What Makes Hair Stronger? The Science Behind Healthy, Resilient Hair
- Ryan Chynoweth
- Jul 30
- 5 min read
Healthy, strong hair is something many people aspire to achieve, but what actually makes hair stronger? Is it expensive treatments, miracle ingredients or simply good genetics?
The truth is that strong, healthy-looking hair is influenced by a combination of genetics, overall health, nutrition, scalp condition and how you care for your hair every day. While cosmetic products cannot change the genetics of hair growth, they can help improve the condition of the hair fibre, protect it from damage and support a healthy scalp environment where hair naturally grows.
In this guide, we'll explore the science behind stronger hair and explain the everyday habits that can help maintain healthier-looking hair.
Understanding Hair Structure
To understand what makes hair stronger, it's important to first understand how hair is built.
Each hair strand is primarily composed of a structural protein called keratin, which accounts for approximately 90–95% of the hair fibre (Robbins, 2012). Hair consists of three main layers:
The cuticle – the protective outer layer made up of overlapping scales.
The cortex – the thick middle layer that provides strength, flexibility and colour.
The medulla – the central core, which is absent in some finer hairs.
The cuticle acts like armour for the hair shaft. When it remains smooth and intact, hair appears shinier, feels softer and is less likely to break. Damage to the cuticle exposes the cortex beneath, making hair weaker and more susceptible to splitting and breakage (Robbins, 2012).
Healthy Hair Starts with a Healthy Scalp
Many people focus entirely on the hair they can see, but every strand begins beneath the skin.
The scalp contains approximately 100,000 hair follicles, each functioning independently through its own growth cycle (Paus and Cotsarelis, 1999). A healthy scalp provides the environment necessary for normal hair growth by supporting the hair follicle throughout the anagen (growth) phase.
Maintaining scalp health involves:
Regular cleansing to remove excess sebum, sweat and environmental pollutants.
Supporting the skin barrier with appropriate hydration.
Minimising excessive build-up from styling products.
Avoiding unnecessary irritation from harsh treatments.
A clean, balanced scalp helps create the optimal environment for healthy-looking hair.
Protein Is Essential for Strong Hair
Because hair is composed predominantly of keratin, adequate dietary protein is essential for producing new hair.
Hair follicles are among the body's most metabolically active tissues. During periods of inadequate protein intake, the body prioritises essential organs over hair production, which may contribute to increased shedding and slower growth (Almohanna et al., 2019).
Protein-rich foods include:
Lean poultry
Fish
Eggs
Beans
Lentils
Dairy products
Soy products
A balanced diet generally provides sufficient protein for healthy hair production in most individuals.
Vitamins and Minerals Support Normal Hair Growth
Hair follicles require a continuous supply of nutrients to function normally.
Several vitamins and minerals have recognised roles in maintaining healthy hair, although supplementation should generally only be considered where a deficiency has been identified.
Important nutrients include:
Iron
Iron deficiency is one of the most common nutritional deficiencies associated with diffuse hair shedding, particularly in women (Almohanna et al., 2019).
Vitamin D
Vitamin D plays a role in the normal cycling of hair follicles, although the relationship between deficiency and hair loss remains an area of ongoing research (Guo and Katta, 2017).
Zinc
Zinc contributes to normal protein synthesis and cellular repair, both of which are important for healthy hair follicles (Guo and Katta, 2017).
Biotin
Biotin is frequently marketed for hair health, but evidence suggests supplementation is most beneficial in individuals with a true biotin deficiency, which is relatively uncommon in healthy populations (Patel et al., 2017).
Protecting the Hair Fibre
Hair naturally becomes weaker when repeatedly exposed to physical and chemical stress.
Common causes of damage include:
Excessive heat styling
Frequent bleaching or colouring
Tight hairstyles causing tension
Rough towel drying
Aggressive brushing, particularly when wet
These practices can damage the cuticle, increasing friction and making hair more prone to breakage (Robbins, 2012).
Simple protective habits include:
Using lower heat settings when styling.
Applying heat protection products.
Gently detangling with a wide-toothed comb.
Avoiding hairstyles that place prolonged tension on the scalp.
Sleeping on silk or satin pillowcases to reduce friction.
Why Conditioner Makes Hair Stronger
Although conditioner does not change the biology of hair growth, it plays an important role in protecting the hair shaft.
Conditioners work by coating the hair fibre, smoothing the cuticle and reducing friction between strands (Robbins, 2012). This can help:
Reduce breakage
Improve manageability
Increase shine
Reduce static electricity
Improve the appearance of damaged hair
Using conditioner after shampooing helps protect the hair fibre from everyday wear and tear.
The Role of Scalp Serums
Scalp serums are designed to care for the skin of the scalp rather than the hair shaft itself.
A well-formulated scalp serum can:
Help maintain scalp hydration.
Support scalp comfort.
Deliver conditioning ingredients directly to the scalp.
Complement a consistent scalp care routine.
While cosmetic scalp serums are not medicines and should not be expected to treat hair loss, maintaining a healthy scalp may help support the environment in which healthy-looking hair grows.
The Importance of Consistency
Healthy-looking hair develops over time.
Hair grows at an average rate of approximately 1 cm per month, although growth rates vary between individuals (Sinclair, 2015). Because of this, improvements in hair condition often become noticeable only after several weeks or months of consistent care.
Rather than relying on occasional intensive treatments, regular habits are more likely to support stronger, healthier-looking hair over time.
A consistent routine might include:
Gentle cleansing appropriate for your scalp type.
Regular conditioning.
Daily scalp care where appropriate.
Protecting hair from unnecessary damage.
Maintaining a balanced diet and healthy lifestyle.
Lifestyle Factors That Influence Hair Strength
Several everyday factors can influence the appearance and resilience of hair.
These include:
Sleep quality
Psychological stress
Smoking
UV exposure
Nutrition
Hormonal changes
Certain medical conditions
Ageing
While some of these factors cannot be modified, maintaining an overall healthy lifestyle supports normal hair biology and overall wellbeing (Almohanna et al., 2019).
The Bottom Line
There is no single ingredient or product that makes hair stronger overnight.
Strong, healthy-looking hair is the result of healthy follicles, an intact hair fibre and consistent care over time. Looking after your scalp, protecting the hair shaft from damage, maintaining a balanced diet and following a regular haircare routine all contribute to improving the appearance and resilience of your hair.
At Bloom & Root, we believe healthy-looking hair starts beneath the surface. By combining science-led formulations with consistent daily care, you can help create the ideal environment for stronger, healthier-looking hair over time.
Rooted in science. Designed for confidence.
References
Almohanna, H.M., Ahmed, A.A., Tsatalis, J.P. and Tosti, A. (2019) 'The role of vitamins and minerals in hair loss: A review', Dermatology and Therapy, 9(1), pp. 51–70. https://doi.org/10.1007/s13555-018-0278-6
Guo, E.L. and Katta, R. (2017) 'Diet and hair loss: Effects of nutrient deficiency and supplement use', Dermatology Practical & Conceptual, 7(1), pp. 1–10. https://doi.org/10.5826/dpc.0701a01
Patel, D.P., Swink, S.M. and Castelo-Soccio, L. (2017) 'A review of the use of biotin for hair loss', Skin Appendage Disorders, 3(3), pp. 166–169. https://doi.org/10.1159/000462981
Paus, R. and Cotsarelis, G. (1999) 'The biology of hair follicles', New England Journal of Medicine, 341(7), pp. 491–497. https://doi.org/10.1056/NEJM199908123410706
Robbins, C.R. (2012) Chemical and Physical Behavior of Human Hair. 5th edn. Berlin: Springer.
Sinclair, R. (2015) 'Hair shedding in health and disease', Australian Prescriber, 38(5), pp. 152–155. https://doi.org/10.18773/austprescr.2015.055
Comments