Hair 101
Learn the basics of hair biology and how it grows.
Hair 101: The Basics of Hair Biology and How It Grows
Whether you’re noticing changes in your hair or just curious about how those strands on your head actually work, understanding the basics of hair biology is the first step. In this guide, we’ll break down the science of hair in a way that’s easy to understand—no biology degree required.
What Is Hair Made Of?
Hair might seem simple, but it’s surprisingly complex. Each strand is primarily made of keratin, a strong, fibrous protein also found in nails and skin. Once the hair leaves your scalp, it’s technically “dead”—but the follicle it grows from is alive and working hard.
Meet the Hair Follicle
The hair follicle is a tiny, tunnel-like structure in the skin. At the base is the hair bulb, where living cells multiply to form the hair strand. Just below is the dermal papilla, which delivers blood and nutrients, acting like a command center for hair growth.
The Hair Growth Cycle
Hair grows in a repeating cycle, not all at once. Understanding these phases explains why we shed hair daily:
1. Anagen (Growth Phase)
Lasts 2–7 years. The hair is actively growing. Most of the hair on your head is in this phase.
2. Catagen (Transition Phase)
A brief 2–3 week period where growth slows and the follicle shrinks.
3. Telogen (Resting Phase)
Lasts about 3 months. The hair rests, then sheds to make way for new growth.
Why Hair Thins or Stops Growing
Several factors can disrupt this cycle:
- Genetics: Most common cause (e.g., male or female pattern hair loss)
- Hormonal changes: Pregnancy, menopause, thyroid issues, etc.
- Stress & illness: Can cause sudden shedding (telogen effluvium)
- Nutritional deficiencies: Especially iron, protein, vitamin D, and B12
- Scalp conditions: Inflammation, scarring, or infections
Why Hair Thins or Stops Growing
Several factors can disrupt this cycle:
- Genetics: Most common cause (e.g., male or female pattern hair loss)
- Hormonal changes: Pregnancy, menopause, thyroid issues, etc.
- Stress & illness: Can cause sudden shedding (telogen effluvium)
- Nutritional deficiencies: Especially iron, protein, vitamin D, and B12
- Scalp conditions: Inflammation, scarring, or infections
Can Hair Grow Back?
Yes—especially if the hair follicle is still alive. The earlier you intervene, the more successful the outcome.
Common treatment options include:
- Topical and oral medications
- Nutritional support
- Laser therapy
- PRP (Platelet-Rich Plasma) injections
- Hair transplants
At Hair Medicine Institute, we design custom, evidence-based plans for every type of hair loss—whether you’re looking to slow shedding or achieve full restoration.
Ready to Take the First Step?
If you’re noticing more hair in the brush or a thinning hairline in the mirror, don’t wait. The sooner you act, the more options you have. At Hair Medicine Institute, we’re here to guide you with medical precision and personalized care.
Schedule your consultation today and take the first step toward stronger, healthier hair.