Acetyl tetrapeptide-5
is used in cosmetic eye formulations to decrease puffiness, eye bags, and dark circles by reducing edema and protecting proteins such as SOD from glycation
Alanine
Ala / A · hydrophobic residue · neutral charge
AOD-9604
is studied as an anti-obesity peptide that can reduce weight gain and increase fat oxidation in obese animal models with generally neutral effects on IGF-1 and glucose metabolism in early human trials
Arginine
Arg / R · basic residue · positive charge
Argireline
is a topical cosmetic peptide reported to decrease dynamic wrinkles by partially mimicking the mechanism of botulinum toxin in a non-invasive manner
Asparagine
Asn / N · polar residue · neutral charge
Aspartic acid
Asp / D · acidic residue · negative charge
BPC-157
is investigated for accelerating healing of gastrointestinal mucosa, tendons, ligaments, bone, and nervous tissue in preclinical models, with anti-inflammatory and pro-angiogenic effects
Comparison
While Kisspeptin is a key regulator of the hypothalamic–pituitary–gonadal axis, controlling puberty and fertility; kisspeptin-10 also inhibits trophoblast invasion and tumor metastasis in experimental models339199, PT-141 is FDA-approved for treatment of hypoactive sexual desire disorder in premenopausal women and is studied for sexual dysfunction in other populations, increasing sexual desire via CNS melanocortin pathways42101.
While Kisspeptin works as a family of peptides (eg, kisspeptin-10, -13, -14, -54) derived from the KISS1 precursor that activate G-protein–coupled receptor KISS1R (GPR54), triggering GnRH release and regulating pubertal onset and reproductive axis activity339199, PT-141 is the synthetic melanocortin receptor agonist bremelanotide, an analog of α-MSH that activates central MC3R and MC4R to modulate neuronal circuits governing sexual desire and arousal3242101.
Kisspeptin
KISS1
PT-141
POMC
Both peptides fall into a similar broad context as Neuropeptides, although the details of how they are used and discussed still diverge. Both are often discussed in Reproductive health contexts, while Kisspeptin is more of a hormone peptide and PT-141 is better described as a neuropeptide. Their biological logic is quite different: Kisspeptin is a receptor agonist, whereas PT-141 is a neurotransmitter modulator and a signaling modulator. Kisspeptin has a more natural endogenous origin, while PT-141 is closer to synthetic analog background and their development context also differs, with Kisspeptin in Preclinical development while PT-141 is approved. Kisspeptin takes the form of a linear peptide, whereas PT-141 is closer to a cyclic peptide, Kisspeptin carries amidation features, while PT-141 instead reflects acetylation changes; while their sequence patterns also diverge, with Kisspeptin showing alpha-helical domain features and PT-141 showing protein-mimetic sequence features.