Understanding Hair Growth: How Your Hair Really Grows
Do you dream of long and strong hair? Everyone does!
But picking random products with the hope of boosting hair growth can sometimes not be as rewarding as quick fixes and randomly selected products might not operate as expected due to differences in hair and scalp conditions or the hair's needs.
So, a clear understanding of the science behind hair growth, the hair growth cycle, the factors that influence the growth process and the choice of ingredients based on hair type and priorities is essential while taking proper hair care decisions.
Without further ado, let’s dive in and find out the secrets of hair growth!
What is Hair?
Hair has been defined by Hoover, Alhajj and Flores (2023) as a complex and dead fibrous protein structure that is composed of keratin, which grows out of the follicles present in the skin. Hair serves as a protective covering and an insulating layer for the body.
Some of the key aspects of the human hair are:
The structure of a hair is comprised of the cuticle (the protective layer), cortex (the layer contributing to the hair’s colour) and medulla (the innermost core) (Martel et al., 2024).
Every hair strand is primarily made of the protein keratin along with different compositions of carbon, oxygen, nitrogen, hydrogen and sulphur (Crlab.com, 2026).
The Science Behind Hair Growth
Hair growth has been identified by Lin, Zhu and He (2022) as a complex biological process that begins with the growth of follicles in the scalp, where the hair bulbs are located at the base. The hair bulb is a place where different living cells rapidly divide, being nourished by nutrients and oxygen that are carried and delivered by blood circulation.
With the formation of new cells, the older cells are pushed upwards, which is later hardened through the process, commonly known as keratinization, while emerging from the scalp as visible strands (Deo and Deshmukh, 2018). As hair exits the scalp, it emerges as dead tissue. Therefore, external products are often targeted towards protecting, smoothing and strengthening the hair shaft rather than repairing it on the cellular level.
Stages of Hair Growth
Hair growth is said to follow a cycle that involves four key stages, which are referred to as Anagen, Catagen, Telogen and Exogen. The stages cover the full life cycle of hair growth, fall and regrowth.
Anagen (Active Growth Phase):
This is the stage where hair root cell division is quick and forms a complete hair strand from the hair follicles. It takes about 2-8 years for the hair strands to grow in this stage (Natarelli, Gahoonia and Sivamani, 2023).
Catagen (Transition Phase):
A short 2–3-week phase where the hair growth stops as the hair follicles regress and detach from the dermal papilla, thereby the hair detaches from the blood supply, creating a ‘club’ hair (Natarelli, Gahoonia and Sivamani, 2023).
Telogen (Resting Phase):
Post the Catagen phase, the dermal papilla moves upwards towards the hair follicle bulge, and a new hair starts its formation underneath. It takes about 3-4 months as the follicle rests (Natarelli, Gahoonia and Sivamani, 2023).
Exogen (Shedding Phase):
This is the final phase of the hair growth cycle, where the old hair falls out as the new hair tries and makes its way upward.
Factors Influencing Hair Growth
Genetics:
Genes help determine the hair’s natural characteristics to a certain extent, starting with thickness, texture, density and the point at which it would grow. According to Asfour, Cranwell and Sinclair (2023), the genes on the X chromosomes, particularly the AR (androgen receptor) gene helps identify the manner in which the hair follicles respond to the dihydrotestosterone (DHT), which can lead to miniaturization of the hair follicles, leading to androgenetic alopecia. On the contrary, Kuga et al., (2016) observed that genes regulate keratins and desmosomes, which influence the strength and texture of the hair strands. Genes have also been found to dictate the anagen (growth) phase, thereby determining the length of hair growth. So, genes play a crucial role in influencing the strength, texture, length and breakage characteristics of hair.
Hormones:
Hormonal balance is quintessential to ensure proper hair growth. It was observed from the research by Healthline (2026) that certain androgens like DHT can potentially miniaturize the hair follicles, resulting in subsequent breakage. Contrarily, it was found that medical conditions such as thyroid disorders, pregnancy, or PCOS can often affect hair growth. Also, Sharpley, McFarlane and Slominski (2011) stated that stress-induced release of the Cortisol hormone forces the hair follicles to prematurely enter the telogen phase, affecting the total scope of hair growth.
Nutrition:
Nutrition is a primary factor that influences the degree of hair growth. It has been found in the research by Guo and Katta (2017) that hair follicles are the most active cells in the human body; therefore, they require a steady supply of nutrients to keep thriving, whereas a deficiency in the supply of nutrients can affect the scope of hair growth. Trüeb (2021) observed that protein is one of the most needed nutrients for improving hair growth as it helps in stimulating the keratin production, which in turn supports the structural integrity of the strands. Iron has been identified by Elnady et al., (2025) as another most needed nutrient, as it helps in improving blood circulation while delivering nutrients and oxygen to the hair follicles for steady growth, whereas biotin and different vitamins are necessary to support scalp and hair health. Therefore, deficiency in the most needed nutrients can disrupt the hair growth cycle, pushing more hair to the telogen or resting phase.
Scalp Health:
Healthy scalp is the ultimate gateway, creating a positive environment for hair growth. Trüeb et al., (2018) stated that different scalp issues associated with dandruff, excess oil, irritation, inflammation, clogged follicles etc. are capable of disrupting continuous hair growth by weakening of the hair follicles. Therefore, effective scalp care is essential through cleansing, gentle exfoliation and proper hydration, which help in balancing the natural oil production and remove dirt for instilling continuous hair growth.
How to Choose Your Hair Growth Products
People find it confusing to select the best suited products like oils, shampoos or serums for influencing better hair growth. To make it simple, one must select only those products that correlate with particular hair needs.
Different products are available in the market that are specifically targeted towards catering to hair needs during the different stages of the hair growth cycle. Therefore, selecting the best suited product requires considerations in matters like hair growth needs, scalp condition, and hair type, rather than simply going by the trend.
Here’s what you must do:
Understand the Hair Growth Needs:
Hair growth varies between different individuals based on genetics, hormones and the standard of living. Henceforth, hair growth needs can be divided into three categories like accelerated hair growth, thick and dense hair and strong breakage-free hair.
Therefore, selecting products according to the hair growth priorities is particularly useful.
Choose products based on Scalp Health:
Healthy hair growth is mostly influenced by scalp health (Nayak et al., 2017). So, considering scalp health is essential to maintain a balanced environment that aids in improving the chances of hair growth. For instance, if an individual has an oily scalp, using lightweight products that prevent clogging of the pores is essential, whereas an individual with a sensitive scalp must select soothing and non-irritating products.
Therefore, the art of selecting the best suited product begins with a deep understanding of the scalp condition and the hair growth goals.
Select Products with Growth Ingredients:
Focusing on products that are infused with different hair growth ingredients like caffeine, peptides, proteins, biotin and natural oils has been found to be effective to boost hair growth. Bansal, Manchanda and Pandey (2012) found that Caffeine helps stimulate the hair follicles while Peptides and proteins help strengthen strands by contributing to improve the structural integrity. Alternatively, Patel et al., (2025) found that Biotin and natural oils like rosemary, castor etc. helps improve the keratin structure and boost scalp circulation to ensure continuous delivery of nutrients and oxygen to the hair follicles for stronger hair growth.
Matching Products to the Hair Type:
The type of hair determines how a product would work, so, firstly, understanding the hair type is essential before picking a product for daily use. For instance, if an individual has fine hair then lightweight serums and non-greasy oils will be perfect, whereas opting for deep conditioning products and richer oils is essential to care for thick or coarse hair. Therefore, the type of hair of an individual greatly influences the choice of hair growth products.
Our Hair Growth Master: Alopex Penta
An advanced hair regrowth solution that is targeted to fight the root causes of hair fall while promoting new hair growth. With the goodness of powerful hair growth ingredients like Korean Red Ginseng, Biotin and Vitamin E, it stimulates the weakened hair follicles, improves blood circulation in the scalp and strengthens the roots for visible long and strong hair. It miraculously blocks DHT with Rosemary Essential Oil and Caffeine while amino acids and plant proteins assist in nourishing the hair shaft, repairing damage and improving hair density, to prevent breakage and thinning. Additionally, charged with Pentavitin and other humectants, the solution offers long-lasting hydration to balance the scalp environment, thereby boosting hair growth.
Conclusion: Gain Access to Healthy Hair Growth
Hair growth is a natural cycle which is evidently influenced by factors like genetics, hormones, nutrition and scalp health conditions. Although different products are currently available to protect and strengthen the hair strands, true hair growth actually occurs at the follicular level.
Understanding the hair growth cycle assists in finding the targeted products that are best suited for instilling continuous hair growth. So, instead of quick fixes, consider several criteria like hair type and scalp condition before picking a product with the expectation of improving hair growth.
At an end note, hair growth is all about selecting the best-suited products and a lot of patience to turn the hair growth into a healthy process.
References:
- Asfour, L., Cranwell, W. and Sinclair, R., 2023. Male androgenetic alopecia. Endotext [Internet]. https://www.ncbi.nlm.nih.gov/books/NBK278957/
- Bansal, M., Manchanda, K. and Pandey, S.S., 2012. Role of caffeine in the management of androgenetic alopecia. International journal of trichology, 4(3), pp.185-186. https://pmc.ncbi.nlm.nih.gov/articles/PMC3500065/
- Crlab.com., 2026. Structure and chemical composition of hair. Crlab. https://crlab.com/en_en/scientific-area/hair-and-scalp/structure-and-chemical-composition-of-hair/?srsltid=AfmBOooZGgV77J7iIMChrN8jPcB3QA-PJb0Ke_ufloEH71U_Xso0exwD
- Deo, P.N. and Deshmukh, R., 2018. Pathophysiology of keratinization. Journal of oral and maxillofacial pathology, 22(1), pp.86-91. https://pmc.ncbi.nlm.nih.gov/articles/PMC5917548/
- Elnady, R.E., Abdon, M.S., Shaheen, H.R., Eladawy, R.M., Azar, Y.O. and Al Raish, S.M., 2025. The future of alopecia treatment: plant extracts, nanocarriers, and 3D bioprinting in focus. Pharmaceutics, 17(5), p.584. https://pmc.ncbi.nlm.nih.gov/articles/PMC12115063/
- Guo, E.L. and Katta, R., 2017. Diet and hair loss: effects of nutrient deficiency and supplement use. Dermatology practical & conceptual, 7(1), p.1. https://pmc.ncbi.nlm.nih.gov/articles/PMC5315033/
- Healthline., 2026. What You Need to Know About DHT and Hair Loss. Healthline. https://www.healthline.com/health/dht
- Hoover, E., Alhajj, M. and Flores, J.L., 2023. Physiology, hair. In StatPearls [Internet]. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK499948/
- Kuga, T., Sasaki, M., Mikami, T., Miake, Y., Adachi, J., Shimizu, M., Saito, Y., Koura, M., Takeda, Y., Matsuda, J. and Tomonaga, T., 2016. FAM83H and casein kinase I regulate the organization of the keratin cytoskeleton and formation of desmosomes. Scientific reports, 6(1), p.26557. https://www.nature.com/articles/srep26557.pdf
- Lin, X., Zhu, L. and He, J., 2022. Morphogenesis, growth cycle and molecular regulation of hair follicles. Frontiers in cell and developmental biology, 10, p.899095. https://www.frontiersin.org/journals/cell-and-developmental-biology/articles/10.3389/fcell.2022.899095/full
- Martel, J.L., Miao, J.H., Badri, T. and Fakoya, A.O., 2024. Anatomy, hair follicle. In StatPearls [Internet]. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK470321/
- Natarelli, N., Gahoonia, N. and Sivamani, R.K., 2023. Integrative and mechanistic approach to the hair growth cycle and hair loss. Journal of clinical medicine, 12(3), p.893. https://pmc.ncbi.nlm.nih.gov/articles/PMC9917549/
- Nayak, B.S., Ann, C.Y., Azhar, A.B., Ling, E.C.S., Yen, W.H. and Aithal, P.A., 2017. A study on scalp hair health and hair care practices among Malaysian medical students. International journal of trichology, 9(2), pp.58-62. https://pmc.ncbi.nlm.nih.gov/articles/PMC5551307/
- Patel, M.N., Tuli, N., Patel, N. and Merja, A., 2025. Rosmagain™ as a natural therapeutic for hair regrowth and scalp health: a double-blind, randomized, three-armed, placebo-controlled clinical trial. Cureus, 17(6). https://pmc.ncbi.nlm.nih.gov/articles/PMC12256010/
- Sharpley, C.F., McFarlane, J.R. and Slominski, A., 2011. Stress-linked cortisol concentrations in hair: what we know and what we need to know. Reviews in the Neurosciences, 23(1), p.111. https://pmc.ncbi.nlm.nih.gov/articles/PMC3381079/
- Trüeb, R.M., 2021. “Let food be thy medicine”: value of nutritional treatment for hair loss. International Journal of Trichology, 13(6), pp.1-3. https://pmc.ncbi.nlm.nih.gov/articles/PMC8647708/
- Trüeb, R.M., Henry, J.P., Davis, M.G. and Schwartz, J.R., 2018. Scalp condition impacts hair growth and retention via oxidative stress. International journal of trichology, 10(6), pp.262-270. https://pmc.ncbi.nlm.nih.gov/articles/PMC6369642/
