Some common areas of injury are the right hand, left hand, forearm, cheek, and temporomandibular area
However, not all evidence showed clinical efficacy, which could be related to the different doses, formulation issues, or duration of studies
Inhibits effect and mechanism of catalpol on the human neuroblastoma cell injury induced by rotenone

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

For example, high proteolytic sensitivity of casein was reported by McMeekin in 1952 (McMeekin, 1952)