Peptide Therapy Guide

CagriSema is Novo Nordisk's fixed-dose combination of cagrilintide (a long-acting amylin analog) and semaglutide (GLP-1 agonist), submitted to the FDA for approval in December 2025 with a decision expected in late 2026. In the REDEFINE 1 Phase 3 trial, CagriSema produced 20.4% mean weight loss over 68 weeks — exceeding semaglutide monotherapy by pairing two distinct satiety pathways. It is the first once-weekly amylin + GLP-1 combination targeting obesity.

Orforglipron (brand name Foundayo) is Eli Lilly's once-daily oral GLP-1 receptor agonist, FDA-approved in May 2026 for chronic weight management and type 2 diabetes. Unlike semaglutide (Rybelsus), orforglipron is a small-molecule non-peptide GLP-1 agonist — meaning it does not require refrigeration, injection, or food-timing restrictions. Phase 3 trials demonstrated 12.4% mean weight loss over 72 weeks, making it the first oral GLP-1 to approach injectable-level efficacy.

Retatrutide (LY3437943) is Eli Lilly's investigational triple-agonist peptide that simultaneously activates GLP-1, GIP, and glucagon receptors. In the Phase 2 TRIUMPH trial, participants on the highest dose lost an average of 24.2% of body weight over 48 weeks, with some Phase 3 cohorts reporting losses above 28%. Expected to file an NDA with the FDA in Q4 2026, retatrutide is widely anticipated to become the next major advance beyond tirzepatide for obesity and metabolic disease.

Semaglutide is a GLP-1 receptor agonist originally developed for type 2 diabetes that has shown remarkable effectiveness for weight management. Sold under brand names Ozempic (for diabetes) and Wegovy (for weight loss), it works by mimicking a natural hormone that regulates appetite and food intake. Clinical trials have demonstrated average weight loss of 15-20% of body weight over 68 weeks.

Tirzepatide is a dual GIP/GLP-1 receptor agonist marketed as Mounjaro (for diabetes) and Zepbound (for weight loss). It is the first medication to activate both incretin hormone receptors simultaneously, leading to superior weight loss results compared to GLP-1-only medications. Clinical trials showed average weight loss of up to 22.5% of body weight.

5-Amino-1MQ is a small-molecule inhibitor of nicotinamide N-methyltransferase (NNMT), an enzyme involved in fat cell metabolism and NAD+ regulation. It is not a peptide, though it is sold alongside them. Interest comes from preclinical work in which NNMT inhibition reduced fat mass in obese mice. There are no completed human clinical trials, and it is not approved for any use.

AOD-9604 is a modified fragment of human growth hormone (amino acids 177-191) that was developed specifically for fat metabolism. Unlike full HGH, it does not affect blood sugar levels or cause growth. It stimulates lipolysis (fat breakdown) and inhibits lipogenesis (fat formation) without the negative effects associated with growth hormone therapy.

Cagrilintide is a long-acting analog of amylin, a hormone co-secreted with insulin by pancreatic beta cells that promotes satiety and slows gastric emptying. Developed by Novo Nordisk, cagrilintide is being studied both as a standalone weight-management therapy and as the amylin component of the CagriSema combination. As monotherapy in Phase 2 trials, cagrilintide 2.4 mg weekly produced approximately 10.8% mean weight loss over 26 weeks — competitive with older GLP-1 agents.

Liraglutide is a once-daily GLP-1 receptor agonist and the first drug in its class approved for chronic weight management. It was approved as Victoza for type 2 diabetes in 2010 and as Saxenda for weight management in 2014, several years before semaglutide. Because it is dosed daily rather than weekly and produces less weight loss than the newer agents, it has largely been displaced by semaglutide and tirzepatide — but it remains FDA-approved, and generic versions began reaching the US market in 2024, which can make it substantially cheaper than the branded weekly drugs.

Mazdutide is a dual GLP-1 and glucagon receptor agonist licensed by Innovent Biologics from Eli Lilly. It was approved in China in 2025 for weight management, making it one of the first glucagon co-agonists approved anywhere. It is not FDA-approved and is not legally available in the United States. US readers encountering it online should understand that no domestic supply route is lawful.

Survodutide is an investigational dual agonist of the GLP-1 and glucagon receptors, developed by Boehringer Ingelheim with Zealand Pharma. Adding glucagon receptor activity to GLP-1 is intended to raise energy expenditure as well as suppress appetite, a different strategy from tirzepatide's GIP/GLP-1 combination. It is in phase 3 trials for obesity and has also been studied in MASH. It is not approved anywhere and cannot be legally prescribed or sold.

Tesamorelin (brand name Egrifta) is a growth hormone-releasing hormone (GHRH) analog FDA-approved for reducing excess abdominal fat in HIV-positive patients with lipodystrophy. It stimulates the pituitary gland to produce natural growth hormone, which in turn promotes fat metabolism. It is increasingly used off-label for general visceral fat reduction and anti-aging purposes.

Tesofensine is a triple monoamine reuptake inhibitor — it blocks reuptake of dopamine, noradrenaline and serotonin — originally developed for Parkinson's and Alzheimer's disease, where it failed, and later repurposed for obesity after weight loss was noticed as a side effect. It is not a peptide, despite frequently appearing on peptide vendor sites. It has completed phase 3 obesity trials and is not FDA-approved.

BPC-157 (Body Protection Compound-157) is a synthetic peptide derived from a protein found naturally in human gastric juice. It has shown remarkable healing properties in preclinical studies, demonstrating the ability to accelerate wound healing, repair tendons, ligaments, muscles, and the gut lining. It is one of the most widely used peptides in sports medicine and functional medicine.

TB-500 is a synthetic version of Thymosin Beta-4, a naturally occurring peptide present in virtually all human and animal cells. It plays a crucial role in tissue repair, cell migration, and the formation of new blood vessels. TB-500 is widely studied for its ability to promote healing across multiple tissue types, including muscle, tendon, ligament, skin, heart, and eye tissue.

Delta sleep-inducing peptide (DSIP) is a nonapeptide first described in 1977, isolated from the cerebral venous blood of rabbits during induced sleep. It has been studied for sleep regulation, stress response and pain, but the evidence base is small, old, and largely unreplicated. It has no approved medical use in any country.

KPV is a tripeptide (Lys-Pro-Val) derived from alpha-melanocyte stimulating hormone (α-MSH). It is a potent anti-inflammatory peptide that has shown promise in treating inflammatory bowel disease, skin conditions, and general systemic inflammation. KPV can be administered via injection, orally, or topically, making it versatile for various applications.

GHK-Cu (copper peptide) is a naturally occurring tripeptide with a high affinity for copper ions. Present in human plasma, saliva, and urine, its concentration declines significantly with age. GHK-Cu has been extensively studied for its remarkable regenerative and protective properties, including skin remodeling, wound healing, anti-inflammatory activity, and antioxidant effects.

MOTS-c (Mitochondrial Open Reading Frame of the 12S rRNA-c) is a 16-amino-acid peptide encoded within mitochondrial DNA — one of the few known mitochondrial-derived peptides with systemic hormonal effects. Discovered in 2015 at USC, MOTS-c acts as an exercise mimetic, improving metabolic flexibility, insulin sensitivity, and skeletal muscle function. Circulating MOTS-c declines sharply with age, and supplementation has become a pillar of longevity-focused peptide protocols alongside NAD+ and epithalon.

NAD+ (Nicotinamide Adenine Dinucleotide) is a coenzyme found in all living cells that plays a critical role in energy metabolism, DNA repair, and cell signaling. NAD+ levels naturally decline with age, and this decline is associated with numerous age-related diseases. NAD+ therapy, delivered via IV infusion or subcutaneous injection, aims to restore youthful NAD+ levels.

SS-31, known clinically as elamipretide (brand name Forzinity), is the first FDA-approved mitochondrial-targeted peptide. Approved in September 2025 for Barth syndrome — a rare genetic mitochondrial disease — elamipretide selectively binds to cardiolipin in the inner mitochondrial membrane, stabilizing the electron transport chain and reducing reactive oxygen species. Off-label interest in SS-31 has surged among longevity clinics for age-related mitochondrial dysfunction, heart failure with preserved ejection fraction, and neurodegenerative conditions.

Epithalon (also known as Epitalon or Epithalone) is a synthetic tetrapeptide based on a natural peptide called Epithalamin, which is produced by the pineal gland. It is primarily studied for its ability to activate telomerase, the enzyme responsible for maintaining telomere length — a key factor in cellular aging. Research suggests it may have life-extending properties.

CJC-1295 is a synthetic analog of growth hormone-releasing hormone (GHRH) that has been modified to have a longer half-life than natural GHRH. Often combined with DAC (Drug Affinity Complex) for extended activity, it is frequently paired with Ipamorelin for synergistic growth hormone release. CJC-1295 stimulates consistent, elevated GH levels without the spikes associated with direct HGH injection.

Gonadorelin is a synthetic analog of gonadotropin-releasing hormone (GnRH) used in modern testosterone replacement therapy (TRT) protocols to preserve testicular function, fertility, and endogenous hormone signaling. It has largely replaced human chorionic gonadotropin (hCG) in compounded TRT practice following FDA supply and regulatory changes. Gonadorelin stimulates the pituitary to release LH and FSH, which in turn maintain intratesticular testosterone production and spermatogenesis during exogenous testosterone therapy.

Ipamorelin is a selective growth hormone secretagogue that stimulates the pituitary gland to release growth hormone. It is considered one of the safest and most well-tolerated growth hormone peptides because it does not significantly increase cortisol or prolactin levels. It is frequently combined with CJC-1295 for enhanced and sustained growth hormone release.

Sermorelin is a growth hormone-releasing hormone (GHRH) analog that stimulates the pituitary gland to produce and release natural growth hormone. Unlike direct HGH supplementation, Sermorelin works with the body's natural feedback mechanisms, making it a safer alternative for growth hormone optimization. It was FDA-approved for use in growth hormone-deficient children. Its US approval as Geref was withdrawn in 2009, and it is no longer available as an FDA-approved product; the sermorelin prescribed today is supplied by compounding pharmacies.

GHRP-2 (Growth Hormone Releasing Peptide-2) is a synthetic growth hormone secretagogue that stimulates the pituitary gland via the ghrelin receptor. It is considered more potent than GHRP-6 for GH release but with a somewhat less pronounced appetite-stimulating effect. Like other GHRPs, it is often used in combination with GHRH analogs.

GHRP-6 (Growth Hormone Releasing Peptide-6) is a synthetic hexapeptide that stimulates growth hormone release by acting on the ghrelin receptor. It is one of the earlier GH-releasing peptides developed and is known for its potent appetite-stimulating effects alongside GH release. It is often used in combination with GHRH analogs for synergistic effects.

Hexarelin is a synthetic hexapeptide growth hormone secretagogue in the GHRP family, related to GHRP-6 and ipamorelin. It stimulates growth hormone release through the ghrelin receptor and has also been studied for direct effects on cardiac tissue. It is not approved for any human use. A recognised limitation is that its growth hormone response attenuates with continued administration.

IGF-1 LR3 (Long R3 IGF-1) is a modified form of insulin-like growth factor 1, altered so that it binds far less to the IGF binding proteins that normally carry the hormone in circulation. It was developed as a laboratory reagent for cell culture, not as a human therapeutic, and it is not approved for human use anywhere. It is widely claimed online to last far longer than natural IGF-1. That has the pharmacology backwards: binding proteins are what prolong native IGF-1, so binding them less leaves more hormone immediately free and more potent in laboratory models, while animal work found it cleared from plasma faster than native IGF-1, not slower.

Dihexa is a synthetic analogue of angiotensin IV developed at Washington State University and studied in preclinical neurodegeneration research. It has not entered human clinical trials and is not approved for any use. Its proposed mechanism - potentiating hepatocyte growth factor and its receptor c-Met to promote synapse formation - should be treated with real caution: the 2014 Journal of Pharmacology and Experimental Therapeutics paper that established that mechanism was retracted in April 2025, which removes the main published support for how this compound was said to work.

Selank is a synthetic heptapeptide derived from the immune peptide tuftsin, developed at the Institute of Molecular Genetics in Russia. It is registered as an anxiolytic in Russia but has never been reviewed or approved by the FDA, and the clinical literature supporting it is almost entirely Russian-language and difficult to appraise against Western trial standards.

Semax is a synthetic heptapeptide derived from ACTH(4-10), developed in Russia and approved there for stroke and cognitive indications. It is not approved by the FDA for any use in the United States. Its mechanism work — increasing BDNF and TrkB expression in the brain — is well documented in preclinical studies, while its clinical trial literature is largely Russian-language and has not been independently replicated in English-language journals. In July 2026 an FDA advisory committee recommended Semax for the 503A bulks list; a recommendation is advisory and did not change its legal status.

PT-141 (Bremelanotide, brand name Vyleesi) is a melanocortin receptor agonist FDA-approved for the treatment of hypoactive sexual desire disorder (HSDD) in premenopausal women. Unlike other sexual dysfunction treatments that act on the vascular system, PT-141 works through the central nervous system, specifically the melanocortin receptors in the brain that regulate sexual arousal and desire.

LL-37 is the only cathelicidin-derived antimicrobial peptide found in humans. It is a key component of the innate immune system and is produced by various cell types including neutrophils, macrophages, and epithelial cells. LL-37 has broad-spectrum antimicrobial activity against bacteria, viruses, and fungi, and also plays important roles in wound healing and immune modulation.

Thymosin Alpha-1 (brand name Zadaxin) is a naturally occurring peptide produced by the thymus gland that plays a critical role in immune system regulation. It is approved in over 35 countries for the treatment of hepatitis B and C and as an immune adjuvant. It enhances the function of T-cells, natural killer cells, and dendritic cells, making it valuable for immune optimization. It is not approved by the FDA in the United States, and approval elsewhere is not FDA review. FDA placed thymosin alpha-1 in Category 2 in 2023, and removal from that category in 2026 does not by itself authorise compounding.