Success depends on: Molecular size: Smaller peptides ( 3000 Da): TB-500 (4963 Da) - too large Growth hormone (22,000 Da) - way too large IGF-1 (7649 Da) - too large These require injection Most healing peptides: BPC-157 : Questionable nasal (injection or oral better) TB-500: Definitely injection only Most tissue repair peptides designed for injection Growth hormone secretagogues: Ipamorelin : Injection only CJC-1295 : Injection only GH peptides not designed for nasal Bioavailability too low nasally Weight loss peptides: Semaglutide : Injection only (or oral tablet form exists) Tirzepatide : Injection only These require subcutaneous delivery Rule of thumb: If the peptide is commonly injected by everyone probably needs injection If nasal spray versions are popular nasal likely works When in doubt injection more reliable How to properly use nasal spray peptides Technique makes or breaks results

Cycling protocols vary between practitioners, with some recommending continuous use and others suggesting 4-6 week cycles with 1-2 week breaks
Copper tripeptide (GHK-Cu), a naturally occurring tripeptide, is first isolated from human plasma, but can be found in saliva and urine
Kidney function biomarkers including creatinine clearance and urea levels showed normalization toward younger reference values, indicating restoration of tissue homeostasis
By stimulating the body's production of growth hormone and other beneficial compounds, peptide therapy could help individuals maintain their health and vitality as they age
doi:10.3389/fncel.2015.00003