Peptide Glossary
Complete A-Z index of research peptides with scientific data, categories, and links to detailed profiles.
0–9
A
Cosyntropin is a synthetic version of the first 24 building blocks of the body's natural stress hormone ACTH. It is used as an FDA-approved diagnostic tool (Cortrosyn) to test whether the adrenal glands are working properly, and is also used to treat certain conditions like infantile spasms.
AHK-Cu (Copper Tripeptide-3) is a synthetic copper peptide designed specifically to target hair follicle cells. Unlike the naturally occurring GHK-Cu, AHK-Cu was engineered to stimulate hair growth by extending the active growth phase of the hair cycle and increasing follicle cell activity. It is applied topically to the scalp.
AOD-9604 is a modified fragment of human growth hormone (amino acids 176-191). Originally developed as an anti-obesity compound, it shows preclinical evidence for promoting fat metabolism without affecting blood sugar or growth.
ARA-290 (cibinetide) is a synthetic 11-amino-acid peptide based on the tissue-protective part of erythropoietin, without stimulating red blood cell production. Research focuses on nerve pain, small fiber neuropathy, sarcoidosis, and metabolic syndrome.
Argireline is a synthetic six-amino-acid peptide widely used in cosmetic skincare as a topical alternative to botulinum toxin injections. It works by partially blocking the nerve signaling pathway involved in muscle contractions, reducing the intensity of facial movements and softening expression lines around the eyes and forehead.
B
C
CJC-1295 without DAC (also called Modified GRF 1-29) is a synthetic growth hormone-releasing compound with a short active window of about 30 minutes. It is being studied for its effects on growth hormone release and body composition.
CJC-1295 with DAC (Drug Affinity Complex) is a long-acting growth hormone-releasing compound that binds to a blood protein called albumin, extending its active life to several days. This provides sustained growth hormone elevation compared to the shorter-acting Mod GRF 1-29.
Cerebrolysin is a preparation derived from pig brain tissue containing small brain-protective peptides and amino acids. It is approved in many countries (but not the United States) for stroke, traumatic brain injury, and dementia. It is one of the most extensively studied brain peptide formulations.
Cortagen is a synthetic four-amino-acid peptide that may help regulate brain cortex function. Developed at the St. Petersburg Institute of Bioregulation and Gerontology, research focuses on supporting cognitive function in aging and protecting brain cells.
D
DSIP (Delta Sleep Inducing Peptide) is a naturally occurring brain peptide first isolated from rabbit brain tissue. Research focuses on sleep promotion, stress reduction, and hormone regulation. It shows complex effects that vary depending on the context.
Dihexa is a synthetic six-amino-acid peptide related to angiotensin IV with strong cognitive-enhancing properties. It has been proposed to be millions of times more potent than natural brain growth factors at promoting nerve cell connections. Research focuses on cognitive enhancement and neurodegenerative diseases.
E
F
FOXO4-DRI is a 43-amino-acid synthetic peptide that selectively eliminates senescent cells, the aged and damaged cells that accumulate in the body over time. All evidence comes from cell culture and animal studies. No human clinical trials have been conducted.
Follistatin is a naturally occurring protein that blocks myostatin, a molecule that limits muscle growth. It is being studied for muscle wasting conditions and performance enhancement. Gene therapy approaches using follistatin are also in development.
G
GHK is a naturally occurring three-amino-acid peptide found in human blood, saliva, and urine, with levels that decline with age. Separate from its copper-bound form (GHK-Cu), free GHK is being studied for its ability to influence gene activity patterns linked to tissue repair, inflammation reduction, and regeneration.
GHK-Cu is a naturally occurring peptide-copper complex found in human blood, saliva, and urine. It is being studied primarily for wound healing, skin regeneration, and anti-aging applications, and is available in topical formulations.
GHRP-2 (Growth Hormone Releasing Peptide-2) is a synthetic six-amino-acid peptide that triggers growth hormone release. It is considered more potent than GHRP-6 with less appetite stimulation.
GHRP-6 (Growth Hormone Releasing Peptide-6) is a six-amino-acid peptide that triggers growth hormone release through the ghrelin (hunger hormone) receptor. It is known for strong growth hormone release but also significant appetite stimulation.
Gonadorelin is a synthetic form of gonadotropin-releasing hormone (GnRH), a key reproductive signaling hormone. It is used diagnostically and therapeutically for fertility assessment, low hormone levels, and to maintain testicular function during testosterone replacement therapy.
H
HGH Fragment 176-191 is a stabilized piece of human growth hormone (amino acids 176-191) and the parent compound of AOD-9604. Research focuses on fat breakdown without the growth-promoting or blood sugar effects of full growth hormone.
Hexarelin is a synthetic six-amino-acid peptide and one of the most potent compounds that trigger growth hormone release. Beyond its growth hormone effects, research also shows heart-protective properties that work independently of growth hormone.
Humanin is a 24-amino-acid peptide produced by mitochondria (the energy centers of cells), encoded in mitochondrial DNA. It was discovered for its ability to protect brain cells from amyloid-beta toxicity, a hallmark of Alzheimer's disease. Research explores its roles in brain protection, metabolic regulation, and cellular stress resistance.
I
IGF-1 LR3 is a modified version of insulin-like growth factor 1 with structural changes that reduce its binding to carrier proteins. These modifications increase its potency and extend how long it stays active in the body compared to natural IGF-1.
Ipamorelin is a selective compound that triggers growth hormone release, originally developed by Novo Nordisk. It stimulates growth hormone without significantly affecting cortisol or prolactin levels. It has been studied in clinical trials for postoperative recovery.
K
KPV is a naturally occurring three-amino-acid peptide derived from alpha-MSH, a hormone involved in inflammation control. Research focuses on its strong anti-inflammatory properties, particularly in inflammatory bowel disease and skin conditions.
Kisspeptin is a brain signaling peptide that plays a critical role in reproductive hormone regulation. It works upstream of GnRH to control the hormone signaling chain between the brain and reproductive organs. It is being studied for fertility and puberty disorders.
L
LL-37 is a natural human immune defense molecule (part of the cathelicidin family) that plays a key role in the body's first line of defense against infection. Research explores its antimicrobial, wound healing, and immune-regulating properties.
Liraglutide is a medication that mimics a natural fullness hormone (GLP-1) in the body. It is FDA-approved as Victoza for type 2 diabetes and Saxenda for weight management, with an extensive record of clinical safety and effectiveness data.
M
MGF (Mechano Growth Factor) is a natural variant of the IGF-1 gene that the body produces in response to muscle being stretched or loaded during exercise. Research focuses on muscle repair, activation of muscle stem cells, and recovery from exercise-related damage.
MK-677 (Ibutamoren) is an oral (non-injectable) compound that triggers growth hormone release by mimicking the hunger hormone ghrelin. Research focuses on increasing growth hormone and IGF-1 levels, improving sleep quality, body composition, and bone density.
MOTS-c is a 16-amino-acid peptide produced by mitochondria (the energy centers of cells), encoded in mitochondrial DNA. It was the first mitochondrial peptide to enter clinical trials. Research focuses on metabolic health, exercise performance, and longevity, with natural levels declining with age.
Matrixyl is a fat-soluble signal peptide used in cosmetic skincare to boost collagen production. It works by mimicking collagen breakdown signals, prompting skin cells to produce more collagen. It is one of the most clinically validated anti-wrinkle peptides and is found primarily in topical products.
Melanotan 1 (Afamelanotide) is a synthetic version of the natural skin-darkening hormone alpha-MSH. It is FDA-approved as Scenesse, a subcutaneous implant for treating EPP, a rare genetic condition causing extreme sun sensitivity. It is also commonly used via injection or nasal spray for tanning.
Melanotan II is a synthetic version of alpha-MSH, a natural hormone involved in skin pigmentation. It activates hormone receptors involved in skin color and sexual function, and is being studied for both tanning and sexual health applications.
N
O
P
PE-22-28 is a synthetic seven-amino-acid peptide designed to block a specific potassium channel (TREK-1) in the brain. Research in animal models focuses on antidepressant-like effects and cognitive enhancement through brain growth factor support and increased brain cell adaptability.
PT-141 (Bremelanotide) is a hormone receptor activator that works directly in the brain, unlike blood flow-based medications for sexual dysfunction. It is FDA-approved as Vyleesi for treating hypoactive sexual desire disorder (HSDD) in premenopausal women.
Pinealon is a synthetic three-amino-acid peptide that may help regulate pineal gland and central nervous system function. Developed in Russia, research focuses on sleep regulation, brain cell protection, and cognitive function in aging.
R
S
SNAP-8 is an eight-amino-acid peptide used in cosmetic skincare to reduce wrinkles. It works by partially blocking nerve-to-muscle signaling in a way similar to botulinum toxin but through a different mechanism. It is used primarily in topical formulations.
SS-31 (Elamipretide) is a four-amino-acid peptide that targets and concentrates in the inner membrane of mitochondria (the energy centers of cells). It is being developed for mitochondrial diseases, heart failure, and age-related conditions.
Selank is a synthetic seven-amino-acid peptide derived from the immune protein tuftsin, developed in Russia. Research shows it has both immune-supporting and anti-anxiety properties without causing sedation or dependence.
Semaglutide is a medication that mimics a natural fullness hormone (GLP-1) in the body. It is FDA-approved as Wegovy for weight management and Ozempic for type 2 diabetes, with significant effects on appetite control and blood sugar regulation.
Semax is a synthetic peptide derived from a brain hormone fragment (ACTH 4-10), developed in Russia for brain-protective and cognitive-enhancing purposes. Research focuses on stroke recovery, cognitive function, and brain growth factor support.
Sermorelin is a synthetic 29-amino-acid growth hormone-releasing compound. It was FDA-approved for pediatric growth hormone deficiency and is widely used off-label for anti-aging and body composition improvement.
T
TB-500 is a synthetic fragment of Thymosin Beta-4, a naturally occurring protein involved in tissue repair throughout the body. Research focuses on wound healing, tissue regeneration, and reducing inflammation.
Tesamorelin is a synthetic growth hormone-releasing compound used for reducing deep abdominal fat in patients with lipodystrophy (abnormal fat distribution). It is FDA-approved and marketed as Egrifta, specifically targeting visceral fat accumulation.
Thymalin is a peptide complex originally extracted from calf thymus glands, developed in Russia. Research focuses on immune system restoration, anti-aging effects, and recovery of thymus gland function, particularly in elderly and immune-compromised individuals.
Thymosin Alpha-1 is a 28-amino-acid peptide naturally produced by the thymus gland. It has been extensively studied for immune support with over 70 clinical trials. Research covers hepatitis treatment, cancer immune therapy, and sepsis management.
Tirzepatide is a dual-action medication that activates both GIP and GLP-1 receptors, two key fullness and blood sugar hormones. It is FDA-approved as Mounjaro for type 2 diabetes and Zepbound for weight management, outperforming semaglutide in head-to-head trials.
V
Peptide Terminology
General Terms
- Reconstitution
- The process of dissolving lyophilized (freeze-dried) peptide powder in bacteriostatic water to create an injectable solution.
- Subcutaneous injection
- An injection administered into the fatty tissue layer just beneath the skin, the most common route for peptide administration.
- Lyophilized
- Freeze-dried. Most research peptides are sold in lyophilized powder form for stability during storage and shipping.
- Bacteriostatic water
- Sterile water containing 0.9% benzyl alcohol as a preservative, used to reconstitute peptides. Allows multi-use from the same vial.
- Half-life
- The time required for half of a peptide to be eliminated from the body. Determines dosing frequency.
- Secretagogue
- A substance that promotes secretion of another substance. Growth hormone secretagogues stimulate the pituitary to release GH.
- GLP-1 agonist
- A compound that activates glucagon-like peptide-1 receptors, used in metabolic and weight loss research (e.g., Semaglutide, Tirzepatide).
- Loading phase
- An initial period of higher or more frequent dosing used with some peptides to reach effective tissue concentrations faster.
- Reconstitution calculator
- A tool that calculates how much bacteriostatic water to add to a peptide vial and what syringe volume equals your target dose.
Development Stages
Each peptide profile shows a development stage indicating how far the compound has progressed through the drug development pipeline.
- Discovery
- Earliest research stage. The peptide has been identified and is being studied in laboratory or computational settings only.
- Preclinical
- Being tested in cell cultures and animal models. Has not yet been tested in humans.
- Phase 1
- First human trials. Small groups (20–80 people) to evaluate safety, dosage, and side effects.
- Phase 2
- Expanded trials (100–300 people) to assess efficacy and further evaluate safety.
- Phase 3
- Large-scale trials (1,000–3,000+ people) to confirm effectiveness, monitor side effects, and compare to existing treatments.
- FDA Review
- A New Drug Application has been submitted and is under review by the FDA for approval.
- Phase 4
- Post-marketing surveillance conducted after regulatory approval. Monitors long-term safety and effectiveness in the general population.
- Discontinued
- Development has been stopped, typically due to safety concerns, lack of efficacy, or commercial reasons.
Regulatory Approvals
Regulatory approval status indicates whether a peptide has been approved for medical use by a government health authority.
- FDA Approved
- Approved by the U.S. Food and Drug Administration for at least one medical indication.
- EMA Approved
- Approved by the European Medicines Agency for use in the European Union.
- Russia Approved
- Approved by Russia’s Ministry of Health. Several peptides (e.g., Selank, Semax) are approved in Russia but not in Western markets.
- Investigational
- Actively being studied in clinical trials but not yet approved by any major regulatory body.
- Not Approved
- No regulatory approval in any major jurisdiction. Most research peptides fall into this category.