The Science of Hair Growth: Why Some Guys Can’t Grow Long Hair Easily

Nov 17

Have you ever wondered why some men can grow thick, flowing hair while others struggle to get past a few inches before it stops—or worse, starts thinning out? You’re not alone. Hair growth isn’t just about genetics; it’s influenced by science, biology, and even your daily habits.

At In The Cut Barbershop in Vancouver, we’ve seen all types of hair growth patterns—from guys who can rock shoulder-length locks to those whose hair just won’t cooperate past a certain point. Understanding how hair grows (and why it sometimes doesn’t) can help you take better care of it and even maximize your growth potential.

1. Understanding How Hair Grows

Hair growth happens in cycles, and these cycles determine how long your hair can actually get. Every strand on your head is going through one of three main stages at any given time:

Anagen (Growth Phase): This is when your hair actively grows. It can last anywhere from 2 to 6 years, depending on genetics. The longer your anagen phase, the longer your hair can grow.
Catagen (Transition Phase): Lasts about 2–3 weeks. The hair stops growing and detaches from the follicle’s blood supply.
Telogen (Resting Phase): Lasts about 3 months. The old hair sheds to make room for new growth.

If your growth phase is shorter than average, your hair will naturally reach a limit—and that’s why some men can’t grow long hair easily.

2. The Role of Genetics

Like many traits, your genetic makeup plays a huge part in your hair growth potential. If the men in your family have shorter or thinner hair, there’s a good chance your follicles follow the same pattern.

Here’s what genetics can influence:

Growth rate: Some men’s hair grows faster (about 1.5 cm/month), while others grow slower.
Growth cycle length: Determines how long your hair can grow before it sheds.
Hair thickness: Thicker strands make hair appear fuller and longer, even if it grows at the same rate.
Balding or thinning tendency: Genetic sensitivity to hormones like DHT can cause hair to miniaturize over time.

While you can’t change your genetics, understanding them helps you manage expectations—and find the best haircut for your natural growth pattern.

3. Hormones and Hair Growth

Your hormones also play a key role in how your hair behaves. The main hormone affecting male hair growth is Dihydrotestosterone (DHT), a derivative of testosterone.

Here’s how DHT affects your hair:

It can shorten the anagen phase, meaning your hair grows for a shorter time before shedding.
It causes hair follicles (especially at the crown and hairline) to shrink over time, leading to thinner, finer hair.

That’s why men often experience receding hairlines or thinning on top, while still having thick hair on the sides and back—the follicles in those areas are less sensitive to DHT.

Managing stress, maintaining a healthy lifestyle, and using DHT-blocking shampoos or treatments can help slow this process.

4. Nutrition and Health Matter More Than You Think

Your diet and overall health have a direct impact on your hair’s growth rate and strength. Hair is made mostly of a protein called keratin, so your body needs the right nutrients to produce it effectively.

Nutrients essential for healthy hair growth:

Protein: Builds the structure of your hair (found in eggs, fish, and lean meats).
Iron & Zinc: Improve circulation and follicle strength.
Biotin & Vitamin B: Support keratin production.
Vitamin D: Encourages new follicle growth.
Omega-3 fatty acids: Keep your scalp hydrated and healthy.

If your diet lacks these nutrients, your hair can become weaker, grow slower, or even shed more easily.

5. Hair Care Habits That Can Hold You Back

Even if your genetics and health are on your side, bad grooming habits can slow down or damage growth.

Common mistakes men make:

Overwashing: Stripping natural oils makes hair brittle.
Using harsh shampoos: Sulfates can weaken follicles.
Skipping conditioner: Dry hair breaks more easily, making it seem like it’s not growing.
Excessive heat or chemical treatments: Damage the cuticle and stunt growth.

Pro tip:
Stick to a gentle, sulfate-free shampoo and use conditioner regularly to keep your hair hydrated and strong. If you’re unsure which products work best for your hair type, your barber can guide you.

6. Can Barbers Help You Grow Healthier Hair? Absolutely.

You might not think of your barber as part of your hair growth journey—but a skilled barber plays a key role. Regular trims remove split ends, keeping your hair healthy and preventing breakage that makes it look like it’s “stuck” at a certain length.

At In The Cut Barbershop, we also recommend scalp treatments that:

Improve blood circulation for stronger follicles
Remove buildup that can clog pores
Balance your scalp’s oil production

Small steps like these can go a long way toward helping your hair reach its full potential.

Conclusion

The science of hair growth proves that while genetics and hormones set the foundation, your habits and care routine make all the difference. You may not be able to change how fast your hair grows, but you can make it stronger, healthier, and fuller with the right approach.

At In The Cut Barbershop in Vancouver, we’re not just about haircuts—we’re about helping you look and feel your best. Our expert barbers understand men’s hair from root to tip and can guide you toward a style and care routine that works for your growth goals.

Book your appointment at In The Cut Barbershop in Vancouver today—and let our professionals help you get the most out of your hair, no matter its length or texture.