This myth is false!

A recently published dermatological survey confirms that health misinformation like this is deeply ingrained and ubiquitous in society [1]. However, upon closer inspection, there is surprisingly little truth behind this supposed wisdom. In fact, scientific evidence has long contradicted this assumption: shaving studies, including the first clinical trial in 1928, have demonstrated that shaving has no effect on hair growth [2]. Subsequent studies have also confirmed these findings, establishing that shaving does not affect either the growth rate or the hair structure [3].

A brief look at the physiology of our hair reveals why these studies reached this conclusion. The hair follicles, anchored in the scalp, function as a "hair factory" and contain matrix keratinocytes – highly active cells that enable the growth of new hair. The visible hair shaft, on the other hand, consists of completely keratinized, dead cells. This means that the hair tips are biologically inactive and cannot respond to cutting [4]. This becomes even clearer when you look at the life cycle of your hair. It comprises three phases: the anagen phase (growth), the catagen phase (regression), and the telogen phase (resting) [5]. Did you know that right now, around 80 to 90% of your scalp hair is in this "resting" phase? [4,5] The duration of the anagen phase largely determines how long a person's hair can grow – it varies individually and is regulated by biological factors (and certainly not by cutting, even if we sometimes wish it would ;)) [4]. The hair cycle is also affected by various factors such as hormones, stress or certain medications [5].

Ultimately, split ends make hair more prone to breakage. And this is precisely where the practical benefit of regular trims comes in: a haircut is the only effective way to remove split ends and prevent further damage. Fewer split ends mean less breakage. This makes hair appear longer, thicker, and healthier – giving the impression that it's growing faster. Therefore, you should make sure to trim your ends regularly to maintain hair quality in the long term and minimize length loss due to breakage [6].

Quellen:

[1] Belcadi J, Oulad Ali S, Zeghari Z, Senouci K, Meziane M. Preconceived ideas in hair care. International Journal of Women’s Dermatology. 2025; 11(2): e194. doi:10.1097/JW9.0000000000000194.

[2] Trotter M. Hair Growth and Shaving. The Anatomical Record. 1928; 37(4): 373-9. doi:10.1002/ar.1090370405.

[3] Lynfield YL, Macwilliams P. Shaving and hair growth. The Journal of Investigative Dermatology. 1970; 55(3): 170-2. doi: 10.1111/1523-1747.ep12280667.

[4] Cuevas-Diaz Duran R, Martinez-Ledesma E, Garcia-Garcia M, Bajo Gauzin D, Sarro-Ramírez A, Gonzalez-Carrillo C, Rodríguez-Sardin D, Fuentes A, Cardenas-Lopez A. The Biology and Genomics of Human Hair Follicles: A Focus on Androgenetic Alopecia. International Journal of Molecular Sciences. 2024; 25(5): 2542. doi: 10.3390/ijms25052542.

[5] Oh JW, Kloepper J, Langan EA, Kim Y, Yeo J, Kim MJ, Hsi TC, Rose C, Yoon GS, Lee SJ, Seykora J, Kim JC, Sung YK, Kim M, Paus R, Plikus MV. A guide to studying human hair follicle cycling in vivo. The Journal of Investigative Dermatology. 2016; 136(1): 34-44. doi: 10.1038/jid.2015.354.

[6] Robbins CR. Chemical and Physical Behavior of Human Hair. 5th ed: Springer-Verlag Berlin Heidelberg; 2012.