Immune support & longevity peptides, cross-examined.
15 immune support and longevity peptides tracked on Peptigrity, with independent HPLC purity data, shop coverage and mechanism research for each. The category covers five mechanism classes: thymic and immune-modulating peptides (Thymosin Alpha-1, VIP, KPV), telomere and aging-pathway peptides (Epithalon, NAD+ precursors), mitochondrial-targeted peptides (SS-31, ARA-290), antimicrobial and apoptotic compounds (LL-37, FOXO4-DRI, PNC-27), and erythropoietin-related compounds (EPO, Glutathione). Evidence quality varies dramatically across the category - from FDA-approved indications to preclinical-only research compounds.
Figures updated
How to choose between immune & longevity peptides
This category spans five distinct mechanism classes and a wide evidence range - from FDA-approved drugs to early-stage research compounds. Choose by the specific biological system being targeted, and treat the evidence level for each compound as a primary selection criterion.
Thymic & immune-modulating peptides
T-cell modulation, immune homeostasis, anti-inflammatory
Human RCT (Thymosin Alpha-1) · Preclinical (others)Aging-pathway peptides
Telomerase activation (Epithalon), NAD+ salvage and sirtuin support
Russian clinical (Epithalon) · Preclinical to limited clinical (NAD+)Mitochondrial-targeted peptides
Cardiolipin binding (SS-31), tissue-protective EPO receptor (ARA-290)
Human Phase 2/3 (both)Antimicrobial & apoptotic peptides
Antimicrobial activity (LL-37), senescent cell apoptosis (FOXO4-DRI), tumor cell membrane disruption (PNC-27)
PreclinicalErythropoietin & antioxidant compounds
EPO (Erythropoietin), Glutathione
Red blood cell stimulation (EPO), antioxidant and detoxification (glutathione)
Human RCT (EPO) · Limited (glutathione peptide form)Compounds in this category
Immune Support & Longevity prices →| Compound | Avg purity | Lab tests | Shops listing it |
|---|---|---|---|
NAD+Not a peptide Nicotinamide adenine dinucleotide, a coenzyme essential for cellular energy metabolism, DNA repair, and sirtuin activation. Researched for aging and metabolic health. | 99.1% | 374 | 495 |
Synthetic tetrapeptide (Ala-Glu-Asp-Gly) researched for telomerase activation, telomere elongation, and potential anti-aging effects. | 99.4% | 281 | 415 |
Anti-inflammatory tripeptide from α-MSH researched for gut health, skin barrier repair, and NF-κB inhibition. | 99.6% | 281 | 428 |
Mitochondria-targeted tetrapeptide researched for restoring cellular energy production, reducing oxidative stress, and treating mitochondrial dysfunction. | 99.7% | 245 | 341 |
Thymic peptide researched for immune modulation, T-cell activation, and antiviral response. Approved in over 35 countries as Zadaxin® for hepatitis B. | 99.5% | 240 | 355 |
| 99.5% | 143 | 352 | |
Synthetic 11-amino acid peptide derived from erythropoietin (EPO), researched for neuroprotection, tissue repair, and anti-inflammatory effects without erythropoiesis. | 98.7% | 97 | 268 |
28-amino-acid neuropeptide researched for immune regulation, neuroprotection, and circadian rhythm modulation. | 99.4% | 78 | 247 |
The only human cathelicidin antimicrobial peptide with broad-spectrum activity against bacteria, viruses, and fungi. | 99.4% | 64 | 245 |
| 99.4% | 61 | 185 | |
Anticancer research peptide that selectively targets membrane-associated HDM-2 on tumor cells, inducing membranolysis without affecting normal cells. | 99.6% | 15 | 131 |
A zinc-dependent thymic nonapeptide hormone (formerly "FTS") produced by thymic epithelial cells, researched for T-cell differentiation, immune modulation, and age-related immune decline. | 99.2% | 5 | 24 |
EPO (Erythropoietin)Not a peptide Glycoprotein hormone that stimulates red blood cell production (erythropoiesis). FDA-approved for anemia treatment. Known for endurance performance effects. | 99.5% | 1 | 86 |
A 24-amino-acid mitochondrial-derived peptide — the first of its class to be discovered — researched for anti-apoptotic cytoprotection, neuroprotection, and insulin sensitivity. | 99.2% | 1 | 40 |
| No lab tests yet · 1 compound | |||
Growth differentiation factor 11 — a TGF-β-superfamily protein and close homologue of myostatin, studied as a circulating "rejuvenation factor" for heart, brain, and muscle aging, though its anti-aging role remains scientifically contested. | — | Submit one → | 4 |
Lab tests link to each compound's lab-test page. Purity dots: ≥98% green · 95–98% purple · 90–95% amber · under 90% red (the /lab-tests bands). “Shops listing it” counts shops that list the compound, tested or not.
Mechanism overview
Thymic peptides act on T-cell development and immune homeostasis. The thymus produces multiple immunoregulatory peptides during T-cell maturation; Thymosin Alpha-1 is the most-studied of these and the only one in this category with substantial clinical evidence. Tα1 modulates T-cell function, particularly toward Th1-biased responses, supporting clearance of intracellular pathogens. VIP and KPV act through different immune pathways - VIP through GPCR signaling on multiple immune cell types, KPV through NF-κB inhibition.
Aging-pathway peptides target the molecular hallmarks of aging directly. Epithalon is the most-studied telomerase activator with documented effects in Russian clinical research on telomere length and aging biomarkers. The compound's mechanism in Western preclinical research is less fully characterized than the Russian clinical evidence implies - replication is ongoing. NAD+ is essential for sirtuin function, DNA repair via PARP, and mitochondrial energy metabolism; declining NAD+ levels are documented across aging and several disease states.
Mitochondrial-targeted peptides take a fundamentally different approach. Rather than upstream pathway activation, they directly stabilize mitochondrial function. SS-31 binds cardiolipin in the inner mitochondrial membrane, supporting electron transport chain efficiency and reducing reactive oxygen species generation. ARA-290 binds the innate repair receptor (a heteroreceptor distinct from the canonical EPO receptor), producing tissue-protective effects without erythropoiesis. Both have moved through significant Western clinical development.
The antimicrobial and apoptotic peptides operate through cytotoxic mechanisms specific to particular cell types. LL-37 disrupts pathogen membranes preferentially over host cells. FOXO4-DRI exploits a specific protein interaction (FOXO4-p53) that senescent cells rely on to escape apoptosis. PNC-27 targets HDM-2 on the surface of tumor cells, where healthy cells do not display it. Selectivity is the key feature of all three.
Erythropoietin and glutathione round out the category through different biology - RBC production support and antioxidant function respectively.
For deeper background on peptide manufacturing and verification, see how peptides are made.
⚠ Quality verification: this category has the widest evidence range on Peptigrity
Verification dimensions vary substantially across this category:
LARGE-MOLECULE COMPOUNDS REQUIRE RECOMBINANT PRODUCTION: Thymosin Alpha-1, EPO, VIP, and similar mid-to-large peptides cannot be produced reliably by solid-phase synthesis at the lengths required (28-165 amino acids). These require recombinant expression with proper post-translational modification. Synthetic short-peptide vendors generally cannot produce active forms. Verify the source clearly states recombinant production for these compounds.
GLUTATHIONE FORM CLARIFICATION: Glutathione is sold as reduced (GSH), oxidized (GSSG), or as injectable/IV preparations. The forms have different shelf life and bioavailability. The reduced form is what's typically researched - verify which form a vendor is shipping via mass spectrometry.
EPITHALON SHORT-PEPTIDE COUNTERFEITING: Epithalon is a four-amino-acid peptide, easy to mis-synthesize or substitute. Mass spectrometry identity verification is essential. The compound's purity threshold of ≥98% is achievable but not universal across vendors.
THIN INDEPENDENT DATA FOR EARLY-STAGE COMPOUNDS: FOXO4-DRI, PNC-27, P21, VIP, and several others have very few verified lab tests on Peptigrity. For those compounds, the absence of test data is itself information - fewer independent checks means more vendor trust required and more buyer risk.
Frequently asked questions
EPO (erythropoietin) is FDA-approved as Procrit and Epogen for anemia treatment in specific medical contexts. Thymosin Alpha-1 is approved in over 35 countries (including most of Europe) as Zadaxin for hepatitis B and hepatitis C, but does not currently have FDA approval in the United States. SS-31 (elamipretide) is in active Phase 3 development but not yet approved. The other 9 compounds in this category are research compounds or supplements without FDA drug approval. Glutathione is sold as a supplement in many forms, regulated under DSHEA rather than as a drug.
Epithalon was developed by the same Vladimir Khavinson research program that produced the Khavinson bioregulators (Thymalin, Pinealon, Vilon, etc.). Historically, it could be grouped either way. Peptigrity tracks it separately under Immune Support & Longevity because its primary research focus - telomerase activation and telomere length effects - is distinct enough from the organ-specific bioregulator framework to warrant separate treatment. The compound is sometimes informally called a "fifth-generation bioregulator" but its evidence base and Western recognition as a telomerase research compound are both stronger than for most other Khavinson peptides.
SS-31 has had sustained pharmaceutical development by Stealth Biotherapeutics, with Phase 2 and Phase 3 trials for specific mitochondrial diseases (primary mitochondrial myopathy, Barth syndrome). The mechanism - cardiolipin binding to support electron transport chain function - is well-characterized and disease-relevant for those indications. ARA-290 (cibinetide) has had similar pharmaceutical development through Araim Pharmaceuticals. Both compounds occupy a position closer to investigational pharmaceuticals than to generic research peptides - which has implications for both quality (regulated manufacturing exists) and pricing (substantially higher than typical research peptides).
Long-term safety in humans has not been characterized. FOXO4-DRI specifically is a research compound studied primarily in mouse models of aging - published animal data shows clearance of senescent cells in several tissues, with apparent improvements in age-related markers. There is no human clinical trial data sufficient to characterize safety, optimal dosing, or long-term effects. The compound's mechanism - selective apoptosis induction in senescent cells - is theoretically clean, but "senescent cell" identification is not always sharp at the single-cell level, and unintended effects in stem cell or progenitor populations have not been ruled out. Treat as preclinical-only research.
EPO is FDA-approved for legitimate medical contexts (anemia in chronic kidney disease, chemotherapy-induced anemia) and prescribed by physicians for those indications. It is also extensively used non-medically for endurance performance enhancement, which is illegal in WADA-tested sports (prohibited under class S2) and carries serious cardiovascular risks - including thrombosis, hypertension, and rare but documented sudden cardiac death cases linked to performance-enhancement use. Peptigrity is an educational platform and does not provide guidance on non-medical EPO use. Anyone using EPO outside a prescription context should understand the documented mortality risk associated with non-medical use.
Dosing varies dramatically across this category, more than in any other category on Peptigrity. Some compounds (Thymosin Alpha-1) are dosed in milligrams; others (Epithalon, SS-31) in lower microgram ranges; oral or intranasal administration applies to some (NAD+ precursors, glutathione in some forms) but not most. Use the general peptide calculator for any compound, plus the BAC water calculator for reconstitution. Compound-specific protocols differ - read each individual compound page above for research-reported ranges.
This article is for educational and informational purposes only and does not constitute medical advice. Peptides discussed may be investigational compounds not approved by the FDA (or equivalent regulators in your jurisdiction) for human use. Always consult a qualified healthcare provider before using any peptide or research compound. Peptigrity is an independent review platform and does not sell, endorse, or recommend specific products or vendors.