Immune Support

Glutathione is a tripeptide of glutamate, cysteine, and glycine that the body produces naturally and that serves as a major intracellular antioxidant. It neutralizes reactive oxygen species and acts as a cofactor for detoxification enzymes, helping maintain cellular redox balance. It is sold as a supplement and studied in small trials for liver disease, Parkinson disease, and skin lightening, though the evidence remains limited.

How it works: It scavenges reactive oxygen species and acts as a cofactor for detoxifying enzymes, maintaining cellular redox balance.

Antioxidant support; liver disease; Parkinson disease; skin lightening; detoxification research

Chonluten is a synthetic tripeptide from the Khavinson bioregulator family, aimed at bronchial and lung tissue. Reports describe effects on stress-response, antioxidant, and inflammatory gene expression, along with uncontrolled clinical observations in chronic bronchitis in Russia. The evidence is limited and not independently replicated, and there is no Western approval.

How it works: It is proposed to modulate stress-response, antioxidant, and inflammatory gene expression in lung and bronchial cells.

Respiratory research; bronchial protection; antioxidant defense; lung aging

Real-world figures are community-reported, not medical advice.

Alpha-melanocyte-stimulating hormone is an endogenous peptide of 13 amino acids derived from proopiomelanocortin. It stimulates the melanin production that drives skin and hair pigmentation, and it also helps regulate appetite, energy balance, and inflammation through melanocortin receptors. The native peptide is not an approved medicine, although several synthetic analogues have been developed.

How it works: It activates melanocortin receptors, principally MC1R to stimulate pigment and MC3R and MC4R to influence appetite and inflammation.

Skin pigmentation; appetite regulation; inflammation modulation; energy homeostasis

Thymalin is a polypeptide complex isolated from calf thymus and used as a thymus bioregulator. It contains short peptides that are proposed to influence gene expression and promote the maturation of stem cells into T-lymphocytes, thereby modulating immune function. It has been studied for immune support in aging and, in one clinical trial, as an add-on treatment in severe COVID-19 in older patients.

How it works: It delivers thymus derived peptides thought to regulate gene expression and drive T-lymphocyte development, helping normalize immune balance.

Immune restoration; aging research; T-cell support; severe infection adjunct

Real-world figures are community-reported, not medical advice.

VIP is an endogenous peptide of 28 amino acids belonging to the secretin-glucagon family. It acts as a vasodilator, neurotransmitter, and immune modulator, and it regulates smooth muscle relaxation, glandular secretion, and circadian rhythm. Its synthetic counterpart aviptadil has been investigated for acute respiratory distress and other pulmonary conditions. VIP itself is not an approved therapy.

How it works: It binds the VPAC1 and VPAC2 receptors, raising intracellular cyclic AMP and driving vasodilation and smooth muscle relaxation.

Vasodilation; ARDS research; pulmonary hypertension research; circadian regulation

Real-world figures are community-reported, not medical advice.

Vilon is a synthetic dipeptide created in Vladimir Khavinson's laboratory and conceptually derived from thymic peptides. Animal studies report immune modulation, changes in gene expression, and, in mice, fewer spontaneous tumors and longer lifespan, while small uncontrolled human observations have been described in Russia. It is not approved by Western regulators and has no controlled clinical trials.

How it works: It is proposed to bind DNA promoter regions and remodel chromatin, influencing expression of immune-related genes such as interleukin-2.

Immune modulation; thymic support; aging research; chromatin remodeling

Real-world figures are community-reported, not medical advice.

Thymosin alpha-1, sold as Zadaxin and known generically as thymalfasin, is a 28 amino acid peptide that occurs naturally in the thymus gland. It acts as an immune modulator, strengthening T cell function and influencing innate and adaptive immunity, partly through toll-like receptor signaling. It is approved in many countries for hepatitis B and C and as an immune adjuvant, but it is not approved by the FDA in the United States.

How it works: It enhances T cell maturation and function and modulates immune signaling, including toll-like receptor pathways.

Hepatitis B; hepatitis C; immune support; cancer adjunct; vaccine adjuvant

Real-world figures are community-reported, not medical advice.

Afamelanotide is a synthetic analog of alpha-melanocyte-stimulating hormone that activates the melanocortin-1 receptor to increase protective eumelanin pigment in the skin. Marketed as the implant Scenesse, it is FDA approved to increase pain-free light exposure in adults with erythropoietic protoporphyria. It has also been researched for other light-sensitivity and pigmentation conditions such as vitiligo.

How it works: It binds and activates the melanocortin-1 receptor, stimulating protective eumelanin pigment production in the skin.

Erythropoietic protoporphyria; skin photoprotection; pigmentation disorders; vitiligo research

Icotrokinra is an orally administered peptide that selectively blocks the interleukin-23 receptor, interrupting a signaling pathway that drives the inflammation underlying plaque psoriasis. It is a once-daily pill and is notable as the first oral agent to target this receptor. The FDA approved it in March 2026 under the brand name Icotyde for adults and adolescents with moderate to severe plaque psoriasis.

How it works: It is a peptide antagonist that binds the interleukin-23 receptor, blocking IL-23 signaling that promotes inflammatory responses.

Plaque psoriasis; psoriatic disease; interleukin-23 mediated inflammation

Substance P is an endogenous eleven amino acid neuropeptide of the tachykinin family, expressed in the nervous system and immune cells. It signals mainly through the neurokinin-1 receptor and contributes to pain transmission, neurogenic inflammation, vasodilation, and immune modulation. It is used as a research tool; approved drugs in this pathway are neurokinin-1 antagonists rather than Substance P itself.

How it works: It is a tachykinin neuropeptide that activates the neurokinin-1 receptor, driving pain signaling and neurogenic inflammation.

Pain signaling research; neurogenic inflammation; NK1 receptor pharmacology; immune modulation

Zilucoplan is a synthetic macrocyclic peptide complement C5 inhibitor marketed as Zilbrysq. It received FDA approval in 2023 for generalized myasthenia gravis in adults who are anti-acetylcholine receptor antibody positive. It binds complement C5 and blocks its cleavage, limiting the terminal complement complex that damages the neuromuscular junction.

How it works: It binds complement C5 and inhibits its cleavage, preventing terminal complement complex formation at the neuromuscular junction.

Generalized myasthenia gravis; anti-AChR antibody positive disease; complement-mediated disease

LL-37 is the only human cathelicidin-derived antimicrobial peptide, a 37 amino acid molecule made by epithelial cells and various white blood cells. It disrupts the membranes of bacteria and other microbes and also shapes the innate immune response, drawing in immune cells and aiding wound repair. It has been studied mainly for infection defense, chronic wound healing, and, in small trials, as a local agent injected into melanoma.

How it works: It punctures microbial membranes and also modulates the innate immune response, recruiting immune cells and supporting tissue repair.

Antimicrobial defense; wound healing; immune modulation; melanoma research; inflammatory skin disease

Real-world figures are community-reported, not medical advice.

PNC-27 is a synthetic chimeric peptide that joins a fragment of the p53 protein to penetratin, a cell-penetrating leader sequence. It binds HDM-2 displayed in the membranes of cancer cells, where multiple copies assemble into pores that rupture the cell by necrosis while reportedly sparing normal cells. It has been examined in cultured cancer cells and animal tumor models as a possible selective anticancer agent.

How it works: It binds HDM-2 in cancer cell membranes, where copies assemble into pores that lyse the cell while largely sparing normal cells.

Anticancer research; HDM-2 targeting; tumor cell lysis; leukemia models; pancreatic cancer models

Real-world figures are community-reported, not medical advice.

Livagen is a synthetic short peptide developed within Vladimir Khavinson's bioregulator program. Published work reports that it can decondense chromatin and reactivate silenced genes in lymphocytes taken from older donors, and it is often marketed as a liver-related bioregulator. The evidence is limited to cell and laboratory studies from one research group, with no Western regulatory approval.

How it works: It is proposed to enter cells and bind DNA and histones, decondensing chromatin and reactivating silenced genes in aged cells.

Chromatin reactivation; immune cell aging; hepatic support; cellular senescence

Real-world figures are community-reported, not medical advice.

KPV is a tripeptide made of lysine, proline, and valine that corresponds to the three C-terminal residues of alpha-melanocyte-stimulating hormone. In cell and animal studies it shows anti-inflammatory activity, entering intestinal and immune cells through the PepT1 transporter and dampening inflammatory signaling. It has been studied mainly in models of colitis and is not an approved therapy.

How it works: It enters cells through the PepT1 transporter and suppresses NF-kB and MAP kinase signaling, lowering pro-inflammatory cytokine release.

Intestinal inflammation; inflammatory bowel disease; immune modulation; wound healing research

Real-world figures are community-reported, not medical advice.

ARA-290, also known as cibinetide, is an 11 amino acid peptide derived from the helix B region of erythropoietin that does not stimulate red blood cell production. It selectively activates the innate repair receptor to reduce inflammation and support nerve and tissue repair. It has been studied in phase 2 trials for sarcoidosis-associated small fiber neuropathy and diabetic neuropathic pain.

How it works: It selectively activates the innate repair receptor to reduce inflammation and promote nerve and tissue repair without stimulating red blood cells.

Neuropathic pain; tissue repair; sarcoidosis neuropathy; diabetic neuropathy; anti-inflammatory research

Real-world figures are community-reported, not medical advice.

Bronchogen is a synthetic tetrapeptide in the Khavinson bioregulator family, focused on bronchial and lung tissue. Laboratory and animal studies report effects on lung cell differentiation and on expression of genes linked to airway epithelium, mucins, and surfactant proteins. All data originate from one research group, and there is no Western approval or human trial evidence.

How it works: It is proposed to bind DNA and interact with histones, activating differentiation and secretory genes in bronchial epithelial cells.

Bronchial regeneration; respiratory research; epithelial differentiation; lung aging

Real-world figures are community-reported, not medical advice.

Thymulin, historically called serum thymic factor, is a nonapeptide produced by the thymus that requires bound zinc to become biologically active. It helps drive T-cell maturation and modulates immune and inflammatory signaling, and its activity falls with age and zinc deficiency. Thymulin is not approved by the FDA and remains a research compound, with most human data involving indirect restoration through zinc.

How it works: It is a zinc-dependent thymic nonapeptide that promotes T-cell differentiation and modulates cytokine and neuroendocrine signaling.

Immune aging; T-cell maturation; neuroinflammation research; immunodeficiency research

Real-world figures are community-reported, not medical advice.

Tat-Beclin 1 is a research peptide made of a fragment of the autophagy protein Beclin 1 fused to a cell-penetrating sequence. It induces autophagy by disrupting the interaction between Beclin 1 and a negative regulator. In laboratory and animal studies it has reduced replication of several pathogens and helped clear protein aggregates. It is an experimental tool compound with no clinical development.

How it works: It is a cell-penetrating peptide that induces autophagy by releasing Beclin 1 from its inhibitor.

Autophagy research; antiviral research; neurodegeneration models; protein-aggregate clearance

Cortistatin is a neuropeptide structurally related to somatostatin that shares most somatostatin receptor binding while also engaging the ghrelin receptor. Preclinical research associates it with modulation of slow-wave sleep, cortical activity, and suppression of inflammatory and immune responses. It is studied as an endogenous signaling molecule rather than a marketed therapy, and human data remain limited.

How it works: It binds somatostatin receptors and the ghrelin receptor, modulating neuronal excitability, cortical rhythms, and immune signaling.

Sleep and cortical rhythm research; anti-inflammatory research; autoimmune models; neuroendocrine research

IO102-IO103 is an investigational off-the-shelf therapeutic cancer vaccine developed by IO Biotech that combines peptides targeting indoleamine 2,3-dioxygenase and PD-L1. It is designed to activate T cells against tumor and immune-suppressive cells. It has been studied with checkpoint inhibitors across melanoma, head and neck, and other solid tumors, including a phase 3 melanoma trial.

How it works: It stimulates T cell responses against cells expressing IDO and PD-L1, remodeling the immunosuppressive tumor microenvironment.

Advanced melanoma; head and neck cancer; combination with checkpoint inhibitors

Motixafortide is a synthetic peptide CXCR4 antagonist marketed as Aphexda. It is FDA approved for use with filgrastim to mobilize hematopoietic stem cells into the peripheral blood for collection and autologous transplantation in patients with multiple myeloma. It disrupts the signaling axis that anchors stem cells within the bone marrow.

How it works: It antagonizes the CXCR4 receptor, blocking its ligand and releasing hematopoietic stem cells from the bone marrow into circulation.

Stem cell mobilization; combination with filgrastim; autologous transplantation in multiple myeloma

Pegcetacoplan is a pegylated peptide complement C3 inhibitor. As Empaveli it is FDA approved for paroxysmal nocturnal hemoglobinuria and certain kidney diseases, and as Syfovre it is approved as an eye injection for geographic atrophy from age-related macular degeneration. It binds C3 and C3b to regulate complement activation.

How it works: It binds complement proteins C3 and C3b, regulating their cleavage and blocking downstream complement activation.

Paroxysmal nocturnal hemoglobinuria; C3 glomerulopathy; geographic atrophy

Rusfertide is an injectable hepcidin mimetic peptide that restricts iron availability for red blood cell production. It is investigational and not FDA approved. It has been studied in the phase 2 REVIVE and phase 3 VERIFY trials for polycythemia vera, where it reduced the need for therapeutic phlebotomy and helped control hematocrit. A new drug application is under FDA priority review.

How it works: It is a synthetic mimetic of hepcidin that reduces iron availability and restrains red blood cell production, lowering hematocrit.

Polycythemia vera; erythrocytosis control; phlebotomy reduction