Educational content only — not medical advice. Many compounds below are investigational, unapproved for human use, or have limited human evidence. This is meant to explain the research landscape, not provide protocols or recommendations. One of the reasons the peptide world can feel overwhelming is that there are so many different compounds being discussed for completely different purposes. Some are being studied around tissue signaling and recovery, others around metabolism, mitochondrial function, hormones, cognition, or skin biology. Instead of looking at them as one giant list, it helps to group them by what researchers are actually interested in studying. REPAIR, RECOVERY & AGING - This category centers around tissue signaling, inflammation, mitochondrial function, and cellular aging. BPC-157 — Primarily discussed in preclinical research involving gastrointestinal tissue, wound healing, tendons, ligaments, and other forms of tissue repair. TB-500 / thymosin beta-4–related research — Studied for cellular migration, tissue regeneration, angiogenesis, and inflammatory signaling, with much of the peptide-market discussion extrapolated from thymosin beta-4 research. GHK-Cu — A naturally occurring copper-binding peptide studied extensively in skin biology, collagen production, wound repair, and hair-related applications. KPV — A small peptide fragment derived from α-MSH that has attracted research interest for anti-inflammatory activity, particularly involving intestinal and immune signaling. Epithalon — An experimental peptide associated with aging, circadian biology, and telomere-related research. Human evidence remains limited. NAD+ — Not actually a peptide, but an essential cellular coenzyme involved in energy metabolism, mitochondrial function, DNA repair, and cellular aging. Glutathione — Also not a traditional research peptide; it is a naturally occurring antioxidant involved in oxidative stress regulation, cellular defense, and detoxification pathways. Thymosin Alpha-1 — An immune-modulating peptide studied for its effects on T-cell function and other aspects of immune regulation.