Small molecules. Powerful biological signals.

Some of the most recognizable peptide-based medications today target the pathways involved in appetite, satiety, glucose regulation, and energy balance. This category includes GLP-1 receptor agonists and multi-receptor agonists targeting GLP-1 and GIP, which have dramatically changed the medical approach to obesity and metabolic disease.

But medication is only one part of the equation. My approach combines appropriate medical therapy with nutrition, adequate protein, resistance training, preservation of muscle mass, gut health, and improvement of the patient’s overall metabolic environment.

Rather than administering growth hormone itself, these compounds are designed to stimulate the body’s own growth-hormone release. GHRH analogs such as sermorelin or CJC-1295 act on the growth-hormone-releasing hormone pathway, while ipamorelin acts through the ghrelin receptor.

Depending on the compound and situation, this category is discussed in relation to body composition, recovery, sleep, and GH/IGF-1 physiology. These therapies require appropriate medical evaluation and monitoring.

PT-141 approaches sexual function differently from medications that primarily influence blood flow. It acts through melanocortin receptors in the central nervous system and is FDA-approved under specific conditions for acquired, generalized hypoactive sexual desire disorder in certain premenopausal women.

Its mechanism illustrates an important principle of peptide medicine: sexual function isn’t exclusively about circulation. The brain matters too.

BPC-157 has generated enormous interest because of preclinical research involving tissue repair, angiogenesis, gastrointestinal tissues, tendons, and ligaments. But there is an important distinction between interesting laboratory research and proven human clinical therapy.

Much of the enthusiasm extends beyond the quality of available human evidence, and BPC-157 is not FDA-approved for treating disease in humans. That doesn’t make the science uninteresting. It means we need to discuss it accurately.

GHK-Cu is a naturally occurring copper-binding peptide with significant interest in skin and tissue biology. Research has examined its relationship with extracellular matrix remodeling, collagen-related pathways, wound biology, and hair and skin physiology. It’s perhaps best known today for its growing presence in cosmetic and skin-health applications.

It’s also a good example of something bigger: a small signaling molecule can potentially influence many downstream biological processes.

MOTS-c is a mitochondrial-derived peptide being investigated for its relationship with cellular metabolism, metabolic homeostasis, insulin sensitivity, exercise physiology, and healthy aging. Unlike established FDA-approved peptide medications, it remains investigational.

But its biology raises a fascinating question: can signaling molecules originating from our mitochondria influence how the rest of the body responds to metabolic stress? That’s an area worth watching.