Healthy Hair Starts With Understanding the Basics
Before treatments, supplements, or advanced methods, it is important to understand how hair grows, why hair loss occurs, and what factors support healthy growth over the long term.
Most People Skip the Foundations
Many people immediately look for treatments while overlooking the biological foundations that support healthy hair. Without these in place, even the best treatments underperform.
Hair Biology
Hair is a biological tissue that depends on nutrients, hormones, blood flow, and cellular activity. It cannot thrive in an unhealthy internal environment.
Nutrition
Hair follicles are among the most metabolically active structures in the body. What you eat directly influences their ability to grow and maintain healthy strands.
Recovery & Sleep
Hair growth is slow and cumulative. Adequate sleep and recovery support the hormonal and cellular processes that drive healthy follicle activity.
Hormonal Balance
Consistency matters more than quick fixes. Hormonal balance underpins the hair cycle and supports every other intervention you might add over time.
The Hair Cycle Explained
Every strand of hair goes through a natural cycle of growth, transition, rest, and shedding. Understanding this cycle is key to understanding why treatments take time to work.
Anagen — Growth Phase
The active growth stage of the hair cycle, where cells in the follicle rapidly divide to produce new hair.
- Lasts between 2 and 7 years
- Determines your maximum hair length
- Around 85–90% of scalp hairs are in this phase at any time
- The primary target of most hair growth treatments
Catagen — Transition Phase
A brief transitional period where the follicle prepares to rest. Growth stops and the follicle begins to shrink.
- Lasts approximately 2–3 weeks
- The hair follicle detaches from its blood supply
- Only around 1–3% of hairs are in this phase at once
- Cannot be meaningfully extended by treatments
Telogen — Resting Phase
The hair remains in place but is no longer actively growing. The follicle is dormant and preparing for the next cycle.
- Lasts around 3 months
- Around 10–15% of hairs are in this phase
- Stress and illness can push more follicles into telogen
- The basis of telogen effluvium (see below)
Exogen — Shedding Phase
The old hair strand is released and shed naturally, making way for the next anagen phase to begin.
- Losing 50–100 hairs per day is considered normal
- Shedding is not the same as hair loss
- New growth begins from the same follicle
- The cycle then restarts from anagen
Key Takeaway
Hair growth improvements often take months because follicles must progress through these natural cycles. A treatment that starts working today won’t produce visible results until follicles complete their current cycle and enter a new anagen phase — typically 3 to 6 months later. Patience and consistency are essential.
Why Hair Loss Happens
Hair loss has many causes — and identifying yours is the most important step before exploring any treatment. Here are the most common patterns and conditions.
Androgenetic Alopecia
Also known as male or female pattern hair loss, this is the most common cause of hair loss worldwide. It is driven by a genetic sensitivity to dihydrotestosterone (DHT), a hormone derived from testosterone.
Over time DHT causes progressive follicle miniaturisation — follicles shrink and produce progressively thinner, shorter hairs until they eventually stop producing hair altogether.
- In men: typically begins at the temples and crown
- In women: diffuse thinning, often at the parting
- Gradual and progressive without intervention
- Responds well to DHT-blocking and growth-stimulating treatments
Telogen Effluvium
A temporary shedding condition where a large number of hair follicles are pushed into the telogen (resting) phase at the same time, resulting in diffuse shedding across the scalp.
Common triggers include:
- Illness or surgery
- Rapid weight loss
- Severe or prolonged stress
- Nutritional deficiencies
- Childbirth (postpartum shedding)
⌛ Important: shedding typically begins 2–4 months after the triggering event. This delay often causes confusion about the true cause. In most cases, shedding resolves on its own once the trigger is addressed.
Chronic Stress
Chronic stress can disrupt the hair cycle through several mechanisms. Elevated cortisol — the primary stress hormone — may contribute to follicle inflammation and push hairs into the telogen phase prematurely.
It is important to note that stress typically acts as a trigger or amplifier rather than the sole cause of hair loss. Managing stress is unlikely to reverse pattern hair loss alone, but it can reduce the severity of shedding and support overall scalp health.
- Contributes to telogen effluvium episodes
- May worsen existing androgenetic alopecia
- Chronic vs. acute stress have different effects
Hormonal Factors
Several hormonal conditions and changes can affect the hair cycle and lead to noticeable shedding or thinning. These are particularly relevant for women experiencing life transitions.
- Thyroid disorders (both hypo and hyperthyroidism)
- Postpartum hormonal shifts after childbirth
- Menopause and declining oestrogen levels
- Elevated testosterone or DHT-related effects
- PCOS (polycystic ovary syndrome) in women
⚕️ If you are experiencing persistent or significant hair loss, it is worth consulting a healthcare professional to rule out underlying hormonal or medical causes before beginning any treatment.
Hair Is Built From What You Eat
Hair follicles are among the most metabolically active structures in the body. They require a consistent supply of nutrients to sustain the rapid cell division that drives hair growth.
Protein
Hair consists primarily of keratin, a structural protein. Inadequate protein intake can directly impair hair growth and increase shedding.
Iron
One of the most common nutrient deficiencies associated with hair loss, particularly in women. Ferritin levels are a more reliable marker than standard iron tests.
Vitamin D
Plays a role in follicle cycling and immune regulation. Deficiency is widespread and often overlooked as a contributing factor in hair loss.
Zinc
Supports normal hair growth processes and tissue repair around the follicle. Both deficiency and excess supplementation can negatively affect hair.
| Nutrient | Why It Matters | Common Food Sources |
|---|---|---|
| Protein | Keratin — the primary structural component of hair — is a protein. Insufficient intake reduces the building blocks available for follicle activity. | Eggs, meat, fish, legumes, dairy, tofu |
| Iron | Ferritin (stored iron) supports follicle energy metabolism. Low levels are one of the most frequently identified deficiencies in women with hair loss. | Red meat, lentils, spinach, fortified cereals, tofu |
| Vitamin D | Involved in follicle cycling and immune function. Deficiency has been associated with various forms of hair loss. | Sunlight, oily fish, egg yolks, fortified foods, supplements |
| Zinc | Supports normal hair growth and repair processes around the follicle. Deficiency can result in shedding and brittle hair. | Oysters, pumpkin seeds, beef, chickpeas, cashews |
| Omega-3 Fatty Acids | Support general scalp and skin health, and may reduce follicle inflammation. | Oily fish, flaxseeds, chia seeds, walnuts |
| B Vitamins (incl. Biotin & B12) | Involved in cellular energy metabolism and red blood cell production. Deficiencies — particularly B12 — can contribute to hair shedding. | Eggs, meat, dairy, whole grains, leafy greens |
Lifestyle Factors That Support Growth
Beyond nutrition, several everyday habits create the conditions for healthy follicle activity and can meaningfully support the results of other interventions.
Sleep
Deep sleep is when tissue repair and hormonal regulation occur. Growth hormone — which supports cellular renewal — is released primarily during slow-wave sleep. Chronic sleep deprivation elevates cortisol and may worsen shedding.
Exercise
Regular physical activity improves overall circulation, including scalp blood flow, and helps regulate hormones including cortisol and insulin. Excessive high-intensity exercise without adequate nutrition can occasionally contribute to shedding.
Scalp Health
A clean, healthy scalp is the environment your follicles live in. Managing irritation, sebum buildup, and inflammation through regular gentle washing and avoiding harsh products supports long-term follicle health.
Minimising Damage
Excessive heat styling, aggressive brushing, tight hairstyles, and harsh chemical treatments can cause mechanical and structural damage that worsens the appearance of thinning. Gentle handling preserves the hair you have.
Your Foundations Checklist
Before exploring treatments, use this checklist to identify whether your foundations are in place. These are the factors most likely to be undermining your results if overlooked.
“Foundations aren’t the most exciting part of hair growth — but they’re the part that makes everything else work.”
— HairGrowthHubFoundations First. Then Optimisation.
Once the basics are in place, you are ready to explore the evidence-based treatments and advanced methods that work best when built on a solid foundation.