Sources & references

The literature Peptidify reads when it composes a cycle. Pharmacokinetics, dose-response, receptor mechanism, and clinical safety — grouped by mechanism class. This is not exhaustive: the model has access to a broader corpus, but these are the foundational and most-cited works that anchor each compound class.

Method

Peptidify's prompt is grounded in published peer-reviewed research, not forum protocols. For each compound we track: (1) measured pharmacokinetic profile (Cmax, Tmax, half-life, AUC), (2) primary receptor target and downstream pathway, (3) dose-response curve from human or primate trials where available, (4) reported adverse events and bloodwork shifts, (5) interaction risk with co-administered compounds.

Where human data is sparse, we fall back to primate or rodent literature and label the inference accordingly in the output. Where no published data exists for a specific compound, the agent declines to dose it and says so.

scope Research peptides only. Compounds with regulated medical indications (insulin, AAS, controlled substances) are out of scope and the agent will refuse to plan around them.

GH axis

GHRH analogs (cjc-1295, tesamorelin) and growth-hormone secretagogues (ipamorelin, hexarelin, MK-677). Two receptor families: GHRH-R and GHS-R1a. Synergy comes from orthogonal stimulation; competition from stacking two of the same family.

CJC-1295 GHRH-R agonist

  1. Teichman SL, Neale A, Lawrence B, Gagnon C, Castaigne JP, Frohman LA. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults. J Clin Endocrinol Metab. 2006;91(3):799-805.
  2. Ionescu M, Frohman LA. Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog. J Clin Endocrinol Metab. 2006;91(12):4792-7.
  3. Sackmann-Sala L, Ding J, Frohman LA, Kopchick JJ. Activation of the GH/IGF-1 axis by CJC-1295, a long-acting GHRH analog, results in serum protein profile changes in normal adult subjects. Growth Horm IGF Res. 2009;19(6):471-7.

Ipamorelin GHS-R1a agonist

  1. Raun K, Hansen BS, Johansen NL, Thøgersen H, Madsen K, Ankersen M, Andersen PH. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. 1998;139(5):552-61.
  2. Beck DE, Sweeney WB, McCarter MD; Ipamorelin 201 Study Group. Prospective, randomized, controlled, proof-of-concept study of the ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients. Int J Colorectal Dis. 2014;29(12):1527-34.

Tesamorelin GHRH-R agonist

  1. Falutz J, Allas S, Blot K, Potvin D, Kotler D, Somero M, Berger D, Brown S, Richmond G, Fessel J, Turner R, Grinspoon S. Metabolic effects of a growth hormone-releasing factor in patients with HIV. N Engl J Med. 2007;357(23):2359-70.
  2. Stanley TL, Feldpausch MN, Oh J, Branch KL, Lee H, Torriani M, Grinspoon SK. Effect of tesamorelin on visceral fat and liver fat in HIV-infected patients with abdominal fat accumulation: a randomized clinical trial. JAMA. 2014;312(4):380-9.

MK-677 / Ibutamoren GHS-R1a agonist · oral

  1. Murphy MG, Plunkett LM, Gertz BJ, He W, Wittreich J, Polvino WM, Clemmons DR. MK-677, an orally active growth hormone secretagogue, reverses diet-induced catabolism. J Clin Endocrinol Metab. 1998;83(2):320-5.
  2. Nass R, Pezzoli SS, Oliveri MC, Patrie JT, Harrell FE, Clasey JL, Heymsfield SB, Bach MA, Vance ML, Thorner MO. Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults: a randomized trial. Ann Intern Med. 2008;149(9):601-11.

Regenerative

BPC-157 (pentadecapeptide derived from gastric juice) and Thymosin β4 (TB-500 is a synthetic analog). Distinct pathways: BPC-157 acts on VEGF / nitric-oxide signaling, Tβ4 binds G-actin and drives cell migration. Stack-friendly because mechanisms don't overlap.

BPC-157 VEGF / eNOS pathway

  1. Sikiric P, Seiwerth S, Rucman R, Turkovic B, Rokotov DS, Brcic L, Sever M, Klicek R, Radic B, Drmic D, et al. Stable gastric pentadecapeptide BPC 157: novel therapy in gastrointestinal tract. Curr Pharm Des. 2011;17(16):1612-32.
  2. Sikiric P, Seiwerth S, Rucman R, Drmic D, Stupnisek M, Kokot A, Sever M, Zoricic I, Zoricic Z, Batelja L, et al. Brain-gut Axis and Pentadecapeptide BPC 157: Theoretical and Practical Implications. Curr Neuropharmacol. 2016;14(8):857-865.
  3. Chang CH, Tsai WC, Lin MS, Hsu YH, Pang JH. The promoting effect of pentadecapeptide BPC 157 on tendon healing involves tendon outgrowth, cell survival, and cell migration. J Appl Physiol. 2011;110(3):774-80.

Thymosin β4 / TB-500 actin-binding

  1. Goldstein AL, Hannappel E, Sosne G, Kleinman HK. Thymosin β4: a multi-functional regenerative peptide. Indications and possible pharmacological mechanisms. Expert Opin Biol Ther. 2012;12(1):37-51.
  2. Crockford D, Turjman N, Allan C, Angel J. Thymosin beta4: structure, function, and biological properties supporting current and future clinical applications. Ann N Y Acad Sci. 2010;1194:179-89.
  3. Bock-Marquette I, Saxena A, White MD, Dimaio JM, Srivastava D. Thymosin β4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair. Nature. 2004;432(7016):466-72.

Melanocortin class

Melanotan-II and PT-141 (bremelanotide) act on MC1R, MC3R, MC4R, MC5R with overlapping affinity. Co-administration is receptor-redundant, not synergistic. Cardiovascular and pigmentation timelines need separate monitoring.

Melanotan-II MC1/3/4/5R agonist

  1. Dorr RT, Lines R, Levine N, Brooks C, Xiang L, Hruby VJ, Hadley ME. Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study. Life Sci. 1996;58(20):1777-84.
  2. Dorr RT, Ertl G, Levine N, Brooks C, Bangert JL, Powell MB, Humphrey S, Alberts DS. Effects of a superpotent melanotropic peptide in combination with solar UV radiation on tanning of the skin in human volunteers. Arch Dermatol. 2004;140(7):827-35.

PT-141 / Bremelanotide MC4R agonist · libido

  1. Diamond LE, Earle DC, Heiman JR, Rosen RC, Perelman MA, Harning R. An effect on the subjective sexual response in premenopausal women with sexual arousal disorder by bremelanotide (PT-141), a melanocortin receptor agonist. J Sex Med. 2006;3(4):628-638.
  2. Kingsberg SA, Clayton AH, Portman D, Williams LA, Krop J, Jordan R, Lucas J, Simon JA. Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials. Obstet Gynecol. 2019;134(5):899-908.

GLP-1 / metabolic

Semaglutide (GLP-1 receptor agonist) and tirzepatide (dual GLP-1 / GIP). Long half-life, once-weekly dosing, well-characterized cardiovascular and weight-loss outcomes from large RCTs.

Semaglutide GLP-1R agonist

  1. Marso SP, Bain SC, Consoli A, Eliaschewitz FG, Jódar E, Leiter LA, Lingvay I, Rosenstock J, Seufert J, Warren ML, Woo V, Hansen O, Holst AG, Pettersson J, Vilsbøll T; SUSTAIN-6 Investigators. Semaglutide and Cardiovascular Outcomes in Patients with Type 2 Diabetes. N Engl J Med. 2016;375(19):1834-1844.
  2. Wilding JPH, Batterham RL, Calanna S, Davies M, Van Gaal LF, Lingvay I, McGowan BM, Rosenstock J, Tran MTD, Wadden TA, Wharton S, Yokote K, Zeuthen N, Kushner RF; STEP 1 Study Group. Once-Weekly Semaglutide in Adults with Overweight or Obesity. N Engl J Med. 2021;384(11):989-1002.

Tirzepatide GLP-1 / GIP agonist

  1. Frías JP, Davies MJ, Rosenstock J, Pérez Manghi FC, Fernández Landó L, Bergman BK, Liu B, Cui X, Brown K; SURPASS-2 Investigators. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes. N Engl J Med. 2021;385(6):503-515.
  2. Jastreboff AM, Aronne LJ, Ahmad NN, Wharton S, Connery L, Alves B, Kiyosue A, Zhang S, Liu B, Bunck MC, Stefanski A; SURMOUNT-1 Investigators. Tirzepatide Once Weekly for the Treatment of Obesity. N Engl J Med. 2022;387(3):205-216.

Background pharmacology

General principles the agent applies across compound classes: GH pulsatility, GPCR desensitization kinetics, receptor-binding affinity, and dose-response shape.

GH pulsatility & circadian release

  1. Hartman ML, Faria AC, Vance ML, Johnson ML, Thorner MO, Veldhuis JD. Temporal structure of in vivo growth hormone secretory events in humans. Am J Physiol. 1991;260(1 Pt 1):E101-10.
  2. Veldhuis JD, Roemmich JN, Richmond EJ, Bowers CY. Somatotropic and gonadotropic axes linkages in infancy, childhood, and the puberty-adult transition. Endocr Rev. 2006;27(2):101-40.

GHS-R1a desensitization & β-arrestin recruitment

  1. Camiña JP, Carreira MC, El Messari S, Llorens-Cortes C, Smith RG, Casanueva FF. Desensitization and endocytosis mechanisms of ghrelin-activated growth hormone secretagogue receptor 1a. Endocrinology. 2004;145(2):930-40.
  2. Holst B, Cygankiewicz A, Jensen TH, Ankersen M, Schwartz TW. High constitutive signaling of the ghrelin receptor — identification of a potent inverse agonist. Mol Endocrinol. 2003;17(11):2201-10.

Bloodwork interpretation

  1. Brabant G, von zur Mühlen A, Wüster C, Ranke MB, Kratzsch J, Kiess W, Ketelslegers JM, Wilhelmsen L, Hulthén L, Saller B, Mattsson A, Wilde J, Schemer R, Kann P; German KIMS Board. Serum insulin-like growth factor I reference values for an automated chemiluminescence immunoassay system: results from a multicenter study. Horm Res. 2003;60(2):53-60.
  2. Melmed S, Casanueva FF, Hoffman AR, Kleinberg DL, Montori VM, Schlechte JA, Wass JA; Endocrine Society. Diagnosis and treatment of hyperprolactinemia: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2011;96(2):273-88.

Note on PK figures

Pharmacokinetic curves shown on the site (and in social posts) are schematic approximations drawn from the studies above. Real Cmax values vary with route of administration, injection site, body composition, and assay sensitivity. We use the published mean values; individual response distributions are wider than any single curve can show.

half-life ranges used by the agent cjc-1295 no-DAC: ~30 min · cjc-1295 + DAC: 6-8 days · ipamorelin: ~2 h · tesamorelin: ~26 min (parent compound) · MK-677: ~6 h · BPC-157: 4-6 h (oral); injectable PK poorly characterized in humans · TB-500: 2-3 h · melanotan-II: ~30 min · PT-141: ~2.7 h · semaglutide: ~165 h · tirzepatide: ~120 h.
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