The definitive guide to peptides

BPC-157 is a synthetic pentadecapeptide derived from human gastric juice. It has demonstrated potent healing properties across tendons, ligaments, muscles, the gut lining, and the nervous system in preclinical research. It is one of the most widely studied peptides for tissue repair and injury recovery.

Semaglutide is a GLP-1 receptor agonist approved by the FDA for type 2 diabetes (Ozempic, Rybelsus) and chronic weight management (Wegovy). It is the most widely prescribed GLP-1 medication globally and demonstrated a landmark 20% reduction in major cardiovascular events in the SELECT trial, establishing it as the first anti-obesity drug with proven cardiovascular benefit.

Tirzepatide is a first-in-class dual GIP/GLP-1 receptor agonist approved by the FDA for type 2 diabetes (as Mounjaro) and chronic weight management (as Zepbound). In landmark clinical trials, it demonstrated weight loss of up to 20-25% of body weight, making it one of the most effective anti-obesity medications ever developed.

GHK-Cu is a naturally occurring copper-binding tripeptide found in human plasma, saliva, and urine. It declines significantly with age, dropping from ~200 ng/mL at age 20 to ~80 ng/mL by age 60. Research shows it activates stem cells, promotes collagen synthesis, reduces inflammation, and may reset gene expression toward a healthier, more youthful pattern.

TB-500 is a synthetic version of Thymosin Beta-4, a 43-amino acid peptide naturally present in virtually all human cells. It plays a critical role in tissue repair, cell migration, and blood vessel formation. TB-500 is widely used in healing protocols for its ability to reduce inflammation and promote repair of injured muscles, tendons, and ligaments.

Ipamorelin is a highly selective growth hormone secretagogue peptide (GHRP) that stimulates GH release through the ghrelin/GHS receptor. It is distinguished from other GHRPs by its remarkable selectivity — it triggers robust GH release with minimal impact on cortisol, prolactin, or appetite. This clean side-effect profile has made it one of the most popular peptides in anti-aging and performance optimization protocols.

Retatrutide is an investigational triple-hormone receptor agonist developed by Eli Lilly that simultaneously activates GIP, GLP-1, and glucagon receptors. In phase 2 trials, it produced unprecedented weight loss of up to 24.2% of body weight at 48 weeks, surpassing all other anti-obesity medications in development. It is currently in phase 3 clinical trials with search interest growing over 500%.

PT-141 (bremelanotide) is a melanocortin receptor agonist FDA-approved under the brand name Vyleesi for hypoactive sexual desire disorder (HSDD) in premenopausal women. Unlike PDE5 inhibitors such as Viagra, PT-141 acts centrally in the brain to enhance sexual desire rather than working peripherally on blood flow. It is the first and only FDA-approved on-demand treatment for low sexual desire.