Injectable and Topical Peptides in Aesthetic Medicine Mechanisms, Clinical Applications, and Future Potential 

From collagen stimulation to fat metabolism and neuroregeneration, peptides are redefining aesthetic practice. Raheleh Sarbaziha, MD, and David J. Goldberg, MD, explore their mechanisms, delivery routes, and clinical synergy

The emergence of peptides in aesthetic and regenerative medicine has marked a paradigm shift in how clinicians address ageing, skin health, and systemic vitality. These bioactive molecules—administered via injection, topical application, intravenous infusion, or nasal delivery — offer targeted solutions for a wide spectrum of cosmetic and functional concerns, including skin laxity, inflammation, fat accumulation, hormonal imbalance, and cognitive decline^{3,4,10–13, 16–18}.

However, it is crucial to recognise that not all peptides are created equal, and appropriate protocols, delivery methods, and clinical insight are essential to ensure optimal outcomes and patient safety. While some peptides are FDA-approved for specific indications, others are used off-label within a well-informed, integrative framework. Patient variability in metabolism, hormone levels, and tissue responsiveness means that personalisation is key when designing peptide-based protocols.

This review highlights the clinical applications, mechanisms of action, and synergistic opportunities of various peptides—both injectable and topical—based on emerging studies and practitioner experience. Drawing on case examples and current data, we aim to illustrate how peptides can safely enhance results across diverse skin types and demographics, with a particular emphasis on integrative, cellular-level rejuvenation.

What are peptides?

Peptides are defined as short chains of amino acids that act as biological messengers. Depending on their sequence and structure, they influence diverse physiological functions such as collagen production, lipolysis, neurochemical balance, and immune modulation^1–3,5,6,19. Available in injectable, topical, intravenous, intranasal, and oral forms, peptides have demonstrated safety and efficacy in multiple regenerative and aesthetic protocols.

Injectable peptides in aesthetic medicine  

Injectable peptides such as BPC-157, GHK-Cu, TB-500, CJC-1295, Ipamorelin, and Tesamorelin target tissue repair, skin rejuvenation, fat loss, and cognitive support. For example, BPC-157 supports angiogenesis and wound healing^1,2, while GHK-Cu promotes fibroblast activation, collagen synthesis, and hair regrowth³. CJC-1295 and Ipamorelin stimulate endogenous growth hormone, improving skin tone and fat metabolism^10,20. Tesamorelin, FDA-cleared for lipodystrophy, reduces visceral fat and supports cognitive function¹¹. Additionally, GLP-1 receptor agonists such as semaglutide and tirzepatide promote weight loss, with synergistic benefits when combined with peptides that preserve muscle mass^12–14,18. Other advanced agents include FOXO4-DRI, a senolytic that targets ageing cells^8,9,21, and IGF-1 LR3 for muscle and skin health^22,23.

Topical peptides

Topical peptides such as GHK-Cu, Argireline (Lubrizol Wickliffe, Ohio, USA), Matrixyl (Sederma, France), and Snap-8 (Lubrizol Wickliffe, Ohio, USA) offer anti-ageing benefits when applied post-procedure or on their own. They reduce dynamic rhytides, promote dermal remodelling, and enhance hydration^3,5–7.

Exosomes can also carry peptides and amino acids and can further boost outcomes by delivering growth factors and RNA fragments to stimulate regeneration. In combination with peptides and energy-based modalities, they optimise recovery and collagen renewal²⁴.

Discussion

Peptides offer a promising therapeutic strategy in aesthetics but must be used judiciously. While agents like PT-141 are FDA-cleared for specific indications²⁵, others, such as Melanotan-II, are not and pose risks such as hyperpigmentation²⁵. However, regardless of regulatory oversight, the black market for peptide use is thriving and unlikely to diminish. Patients are obtaining significant results with peptides, often without medical supervision, due to their perceived safety and efficacy. As clinicians, our role is not only to understand these agents but also to guide patients toward safer, evidence-based choices. By staying educated, we can help patients navigate the growing availability of peptides and steer them away from potentially harmful or poorly formulated products. Moreover, because peptides are simply short chains of amino acids—foundational building blocks of proteins—they may be considered closer to nutraceuticals or functional supplements rather than traditional pharmaceuticals, depending on structure, route of use, and regulation^3,24. As we move forward, the integration of peptide therapies with hormonal support, appropriate diagnostics, and personalised protocols will be essential to optimise safety and patient outcomes.

Conclusion

Peptides are powerful tools that bridge the gap between traditional aesthetic procedures and regenerative medicine. Their clinical integration—particularly when combined with technologies such as exosomes, microneedling, and energy-based devices—offers a patient-centred, biological approach to skin health, body composition, and overall vitality. As the field evolves, so too must our understanding and responsible use of these therapies.

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