Muscle building
Training-induced muscle hypertrophy and recovery. GH secretagogues and IGF-1 related peptides are heavily discussed in bodybuilding forums; randomised human studies with hypertrophy endpoints are the rare exception, not the rule.
Peptides on this topic
8 peptiden met onderzoek naar dit onderwerpFollistatin is an endogenous glycosylated binding protein (~35 kDa, considerably larger than typical peptides) that binds and neutralises members of the TGF-β superfamily, including activin and myostatin (GDF-8). In animal models, raising follistatin de-represses muscle growth. Clinically it has been studied mainly via AAV gene therapy (FS344) in muscular dystrophies. Follistatin is not an approved drug; human efficacy and safety data are limited and stem mostly from early gene-therapy trials and preclinical research. A 'follistatin-344' product is sold on the grey market, the identity and purity of which cannot be verified without analytics.
- DiermodelTransgenic overexpression of follistatin markedly increased skeletal muscle mass in mice — beyond the level of myostatin knockout alone
- DiermodelFollistatin-based myostatin inhibitor increased muscle mass and ameliorated dystrophic pathology in mdx mice (animal model of muscular dystrophy)
Synthetic hexapeptide of the GH secretagogue family. Approved in Japan as GHRP Kaken as a diagnostic test for GH deficiency. Not available as a medicine outside Japan.
- Humane studieRobust acute GH rise after single intravenous or subcutaneous administration documented in healthy volunteers and in GH-deficient patients
Synthetic hexapeptide that founded the class of growth-hormone-releasing peptides (GHRPs). Cyril Bowers identified GHRP-6 in the late 1970s as the first orally and parenterally active GH secretagogue with no structural similarity to GHRH. Never approved as a medicine; downstream analogs (GHRP-2, hexarelin, ipamorelin) were pursued clinically.
- Humane studieRobust acute GH rise after single intravenous or subcutaneous administration documented in healthy volunteers and in GH-deficient patients
Synthetic hexapeptide of the growth-hormone secretagogue (GHRP) family. In the 1990s investigated as an acromegaly diagnostic and for GH deficiency. Not an approved medicine.
- Humane studieAcute rise of serum GH and IGF-1 after single dose observed in healthy volunteers and GH-deficient patients
Synthetic analogue of insulin-like growth factor 1 (IGF-1) carrying an arginine substitution at position 3 and a 13-amino-acid N-terminal extension. These modifications lower binding to IGF-binding proteins and extend its duration of action relative to native IGF-1. LR3 IGF-1 is primarily an established cell-culture reagent (serum-free media, bioprocessing); it is NOT an approved human medicine. Use in the bodybuilding grey market is described; as an IGF-1 analogue, LR3 IGF-1 falls under the WADA anti-doping prohibition.
- TheoretischControlled human trials on the efficacy or safety of the LR3 analogue (muscle building, regeneration, clinical endpoints) are virtually absent
Synthetic pentapeptide and selective growth-hormone secretagogue. Developed at Novo Nordisk in the 1990s as a pentapeptide GHRP successor; clinical development was discontinued after phase 2 (post-operative ileus).
- Humane studieSelective GH stimulation without significant rise in ACTH/cortisol/prolactin documented in phase-1 studies in healthy volunteers
Synthetic peptide corresponding to the C-terminal E-domain of the IGF-1 splice variant IGF-1Ec. Described in preclinical studies as a 'mechano-induced' skeletal muscle repair factor. No marketing approval; clinical use largely confined to the black market.
- In vitroActivation of muscle satellite cells and enhanced myoblast proliferation documented in cell-culture studies
- DiermodelImproved muscle regeneration after injury observed in mouse models with local intramuscular injection
MOTS-c is a 16-amino-acid mitochondrial-encoded peptide (mitochondrial-derived peptide, MDP) whose open reading frame lies within the 12S rRNA region of mitochondrial DNA. In basic research (including the laboratories of Changhan Lee and Pinchas Cohen) it is described as a regulator of metabolic homeostasis and an activator of the AMPK pathway, and is sometimes discussed as an 'exercise mimetic'. The evidence comes almost entirely from cell and animal models; controlled human trials of MOTS-c as a therapeutic are lacking. It is not approved as a medicine anywhere and is traded on the grey market as a research chemical.
- Humane studieEndogenous blood and skeletal-muscle MOTS-c levels change in humans in association with physical activity