Peptides for Skin & Hair – Thymosin Beta 4

Peptides for Skin & Hair – Thymosin Beta 4

The quality of our skin and hair are not only indicators of a youthful look, but also of health. Not only that, our skin is one of the main ways that our immune system protects us from harmful pathogens, so having healthy skin is more than just about looking good.  A dull or sallow complexion and dry, sparse hair can be effects of stress, poor sleep, under nourishment, or other conditions that are harmful to our health. Hair and skin care are both major pillars of the beauty industry, with the US alone spending about $13 billion per year on hair care (Statista Hair Care, n.d.) and $21 billion per year on skin care (Statista Skin Care, n.d.). While topical treatments can help, it is more effective to start from within in order to influence the cellular health of our epidermis and follicles. Both our skin and hair are largely made up of protein, and peptides are the building blocks of protein and act as modulators for different receptors and molecules in the body. Our hair is “a filamentous biomaterial consisting mainly of proteins in particular keratin” (Yang, Zhang & Rheinstädter, 2014) and our skin, the largest organ of our body, is made up of “water, protein, fats and minerals” (Cleveland Clinic, 2021). Eating a healthy diet, drinking enough water, and taking certain supplements such as collagen will all assist with skin and hair health. However for people who wish to do even more, peptides such as Thymosin Beta 4 are great options.

Thymosin Beta 4, also known as TB4 or Tβ4, gets its name from the fact that it is related to thymosin, a hormone made by our thymus. While they may sound similar, the thymus is different from the thyroid gland in our throat (which helps control our metabolism, growth) or the hypothalamus in our brain (which helps control our temperature and heart rate). The thymus is an organ located in our chest between our lungs which “ serves as the body’s defense mechanism providing surveillance and protection against diverse pathogens, tumors, antigens and mediators of tissue damage” (Thapa & Farber, 2019). Thymosin Beta 4 is a highly conserved, naturally occurring, water-soluble regenerative peptide that is found in all tissues and in all cell types, except red blood cells (Goldstein and Kleinman, 2015).  TB4 is made up of 43 amino acids, segments of which “regulate the anti-inflammatory and antifibrotic effects…inhibit apoptosis and reduce the toxicity induced damage caused to cells …[and] triggers angiogenesis and growth of hair follicles” (Xing et al., 2021). Many of the published clinical trials are on its effectiveness in wound healing, and it also acts as an anti-inflammatory, analgesic, improves T cells, protects and repairs our cells and neurons, helps develop new blood vessels, and more.

Per Seeds (2020) Thymosin Beta 4 has three primary mechanisms of action:

  1. Upregulates cell-building proteins such as actin, a protein that along with myosin in muscle cells forms the contractile filament [i.e. muscle fibers].
  2. Upregulation of actin allows TB4 to promote healing, cell growth, cell migration, and cell proliferation [i.e. cell division].
  3. Due to its low molecular weight, TB4 is able to “hone” and “travel” to the site of injury to help with repair.

Thymosin Beta 4 is endogenous and occurs in most of our cells naturally. Taken intravenously, it is well tolerated and with only the possible side effect of tiredness. The first study that showed TB4 helped with tissue repair was in 1999 (Thymosin beta 4 accelerates wound healing, by Malinda et al. in the Journal of Investigative Dermatology), and the most current research focuses on how it can help “the kidney, liver, heart, brain, intestine, and other organs, as well as hair loss, skin trauma, cornea repairing, and other conditions” (Ying et al., 2023). Although it is primarily used in medical settings for tissue and muscle repair, it is cosmetically used for skin and hair health.


Cleveland Clinic.  (2021, October 13). Skin: Layers, structure and function.,%2C%20protein%2C%20fats%20and%20minerals.

Goldstein, A. L., & Kleinman, H. K. (2015). Advances in the basic and clinical applications of thymosin β4. Expert opinion on biological therapy, 15 Suppl 1, S139–S145.

Kleinman, H. K., & Sosne, G. (2016). Thymosin Β4 promotes dermal healing. Vitamins and Hormones, 251–275. 

Statista Hair Care (n.d.). Retrieved June 15, 2023, from

Statista Skin Care (n.d.). Retrieved June 15, 2023, from

Thapa, P., & Farber, D. L. (2019). The Role of the Thymus in the Immune Response. Thoracic surgery clinics, 29(2), 123–131.

Seeds, W. A. (2020). The peptide protocols: A handbook for practitioners. Spire Institute.

Xing, Y., Ye, Y., Zuo, H., & Li, Y. (2021). Progress on the Function and Application of Thymosin β4. Frontiers in endocrinology, 12, 767785.

Yang, F. C., Zhang, Y., & Rheinstädter, M. C. (2014). The structure of people’s hair. PeerJ, 2, e619.

Ying, Y., Lin, C., Tao, N., Hoffman, R. D., Shi, D., Chen, Z., & Gao, J. (2023). Thymosin β4 and Actin: Binding Modes, Biological Functions and Clinical Applications. Current protein & peptide science, 24(1), 78–88.

About the author: Mary Genevieve Carty, MS, MHEd holds Masters degrees in Complementary and Integrative Health as well as Higher Education and is currently a doctoral student in Health Science at George Washington University’s College of Medicine and Health Science.  She is passionate about holistic health and wellness, and has additional training in teaching, Reiki, and Tapping/ Emotional Freedom Technique. Her research interests include resiliency, psychoneuroimmunology, neuroplastic pain, placebo/ nocebo effect, and bioenergy therapies.  The views she expresses are her own, and do not reflect any affiliation.

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Medically reviewed by Dr. Stephen Matta, DO, MBA CAQSM and Mary Anne Matta, MS, MA, LAC

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