cx43 gap junction channels (GJCs). It crosses the blood-brain barrier and has been shown to alleviate liver fibrosis in mice [1] [2] [3].

HAIYPRH hydrochloride is a targeting ligand that specifically binds to the transferrin receptor (TfR) and facilitates the transport of nanocarriers across the blood-brain barrier [1].

Type A Allatostatin III (allatostatin 3), a neuropeptide that can cross the blood-brain barrier and is reversible, suppresses hormone production in juvenile female cockroaches. This compound has applications in pesticide research [1].

GluN1 (359-378) is an antibody targeting the N-methyl-D-aspartate receptor (NMDAR) capable of crossing the blood-brain barrier and is utilized in researching therapies for anti-NMDAR encephalitis that focus on the immune system [1].

Substance P (3-11), an SP fragment peptide capable of crossing the blood-brain barrier (BBB), induces contraction in guinea pig ileum and facilitates chemotaxis in human monocytes [1] [2] [5].

Relamorelin (RM-131) acetate is a pentapeptide ghrelin analog that acts as a selective agonist for the ghrelin/growth hormone secretagogue receptor (GHSR). It exhibits a high affinity for the GHS-1a receptor, with a Ki value of 0.42 nM. Notably, Relamorelin acetate can cross the blood-brain barrier and target the central nervous system. This compound effectively increases growth hormone levels and promotes faster gastric emptying. Due to these properties, Relamorelin acetate holds promise for its potential applications in research related to cachexia, gastroparesis, and gastric/intestinal dysmobility disorders [4] [5].

γ-Fibrinogen377-395 is a peptide derived from fibrinogen, functioning both as an inhibitory molecule and an epitope. It inhibits microglial activation, disrupts fibrin-Mac-1 interactions in vitro, and mitigates experimental autoimmune encephalomyelitis (EAE) in murine models in vivo. This compound is relevant for research into multiple sclerosis (MS) and other neuroinflammatory disorders characterized by blood-brain barrier compromise and microglial activation [1].

Phoenixin-14 TFA (PNX-14) is a blood-brain barrier (BBB)-penetrable neuropeptide with anxiolytic, cardioprotective, and neuroprotective properties. It modulates pituitary gonadotrophin release by enhancing gonadotropin-releasing hormone (GnRH) receptor mRNA expression and promotes insulin secretion. Additionally, PNX-14 TFA offers protection against ischemia/reperfusion (IR) injury in mice and combats oxidative stress by diminishing reactive oxygen species (ROS) and elevating glutathione (GSH) levels [1] [2] [3].

Pegsebrenatide (NLY01), a long-acting GLP-1R agonist, exhibits an extended half-life and favorable blood-brain barrier penetration. It impedes A1 astrocyte transformation, mitigates dopaminergic cell death, and ameliorates motor symptoms in mouse models of Parkinson's disease (PD) [1].

Angiopep-Bim BH3 hydrochloride, a peptode that penetrates the blood-brain barrier (BBB), may serve as a tool to study the permeability of central nervous system (CNS) therapeutics [1].

Rabies Virus Glycoprotein (TFA) is a kind of by the Rabies Virus Glycoprotein 29 - amino acid derived cell penetrating peptides, it can pass the blood brain barrier (BBB) into the brain cells.

Orexin A (Hypocretin-1) (human, rat, mouse) acetate, a hypothalamic neuropeptide with analgesic abilities that penetrates the blood-brain barrier, acts as an OX1R agonist. It promotes the expression of BDNF and TH proteins within SH-SY5Y cells, showing both time- and dose-dependent responses. This compound is valuable for researching appetite control, neurodegenerative conditions, and the modulation of detrimental signaling [1] [2] [3].

Certain chronic neurologic disorders, such as Parkinson's disease, are caused by an insufficiency of the neurotransmitter dopamine secondary to the degeneration of substantia nigra dopaminergic neurons. N-(α-Linolenoyl) tyrosine (NALT) is a simple α-amide conjugate between the ω-3 essential fatty acid α-linolenate and the amino acid tyrosine. α-Linolenate is an important precursor to docosahexaenoic acid (DHA), a prominent brain polyunsaturated fatty acid, while tyrosine is the metabolic precursor for neuronal dopamine synthesis. NALT was prepared as a method for enhancing central nervous system (CNS) dopamine content by facilitated transport of the tyrosine precursor across the blood-brain barrier. In experimental rat models of dopamine insufficiency, NALT increased CNS dopamine levels and exhibited an activity profile consistent with an anti-Parkinson's therapeutic agent.

Tat-QFNP12 is a peptide that combines a transcriptional transactivator (Tat) transmembrane domain with an inhibitor targeting the interaction between N-Myc downstream regulated gene 2 (NDRG2) and protein phosphatase Mg2+/Mn2+ dependent 1A (PPM1A). This compound effectively mitigates blood-brain barrier endothelial tight junction disruption caused by elevated levels of matrix metalloproteinase-9 (MMP-9), alleviates cerebral edema, and promotes spontaneous activity along with symmetric limb movement in a mouse model of subarachnoid hemorrhage induced by endovascular puncture. These benefits are observed at a dosage of 20 mg/kg.

Relamorelin (RM-131) TFA, a pentapeptide ghrelin analog, acts as a potent and selective agonist for the ghrelin/growth hormone secretagogue receptor (GHSR), with a K_i of 0.42 nM for the GHS-1a receptor. This compound is capable of crossing the blood-brain barrier and effectively increases growth hormone levels while promoting faster gastric emptying. It holds significant research potential for conditions such as cachexia, gastroparesis, and disorders related to gastric/intestinal motility [1] [2] [3] [4] [5].

CTAP TFA, a potent and highly selective μ opioid receptor antagonist that effectively crosses the blood-brain barrier, exhibits a significant inhibition concentration (IC50) of 3.5 nM. It demonstrates extraordinary selectivity, being over 1200-fold more specific to μ opioid receptors than to δ opioid (IC50 = 4500 nM) and somatostatin receptors. This compound is primarily leveraged for researching L-DOPA-induced dyskinesia (LID) and opiate overdose or addiction [1] [2].

Cyclotraxin B TFA, a cyclic peptide, serves as a highly potent and selective non-competitive inhibitor of TrkB, effectively impeding BDNF-triggered TrkB activity without altering BDNF binding affinity, evidenced by an IC50 of 0.30 nM. It is capable of crossing the blood-brain barrier, demonstrating analgesic and anxiolytic-like behavioral effects [1] [2] [3].

TfR-T12 is a transferrin receptor (TfR) binding peptide that can penetrate the blood-brain barrier (BBB), exhibiting a high binding affinity within the nanomolar (nM) range.

TAT-NEP1-40 TFA, a blood-brain barrier-permeable peptide, safeguards PC12 cells against oxygen and glucose deprivation (OGD) and fosters neurite outgrowth. Additionally, it enhances neurological outcomes post-ischemia by curtailing apoptosis in ischemic cerebral tissues. This compound has utility in investigating central nervous system (CNS) injuries, encompassing axonal regeneration and functional recuperation following a stroke [1].

SARS-CoV-2-IN-34 (S-20-1) is a broad-spectrum pan-coronavirus (CoV) fusion inhibitor capable of penetrating the blood-brain barrier and demonstrating extensive inhibitory activity against both pseudotyped and authentic SARS-CoV-2, as well as pseudotyped variants of concern (VOCs). It exhibits high affinity for the receptor-binding domain (RBD) in the S1 and the heptad repeat 1 (HR1) domain in the S2 of the SARS-CoV-2 spike (S) protein, making it a valuable tool for infection research [1].

Biphalin TFA is an opioid peptide analog that penetrates the blood-brain barrier (BBB) and encompasses two active enkephalin pharmacophores. It exhibits high affinity for opioid receptors and demonstrates analgesic effects in acute, neuropathic, and chronic animal pain models. Additionally, Biphalin TFA possesses antiviral, antiproliferative, anti-inflammatory, and neuroprotective properties [1].

TfR-T12 TFA, a transferrin receptor (TfR)-binding peptide capable of crossing the blood-brain barrier (BBB), exhibits nanomolar (nM) binding affinity [1] [2].

NNZ 2591, a synthetic analogue of cyclic glycine-proline (cGP), exhibits oral activity and the ability to cross the blood-brain barrier. This compound demonstrates neuroprotective properties following ischemic brain injury and improves motor function in a rat model of Parkinson's disease. NNZ 2591 holds research potential for ischemic brain injury and Angelman syndrome [1] [2] [3].

Epobis, a dendrimeric peptide and recombinant form of erythropoietin, acts as a potent erythropoietin receptor agonist. It fosters neuritogenesis in primary motoneurons, reduces TNF release, and effectively crosses the blood-brain barrier. Additionally, Epobis exhibits anti-inflammatory properties and enhances memory [1].

MIF-1 TFA (Melanostatin), an intrinsic brain peptide, serves as a powerful allosteric modulator of the dopamine receptor. It plays a crucial role in regulating melanin production and modifies the analgesic efficacy by inhibiting the opioid receptor's effects. Significantly, MIF-1 TFA can cross the blood-brain barrier (BBB) directly, facilitating its access from the bloodstream to the central nervous system (CNS) [1] [2] [3].

Nemifitide diTFA (INN 00835 diTFA) is a synthetic pentapeptide, a peptide like melanocyte suppressor factor (MIF) that can cross the blood-brain barrier and has potent antidepressant activity.

TAT-NEP1-40, a blood-brain barrier (BBB) permeable peptide, confers protection to PC12 cells against oxygen and glucose deprivation (OGD) while promoting neurite outgrowth. Furthermore, it enhances neurologic outcomes post-ischemia by mitigating apoptosis in affected cerebral regions. This compound holds potential for central nervous system (CNS) injury research, including studies on axonal regeneration and post-stroke functional recovery [1].

BH3 hydrochloride, a peptide that crosses the blood-brain barrier, induces apoptosis either through direct activation of the pro-apoptotic proteins Bax/Bak or by inhibiting anti-apoptotic Bcl-2 proteins (Bcl-2, Bcl-XL, Bcl-w, Mcl-1, and A-1) through their BH3 domain [1][2].

Carbetocin acetate is an obstetric drug used to control postpartum hemorrhage and bleeding after giving birth.