Injury Healing

Collagen peptides are hydrolyzed collagen fragments sold as an oral supplement under names such as Peptan. Ingested peptides are absorbed and may act as signaling molecules that stimulate fibroblast activity and matrix production. Randomized trials and meta-analyses report improvements in skin hydration and elasticity, although study quality and industry funding vary considerably.

How it works: Hydrolyzed collagen fragments are absorbed and may signal fibroblasts to increase collagen and extracellular matrix synthesis.

Skin hydration; skin elasticity; nail and hair support; joint and bone research

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

SYN-COLL is the trade name for palmitoyl tripeptide-5, a synthetic lipopeptide built from a lysine-valine-lysine sequence attached to a palmitic acid chain. It is used in topical cosmetic products marketed to support the appearance of firmer, smoother skin. It is described as mimicking a region of thrombospondin-1 that can activate a collagen-promoting signal. Published support is largely laboratory and manufacturer based. It is regulated as a cosmetic ingredient.

How it works: It is designed to mimic thrombospondin-1 and activate latent TGF-beta, a signal associated with collagen production by fibroblasts.

Skin firmness; fine line appearance; collagen support; cosmetic anti-aging

Somatropin is recombinant human growth hormone and is FDA approved. Approved uses include growth hormone deficiency in children and adults and short stature associated with conditions such as Turner syndrome, Prader-Willi syndrome, chronic kidney disease, and being born small for gestational age without catch-up growth. It is given by subcutaneous injection and supplements the body's own growth hormone.

How it works: It binds the growth hormone receptor to drive growth and metabolism directly and by inducing insulin-like growth factor 1.

Growth hormone deficiency; pediatric short stature; Turner syndrome; Prader-Willi syndrome

This entry describes glycyl-L-histidyl-L-lysine copper as a topical serum presentation. It is the same molecule as the existing GHK-Cu row and differs only by presentation. GHK-Cu is a copper-binding tripeptide studied for effects on collagen synthesis, matrix remodeling, and wound repair, used mainly as a topical cosmetic ingredient.

How it works: It carries copper into tissue and acts as a signaling molecule that modulates genes linked to matrix remodeling and repair.

Skin anti-aging; collagen support; wound healing research; hair research

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

Semax is a synthetic heptapeptide analog of a fragment of the hormone ACTH, modified with a Pro-Gly-Pro tail to resist rapid enzymatic breakdown. In laboratory and animal studies it raises brain levels of BDNF and NGF and influences monoamine signaling, and it is mainly studied for stroke recovery, cognition, and neuroprotection. It is registered and used in Russia for ischemic conditions but is not FDA approved.

How it works: It acts as a stabilised ACTH(4-7) fragment analog that raises brain BDNF and NGF and modulates monoamine signaling.

Ischemic stroke; cognitive function; neuroprotection; attention and focus

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

Teriparatide is a recombinant fragment of human parathyroid hormone, given by subcutaneous injection. It is FDA approved to treat osteoporosis in people at high risk of fracture, where intermittent dosing stimulates new bone formation. It formerly carried a boxed warning for osteosarcoma based on rat studies, which the FDA removed in 2020 after human data did not show an increased risk.

How it works: Intermittent activation of parathyroid hormone receptors on bone cells stimulates new bone formation.

Osteoporosis treatment; fracture risk reduction; bone formation

Abaloparatide is a synthetic analog of parathyroid hormone-related protein that acts as a selective PTH1 receptor agonist. It is FDA approved to treat osteoporosis in postmenopausal women at high fracture risk and to increase bone density in men with osteoporosis at high fracture risk. It works as an anabolic bone-forming agent given by daily subcutaneous injection.

How it works: It is a selective PTH1 receptor agonist that stimulates osteoblast-mediated bone formation with relatively limited bone resorption.

Postmenopausal osteoporosis; male osteoporosis; fracture risk reduction; bone density

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

Ziconotide is a synthetic peptide analog of a cone snail venom toxin, marketed as Prialt. It is FDA approved for the management of severe chronic pain in adults who require delivery into the spinal fluid and who are intolerant of or unresponsive to other treatments, including intrathecal morphine. It blocks N-type calcium channels on spinal neurons to reduce pain transmission.

How it works: It blocks N-type voltage-gated calcium channels on spinal pain neurons, reducing release of pain-signaling neurotransmitters.

Severe chronic pain; intrathecal analgesia; refractory pain

Botulinum toxin type A is a purified neurotoxin protein produced by Clostridium botulinum and marketed as Botox. It is FDA approved for a broad range of therapeutic uses, including chronic migraine, cervical dystonia, spasticity, overactive bladder, severe underarm sweating, and blepharospasm. It acts locally at the neuromuscular junction to inhibit acetylcholine release.

How it works: It cleaves SNARE proteins to inhibit acetylcholine release at the neuromuscular junction, producing local chemodenervation.

Chronic migraine; cervical dystonia; spasticity; overactive bladder; hyperhidrosis

B7-33 is a single-chain analog of the hormone relaxin, simplified from the natural two-chain structure into one linear peptide that still activates the relaxin receptor RXFP1. It is described as a functionally selective agonist that favors pathways reducing tissue scarring. In rodent models of heart and lung disease it reduced organ fibrosis, supporting interest as an anti-fibrotic agent. It has only been studied in preclinical research.

How it works: It is a single-chain relaxin analog that selectively activates the RXFP1 receptor, favoring signaling that reduces fibrosis.

Anti-fibrotic research; cardiac remodeling; RXFP1 activation; organ fibrosis research

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

ACE-031 is a fusion protein linking the extracellular domain of the activin receptor type IIB to an antibody Fc region, forming a soluble decoy receptor. By trapping myostatin and related ligands before they reach signaling receptors, it aimed to reduce natural limits on muscle growth. It was tested in boys with Duchenne muscular dystrophy, but development was discontinued after safety findings.

How it works: It acts as a soluble decoy receptor that captures myostatin and related ligands before they can activate the receptors that restrain muscle growth.

Myostatin inhibition; muscle wasting research; muscular dystrophy studies; muscle preservation

Brimapitide is a cell-penetrating peptide that inhibits c-Jun N-terminal kinase, a stress-activated signaling pathway implicated in cochlear hair cell damage. It was investigated as a single injection into the middle ear for acute inner ear hearing loss and received FDA Fast Track and orphan-drug designations. Its phase 3 program did not meet the primary hearing-recovery endpoint, and it is not approved.

How it works: It is a cell-penetrating peptide that blocks c-Jun N-terminal kinase signaling to reduce stress-induced death of cochlear hair cells.

Sudden sensorineural hearing loss; acoustic trauma; otoprotection research

Dermorphin is a naturally occurring heptapeptide first isolated from the skin of South American Phyllomedusa frogs. It is a highly potent and highly selective mu-opioid receptor agonist reported to be many times more potent than morphine. It has served as a research tool in opioid pharmacology and analgesia and is notorious for illicit use as a performance enhancer in horse racing. As a strong opioid agonist it carries serious risks.

How it works: It acts as a high-affinity, highly selective mu-opioid receptor agonist, activating opioid signaling to produce potent analgesia.

Opioid research; analgesia research; receptor pharmacology

Risuteganib is a synthetic oligopeptide given by injection into the eye. It inhibits several integrins involved in angiogenesis, inflammation, and vascular permeability and is proposed to affect retinal oxidative-stress pathways. It has been evaluated in phase 2 trials for non-exudative age-related macular degeneration and diabetic macular edema, and it remains investigational and unapproved.

How it works: It is an integrin inhibitor that reduces angiogenesis, vascular permeability, and oxidative stress in the retina.

Dry age-related macular degeneration; diabetic macular edema; retinal integrin research

Efocipegtrutide is an investigational long-acting triple agonist of the GLP-1, GIP, and glucagon receptors, developed by Hanmi Pharmaceutical using a peptide-Fc conjugation technology. It has no regulatory approval. It has been studied mainly in metabolic dysfunction-associated steatohepatitis and obesity, with phase 2 trials evaluating liver fat, body weight, and safety.

How it works: It activates GLP-1, GIP, and glucagon receptors together to reduce appetite, lower liver fat, and increase energy expenditure.

Metabolic liver disease; NASH; obesity; weight loss

Pentadeca Arginate is an arginate-salt peptide structurally related to BPC-157, a synthetic pentadecapeptide derived from a gastric protein sequence. It is an emerging tissue-repair research compound promoted for improved stability relative to BPC-157, but peer-reviewed studies on PDA itself are essentially absent. Reported repair-related activity derives largely from BPC-157 literature rather than from PDA-specific research.

How it works: It is proposed to support blood vessel formation and tissue repair through pathways described for BPC-157.

Tissue repair research; tendon recovery research; gastrointestinal repair research

Cartalax is a short synthetic tripeptide of alanine, glutamate, and aspartate developed within the Russian Khavinson peptide bioregulator program and assigned to cartilage and connective tissue. It is proposed to act as an epigenetic regulator that influences the expression of genes involved in cartilage and matrix maintenance, though this mechanism remains largely unverified. Published human research is minimal and confined mostly to its originating laboratory.

How it works: It is proposed to act as a peptide bioregulator that influences gene expression in cartilage and connective tissue cells.

Cartilage research; connective tissue; joint support; cellular bioregulation

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

Thymosin beta-4 is a naturally occurring 43 amino acid protein that binds and sequesters actin, influencing cell migration, tissue repair, blood vessel formation, and inflammation. Laboratory and animal studies describe roles in wound healing and tissue regeneration, and a synthetic ophthalmic formulation has been evaluated for dry eye and neurotrophic keratopathy. It is the full-length protein, distinct from the TB-500 fragment, and it is not approved.

How it works: It binds and sequesters actin to regulate the cytoskeleton, supporting cell migration, tissue repair, and blood vessel growth.

Tissue and wound repair; ophthalmic surface healing; tissue regeneration research

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

Deltorphin II is a naturally occurring heptapeptide found in the skin secretions of South American Phyllomedusa frogs. It is a potent and highly selective agonist of the delta-opioid receptor and is used mainly as a pharmacological research tool. In animal models it produces pain-reducing effects. It is not an approved therapeutic and carries opioid-type safety considerations.

How it works: It is a highly selective and potent agonist of the delta-opioid receptor, containing a D-amino acid that resists breakdown.

Delta-opioid research; antinociception research; opioid pharmacology

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.

Endomorphin-1 is an endogenous tetrapeptide that acts as a highly selective, high-affinity agonist of the mu-opioid receptor. It is found in brain regions rich in mu-opioid receptors and is studied as a potential analgesic and morphine alternative. It is rapidly broken down by peptidases, which limits drug development, and as a mu-opioid agonist it carries opioid-type safety risks.

How it works: It is an endogenous, highly selective, high-affinity mu-opioid receptor agonist that inhibits neuronal excitability.

Mu-opioid research; analgesia research; endogenous opioid studies

TB-500 is a synthetic peptide based on the actin-binding region of thymosin beta-4, a protein found naturally in most cells. In laboratory and animal studies it binds actin and supports cell migration, blood vessel formation, and tissue repair, which is why it is explored for wound healing and injury recovery. It has no human approval, though full-length thymosin beta-4 has reached human eye and heart trials.

How it works: It sequesters actin monomers to support cell migration, blood vessel growth, and tissue repair.

Wound healing; tissue repair; injury recovery; cardiac repair; anti-inflammatory research

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

BPC-157 is a synthetic peptide of fifteen amino acids derived from a protective protein found in human gastric juice. In animal models it appears to speed tissue repair by promoting new blood vessel formation and modulating inflammation and growth-factor signaling. It is studied mainly for tendon, ligament, and gastrointestinal healing. It is not approved by any regulator, and human evidence remains very limited.

How it works: It is thought to speed healing by promoting blood vessel formation and modulating inflammatory and growth-factor pathways, based mainly on animal data.

Tendon healing; ligament repair; gastrointestinal healing; wound healing; neuroprotection research

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

The KL1 domain is one of the two internal repeat domains of the Klotho protein and can exist as a secreted fragment. Research suggests KL1 carries out several of Klotho's aging-related actions independently of FGF23 signaling, including inhibition of IGF-1, Wnt, and TGF-beta pathways, and a KL1 construct has shown anti-cancer activity in the laboratory. It is a distinct experimental entity from full-length Klotho, with no approved use.

How it works: It acts largely independently of FGF23, inhibiting IGF-1, Wnt, and TGF-beta signaling pathways implicated in aging and tumor growth.

Longevity research; cancer research; cellular aging

Cebranopadol is an investigational orally active analgesic that acts as a full agonist at both the nociceptin/orphanin FQ peptide receptor and the mu-opioid receptor. It has been studied in clinical trials for acute, chronic, neuropathic, and cancer pain. It remains investigational and is not approved for human use. Because it engages mu-opioid receptors, it carries opioid-type safety risks.

How it works: It is a full agonist at the nociceptin and mu-opioid receptors, with partial activity at kappa and delta opioid receptors.

Chronic pain; acute and postoperative pain; neuropathic pain; cancer pain

Conantokin G is a small peptide isolated from the venom of the fish-hunting cone snail Conus geographus. It acts as an NR2B-selective antagonist of NMDA-type glutamate receptors. It has been examined mainly as a research tool and in early development for epilepsy, neuropathic pain, and protection against excitotoxic brain injury. It is not an approved therapeutic.

How it works: It is an NR2B-selective antagonist of NMDA-type glutamate receptors, a venom-derived peptide rich in gamma-carboxyglutamate.

NMDA receptor research; epilepsy research; neuropathic pain; neuroprotection