Elongation Factor: Protein involved in hair growth

ByDr. Celestine (Certified Trichologist)

What is Elongation Factor?

Elongation Factor is a measurement of how much a single hair strand can stretch before it breaks. It is a core function that determines your hair’s elasticity and overall health. Think of it like a rubber band’s stretchiness.

Most people miss this: Healthy hair can stretch up to 30% of its original length when wet before snapping back. I see this test reveal hidden damage long before split ends appear.

Why Elongation Factor Predicts Hair Breakage

Your hair’s cortex contains coiled proteins that unravel when stretched. This is your elongation factor in action. When these proteins are damaged, they lose their spring.

Think of your hair’s proteins like a Slinky toy. A new one stretches and recoils perfectly. A damaged one just pulls apart. I use this test in my clinic to pinpoint protein deficiency.

Over 80% of my clients with high breakage have poor elongation. They often overload on moisture but skip protein treatments. This imbalance makes hair stretchy but weak.

When Elongation Factor Fails from Heat Damage

Excessive heat unravels your hair’s disulfide bonds permanently. This destroys its natural elasticity. The hair may feel stretchy when wet but snaps easily.

I call this “overcooked spaghetti hair” in my practice. It has the limp, weak stretch of a noodle that’s been boiled too long. The structural integrity is gone.

Never combine high heat with chemical processes. I see the worst elongation failure in clients who bleach and flat iron regularly. The cumulative damage is irreversible.

The Humidity Test for Elongation Factor

Humidity directly impacts your hair’s stretch. Hair absorbs moisture from the air, which changes its elongation properties. This is why frizz happens.

Think of each strand like a tiny hygrometer. As it absorbs water, it swells and stretches. This is a sign of high porosity hair that loses its shape easily.

I advise clients with low elongation to avoid humectants in humid climates. Products with glycerin can make hair over-stretch and become mushy.

How Elongation Factor Changes with Hair Type

Different hair types have unique elongation factors. Coily hair has the highest natural stretch capacity. Straight hair has less inherent stretch but often more strength.

Think of it like different types of springs. A tight coil spring has more potential stretch than a slight wave. This is why Type 4c hair can shrink up to 70% but stretch significantly.

I never recommend the same products for all textures. High-elongation hair needs more protein to support its stretch. Low-elongation hair needs flexibility.

Will It Work For You?

✓ Yes

  • If your hair stretches slightly and returns to length without breaking
  • When you notice less breakage after protein treatments
  • If your wet hair feels strong and elastic, not mushy

✗ No

  • If your hair stretches very little and snaps immediately (brittle)
  • When hair stretches too much and doesn’t bounce back (over-processed)
  • If you have recent chemical damage or severe heat damage

From My Experience

The elongation test is my most reliable in-clinic tool. I have clients gently stretch a single wet hair strand. Healthy hair should stretch about 30% and return.

Hair that breaks immediately needs protein. Hair that over-stretches needs moisture balance. This simple test prevents more damage than any product.

I’ve developed a proprietary method combining this test with porosity checks. It accurately predicts how hair will react to coloring or straightening. This saves clients from disastrous results.

Celestine Gitau is a Certified Trichologist (International Association of Trichologists – IAT), Trichology tutor, and experienced hair and scalp health specialist. She has extensive expertise in diagnosing, treating, and managing hair loss across all hair types, with a focus on afro-textured hair. Over her career, she has been involved in more than 450 hair transplant procedures and hundreds of advanced treatments including PRP therapy, nutritional supplementation, and stem cell applications. As a dedicated educator and blogger, she has authored numerous in-depth articles to raise awareness on hair and scalp health. Her work combines clinical experience, ongoing research, and a passion for patient education.
Note: The information shared is for educational purposes only and is not a substitute for professional medical advice. Always consult a qualified healthcare provider for personalized guidance.