Hair improvement While not the primary application, glow stack users sometimes report improved hair quality
One of the important things for vitamin B12 absorption is having enough stomach acid
Published work on intranasal peptide delivery (for insulin analogs, calcitonin, and oxytocin) demonstrates that bioavailability for this size class without enhancers is typically in the low single-digit percent range, though these data are from different peptides with different charge profiles
International Journal of Molecular Sciences (2022) MOTS-c, the Most Recent Mitochondrial Derived Peptide in Human Aging and Age-Related Diseases (Mohtashami Z, Singh MK, Salimiaghdam N, et al.) Subcutaneous Drug Injection Review (PMC) Literature review of factors influencing subcutaneous injection pharmacology Related research, protocols, and guides Explore the available research context, protocol variants or comparisons, and practical guides
Additionally, both acids and copper peptides can cause irritation