The stomach cells are responsible for producing the protein intrinsic factor, which is needed to combine with vitamin B12
For a comprehensive summary of these trial results and Phase 3 updates, see our retatrutide clinical trials 2026 update

Reported benefits (per available research): Studied for restoring more youthful pulsatile GH and IGF-1 secretion in older adults, based on a small 1997 randomized, placebo-controlled human trial of a closely related GHRH(1-29) analog published in the Journal of Clinical Endocrinology & Metabolism May support gains in lean body mass in men specifically: that same 16-week trial found a statistically significant increase in lean body mass in men but not in women, alongside a significant increase in skin thickness (a marker of dermal collagen) in both sexes Proposed to support broader recovery and body-composition goals tied to growth-hormone-axis activity, though sermorelin-specific modern adult trial data remains thin, and much of the anti-aging and muscle-building framing used in commercial marketing outpaces the current clinical evidence base Known risks and side effects: Injection-site reactions (pain, swelling, or redness) are the most commonly reported adverse event associated with sermorelin therapy in manufacturer drug-labeling data Headache, flushing, dizziness, difficulty swallowing, hyperactivity, drowsiness, and hives have also been reported less commonly per that same labeling data

However, the amount needed can change based on your health, diet, and age
In comparison, LSS is reported to affect over 200,000 individuals in the US
Oral BPC-157 is the best choice for gut-targeted applications leaky gut, IBD, gastric repair because the peptide acts locally where it is most concentrated