How Healthy Hair Growth Happens: What Fuels Stronger, Fuller Hair
Hair Growth Is a Complex Biological Process—Not a Mystery
If you've ever wondered why your hair grows quickly at some times and barely at all at others, you're not alone. Hair growth is one of the most talked-about topics in beauty, yet often the least understood.
Despite the endless list of products claiming to grow hair faster, longer, or thicker, true healthy hair growth starts well beneath the surface. It’s not about overnight miracles—it’s about how your follicles function, how well your scalp is supported, and how consistently you protect each stage of the hair cycle.
This guide breaks down how hair actually grows, what influences that process, and what you can do—through care, ingredients, and habits—to support fuller, healthier strands over time.
The Hair Growth Cycle: A Natural Rhythm
Hair doesn’t grow randomly. It follows a well-defined biological rhythm that includes four phases:
1. Anagen (Growth Phase)
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Lasts 2–7 years
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Determines how long your hair can grow
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About 85–90% of your hair is in this phase at any time
During anagen, hair cells divide rapidly at the base of the follicle. Blood vessels in the scalp feed the follicle oxygen and nutrients. The longer this phase lasts, the longer and healthier your hair can grow.
2. Catagen (Transition Phase)
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Lasts about 2–3 weeks
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Hair growth stops
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Follicle detaches from the blood supply
This is a short resting phase where the follicle shrinks and prepares for the next cycle.
3. Telogen (Resting Phase)
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Lasts 3–4 months
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Hair remains in the follicle but doesn’t grow
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Eventually, the strand is pushed out to make room for a new one
This is when hair naturally sheds. About 10–15% of your strands are in this phase at any time.
4. Exogen (Shedding Phase)
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The actual release of the old strand
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You may shed 50–100 hairs per day during this phase
Understanding this cycle helps explain why hair growth isn’t instant and why patience and consistency are key when trying to grow healthier hair.
What Determines How Well Your Hair Grows?
Healthy hair growth is influenced by both internal and external factors.
Internal Factors:
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Genetics: Determines growth speed, density, and maximum length
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Hormones: Androgens like DHT can shrink follicles and shorten the anagen phase
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Nutrition: Vitamins and minerals fuel cell division and follicle activity
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Blood circulation: Delivers oxygen and nutrients to growing follicles
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Stress and sleep: Affect hormone levels and growth cycles
External Factors:
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Scalp care: A balanced, hydrated scalp supports healthier follicles
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Product use: Harsh shampoos or chemical buildup can block follicle function
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Environment: UV, pollution, and toxins degrade hair quality over time
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Styling practices: Heat, tight hairstyles, and friction can cause mechanical stress
When these factors are in balance, your hair has the best possible environment to grow strong, resilient, and full.
The Role of the Scalp in Hair Growth
Think of your scalp like soil—and your hair as the plant. If the soil is inflamed, dry, or nutrient-depleted, the plant struggles. The same applies to your scalp.
A 2020 study published in the Journal of Clinical and Aesthetic Dermatology found that chronic scalp inflammation—due to buildup, irritation, or microbial imbalance—can significantly reduce hair density and slow growth (Martinez et al., 2020).
Healthy scalp = healthy hair.
That’s why Glisn’s Grow Stronger Hair Shampoo focuses on the scalp first, using biotin and hyaluronic acid to nourish the follicle environment and optimize conditions for growth.
Key Nutrients That Fuel Hair Growth
Just like your skin, your hair needs the right nutrients to thrive. Some of the most important include:
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Biotin (Vitamin B7): Essential for keratin production. Deficiency is linked to hair thinning and breakage (Dhurat & Sukesh, 2016).
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Iron: Low levels can cause telogen effluvium, especially in women.
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Zinc: Supports repair and oil regulation in the follicle.
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Vitamin D: Plays a role in the anagen phase. Deficiency may lead to slower growth.
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Protein: Hair is made of keratin, a protein. Inadequate protein in your diet can lead to dullness and shedding.
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Hyaluronic Acid: While it doesn’t grow hair directly, it hydrates the scalp and hair shaft, reducing dryness and brittleness (Fu et al., 2019).
This is why a well-rounded approach—including smart topical products and a nutrient-dense diet—is the most effective strategy for hair growth.
How Hormones Impact Hair Growth (and Loss)
Hormones affect hair at the follicular level. Androgens like DHT (dihydrotestosterone) shorten the anagen phase and shrink follicles over time, leading to thinner, weaker hair. This is especially true in androgenetic alopecia (pattern hair loss).
For women, hormonal shifts related to:
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Menopause
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Thyroid disorders
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PCOS
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Postpartum periods
can all trigger shedding or slower growth.
Supportive ingredients like ginger root extract, niacinamide, and biotin help balance the scalp and buffer some of these changes, creating a more supportive environment for growth—even during hormone-related fluctuations.
How Long Does Hair Growth Actually Take?
The average person’s hair grows about half an inch per month, or 6 inches per year. But that growth can be affected by:
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Genetics
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Hormones
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Stress
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Diet
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Scalp inflammation
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Consistency of care
That’s why products promising “2 inches in a week” are misleading. Instead of quick fixes, the goal should be to lengthen the anagen phase and keep follicles healthy and active.
What Slows Down Hair Growth?
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Scalp buildup: From styling products, oils, or dead skin
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Chronic inflammation: Can shut down follicle activity
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Vitamin or protein deficiencies
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Harsh ingredients: Like sulfates, which disrupt the scalp microbiome
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Poor circulation: Limits oxygen and nutrient delivery to the follicle
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Tight hairstyles: Cause traction and long-term follicle damage
A consistent routine that cleanses gently, nourishes deeply, and protects consistently is the most effective path forward.
How to Support Healthy Hair Growth, Step-by-Step
1. Start with the Scalp
Use a gentle shampoo that supports follicle health. Glisn’s Grow Stronger Hair Shampoo includes biotin to promote keratin support and hyaluronic acid to hydrate the scalp without weighing it down.
2. Feed the Follicle
Get your nutrients from both food and topical delivery. Foods rich in iron, zinc, protein, and omega-3s support internal growth, while formulas that include niacinamide, panthenol, and ginger root extract help externally.
3. Be Gentle With Styling
Minimize heat, tugging, and chemical processes. Air dry when possible, use heat protectant, and avoid tight ponytails or braids.
4. Exfoliate the Scalp Weekly
Use a gentle scalp scrub or exfoliating treatment once a week to prevent buildup and improve product absorption.
5. Be Consistent
Results take time. Most clinical studies show improvements after 12–16 weeks of consistent topical use. Stick with your routine, and support it with sleep, hydration, and stress management.
The Glisn Philosophy: Haircare That Starts at the Root
At Glisn, we believe healthy hair is grown, not made. That’s why we formulate with a skincare-meets-haircare mindset—focusing on the health of the scalp, the integrity of the strand, and the consistency of the cycle.
Our Grow Stronger Hair Shampoo delivers:
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Biotin for keratin support
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Hyaluronic acid for deep hydration
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Gentle surfactants to cleanse without stripping
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Scalp-supportive botanicals like ginger extract
It’s haircare that thinks like skincare—formulated for results, not promises.
Final Thoughts: Hair Growth Is a Journey, Not a Trend
Healthy hair growth isn’t about hacks. It’s about supporting biology with science-backed care. By understanding how hair grows, what slows it down, and what it truly needs to thrive, you can build a routine that supports real results—without guesswork or false hope.
Whether you’re trying to grow out your hair, recover from postpartum shedding, or simply want stronger, shinier strands—focus on what’s happening beneath the surface, and care for your scalp the way you do your skin.
Growth will follow.
Sources & Citations
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Martinez, L. et al. (2020). Scalp Health and Hair Growth: Role of Inflammation. Journal of Clinical and Aesthetic Dermatology.
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Dhurat, R., & Sukesh, M. (2016). Biotin in Hair Growth: A Clinical Perspective. Dermatology Practical & Conceptual.
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Fu, J., et al. (2019). Moisture Retention Effects of Hyaluronic Acid in Scalp and Hair Care. Journal of Cosmetic Dermatology.
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D’Souza, P., & Rao, A. (2020). Hair Care Ingredients: Mechanisms and Efficacy. International Journal of Trichology.
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Cosmetic Ingredient Review Expert Panel (2021). Safety Assessment of Topical Haircare Ingredients in Biotin-Based Products.
