The Telogen Phase Explained: Understanding the Resting Stage of Hair Growth

When we look in the mirror, we often view our hair as a singular entity—a mane that is either having a good day or a bad day. However, the reality of hair biology is far more complex and dynamic. Every single strand on the human head is on its own individual journey, operating on a biological clock independent of its neighbors. While the majority of hair is actively growing, a significant portion is constantly in a state of hibernation known as the Telogen phase, or the resting phase. Understanding this phase is critical for anyone looking to improve hair density, reduce anxiety around shedding, and maintain optimal scalp health.

For clients visiting professional salons concerned about hair fall or lack of volume, the Telogen phase is often the most misunderstood part of the process. It is frequently villainized as the "shedding phase," but in reality, it is a necessary period of physiological rest that allows the hair follicle to rejuvenate and prepare for new regeneration. Without the Telogen phase, the cycle of renewal would collapse. By demystifying what happens during these dormant months, individuals can take better control of their hair care routines and recognize the difference between a healthy cycle and a condition requiring professional attention.

In this comprehensive guide, we will delve deep into the mechanics of the Telogen phase. We will explore its role within the broader hair growth cycle, distinguish it from active shedding, discuss the phenomenon of Telogen Effluvium, and provide actionable advice on how to care for hair that is currently "sleeping." Whether you are a hair enthusiast or simply looking to understand your own scalp better, this knowledge is the foundation of long-term hair wellness.

1. The Four Stages of the Hair Growth Cycle

To truly grasp the significance of the Telogen phase, one must first understand the ecosystem in which it operates. The hair growth cycle is a continuous loop of regeneration consisting of four distinct stages: Anagen, Catagen, Telogen, and Exogen. At any given moment, a healthy scalp has follicles in all four stages, though the ratios differ significantly. This asynchronous nature prevents humans from shedding their entire coat at once, unlike some mammals that molt seasonally. The balance between these phases is delicate and influenced by genetics, hormones, and overall health.

The Anagen Phase (Growing): This is the active phase where cells in the root of the hair are dividing rapidly, adding to the hair shaft. For scalp hair, this phase lasts anywhere from two to seven years. The longer the Anagen phase, the longer the hair can grow. Approximately 85% to 90% of the hair on a healthy head is in this phase at any given time. It is the phase most people associate with "healthy hair," but it cannot exist without the subsequent phases that allow the biological machinery to reset.

The Catagen Phase (Transition): Following the long growth period, the hair enters a short transitional stage known as Catagen. This lasts only about two to three weeks. During this time, hair growth stops, and the outer root sheath shrinks and attaches to the root of the hair. The hair is cut off from its blood supply and the cells that produce new hair. It forms what is known as a "club hair." This is the prelude to the resting phase, signaling to the body that the active work is done for now.

The Telogen Phase (Resting): This is the focus of our discussion. Lasting generally around three months (or approximately 100 days), the Telogen phase is a period of quiescence. The follicle is completely at rest. While the club hair remains anchored in the follicle, no new growth occurs. In a healthy scalp, roughly 10% to 15% of hairs are in this stage. It is a time of conservation and preparation beneath the surface, essential for the eventual re-emergence of new growth.

2. Deep Dive: What Happens During the Telogen Phase?

Physiologically, the Telogen phase is fascinating because it represents a state of biological suspension. During this time, the hair follicle is not dead; it is merely dormant. The hair shaft that was formed during the Anagen phase and disconnected during the Catagen phase is now fully keratinized and sits high up in the follicle. It is held in place by friction and the structure of the follicular wall. Because the hair is no longer attached to the papilla (the blood supply), it does not grow, change color, or repair itself. It is essentially a finished product waiting for its final exit.

Why does the body need this resting period? Cellular division—specifically the rapid division required to grow hair—is incredibly energy-intensive. The Anagen phase requires a constant, high-volume supply of nutrients and oxygen. The Telogen phase allows the cellular machinery of the follicle to reboot. Think of it as a factory shutting down for maintenance. The stem cells in the bulge area of the follicle remain viable, waiting for the chemical signals that will trigger the start of a new Anagen phase. If the body is under stress or lacking resources, it may prolong this rest or push more follicles into this state to conserve energy for vital organs.

During this phase, the hair is fully formed but arguably at its most vulnerable regarding retention. While it is anchored, it is not fused to the root system in the same way an Anagen hair is. This is why aggressive brushing or tight hairstyles can easily dislodge Telogen hairs. However, under normal circumstances, the club hair remains in place until the biological clock strikes, signaling the follicle to wake up. Understanding that the hair is biologically disconnected helps explain why nutritional changes today might not affect the look of the hair shaft instantly but will impact the next hair that grows after the Telogen phase ends.

3. Telogen vs. Exogen: The Distinction Between Resting and Shedding

For years, scientists and stylists alike lumped the shedding process into the Telogen phase. However, modern trichology (the study of hair and scalp) now recognizes a fourth distinct phase called Exogen. It is crucial to distinguish between Telogen (resting) and Exogen (shedding) to understand hair health. The Telogen phase is the state of the follicle holding the hair; Exogen is the active event of the hair falling out. The two are linked, but they are not the same event.

During the transition from Telogen to Anagen, the Exogen phase occurs. As the resting phase concludes, the follicle receives a signal to begin a new Anagen phase. A new hair shaft begins to form at the base of the follicle. As this new hair pushes upward, it eventually dislodges the old club hair (the Telogen hair), causing it to shed. This is why shedding is actually a sign of new growth in a healthy cycle. Losing 50 to 100 hairs a day is considered normal because that is roughly the number of follicles exiting the Telogen phase and entering Exogen daily.

Confusion arises when clients notice hair in their shower drain and assume their hair has stopped growing. In reality, the hair that falls out has been dead and resting for three months. The shedding event is the final step of a process that began weeks ago. Therefore, if a person experiences a sudden increase in shedding, the trigger for that event likely occurred three months prior, pushing those hairs into the Telogen phase prematurely. Recognizing this lag time is essential for diagnosing hair issues and managing expectations regarding treatments.

4. Telogen Effluvium: When the Resting Phase Goes Wrong

While the Telogen phase is a natural part of the cycle, it can become problematic when the balance is disturbed. The most common condition related to this phase is Telogen Effluvium (TE). This is a form of temporary hair loss characterized by excessive shedding. It occurs when a physiological or psychological stressor "shocks" the system, forcing a large percentage of Anagen (growing) hairs to prematurely enter the Telogen (resting) phase. Instead of the usual 10%, a person with TE might have 30% or even 50% of their hair shift into the resting phase simultaneously.

Because the Telogen phase lasts about three months, the shedding does not happen immediately after the stressor. A client might experience a high fever, a traumatic event, childbirth, or a crash diet in January, but the massive shedding won't appear until April. This delayed reaction often causes confusion and panic, as the individual cannot link the current hair loss to the past event. The shedding appears diffuse, meaning it happens all over the scalp rather than in patches, leading to a general thinning of the hair density.

Common triggers for Telogen Effluvium include severe illness, thyroid imbalances, rapid weight loss, iron deficiency, surgery, and significant emotional stress. The good news is that Telogen Effluvium is almost always reversible. Once the underlying trigger is resolved (e.g., stress is managed, diet is corrected, or the body recovers from illness), the follicles will naturally cycle back into the Anagen phase. However, because hair grows slowly (about half an inch per month), it can take six months to a year to regain previous density. Patience is key when recovering from a TE episode.

5. Nutritional Support for the Telogen Phase

Even though the hair shaft in the Telogen phase is not growing, the follicle itself is alive and preparing for its next task. Therefore, nutrition plays a pivotal role in determining how quickly and robustly the follicle re-enters the Anagen phase. If the body lacks essential nutrients, the follicle may remain in the resting phase longer than necessary, leading to increased thinning and a delay in new growth. A diet rich in specific vitamins and minerals is the best defense against prolonged dormancy.

Iron and Ferritin: Iron is critical for hair growth. Low iron stores (measured by ferritin levels) are a leading cause of chronic Telogen Effluvium, especially in women. The body considers hair a non-essential tissue; if iron is low, the body will divert it to vital organs like the heart and lungs, leaving hair follicles without the energy to leave the resting phase. Maintaining adequate iron levels through lean meats, spinach, lentils, or supplementation (under medical supervision) is vital.

Vitamin D: Emerging research suggests that Vitamin D plays a direct role in cycling the hair follicle. Receptors for Vitamin D are found in the follicle, and deficiency has been linked to hair loss. Ensuring adequate sun exposure or taking supplements can help "wake up" dormant follicles. Additionally, Protein and Amino Acids are the building blocks of keratin. Since the follicle is gearing up to build a new hair shaft, ensuring a high-protein diet prepares the body for strong Anagen production.

6. Scalp Care During the Resting Phase

How one treats the scalp during the Telogen phase can influence the retention of club hairs and the health of the emerging new hairs. Since Telogen hairs are anchored less securely than growing hairs, they require gentle handling. Aggressive styling, high-tension ponytails, and vigorous towel drying can prematurely pull out these resting hairs before the new growth is ready to replace them, leading to temporary thinness.

Gentle Cleansing and Exfoliation: A healthy scalp environment is crucial for the transition from resting to growing. Product buildup, sebum, and dead skin cells can clog the follicular opening, potentially hindering the emergence of new hair. Using a gentle, sulfate-free shampoo ensures the scalp remains clean without stripping natural oils. Periodic scalp exfoliation—using chemical exfoliants like salicylic acid or physical scrubs—can help keep the pathway clear for new Anagen hairs to break through the surface.

Stimulating Blood Flow: Blood circulation is the delivery system for the nutrients the follicle needs to restart growth. Scalp massage is an excellent technique to employ during the Telogen phase. By massaging the scalp for a few minutes daily, blood flow is increased to the follicles. This does not necessarily save the hair that is destined to shed, but it creates a fertile environment for the new hair that is forming underneath. Professional salons often offer specific scalp treatments designed to oxygenate the skin and stimulate microcirculation.

7. Professional Salon Treatments and the Telogen Phase

While home care is essential, professional salon services can significantly assist in managing the hair growth cycle. Stylists trained in trichology or scalp health can identify signs of excessive shedding or stagnation in the growth cycle. They can recommend treatments that bridge the gap between medical intervention and cosmetic beauty. It is important to view the stylist as a partner in hair health, not just someone who cuts and colors.

Scalp Facials and Detox Treatments: Many high-end salons now offer "scalp facials." These multi-step treatments involve deep cleansing to remove impurities, followed by massage to stimulate circulation, and the application of serums rich in peptides and growth factors. For hair in the Telogen phase, these treatments ensure that the resting environment is optimal. They can help reduce inflammation, which is known to negatively impact the hair cycle and potentially shorten the growth phase.

Low-Level Laser Therapy (LLLT): Some salons and clinics offer light therapy. LLLT uses specific wavelengths of light to penetrate the scalp and stimulate cellular activity in the follicle. Studies suggest that this therapy can help push follicles from the Telogen phase back into the Anagen phase more quickly. While often used for genetic hair loss, it can also be beneficial for general hair rejuvenation and keeping the cycle moving efficiently.

Tips for Managing Hair During the Resting Phase

• Monitor, Don't Obsess: It is normal to lose hair daily. If you notice a slight increase, monitor it for a few weeks before panicking. Stressing about hair loss can actually trigger more hair loss.

• Avoid High Tension: During periods where you suspect many hairs are in the resting phase (like post-pregnancy or post-illness), avoid tight braids, heavy extensions, or high ponytails that put traction on the roots.

• Upgrade Your Pillowcase: Switch to a silk or satin pillowcase. The reduced friction helps prevent Telogen hairs from being rubbed out prematurely during sleep.

• Cool Down the Water: Wash hair with lukewarm water rather than scalding hot water. excessive heat can dehydrate the scalp and stress the follicles.

• Brush with Care: Use a wide-tooth comb or a brush specifically designed for wet hair. Start from the ends and work your way up to avoid snapping fragile hairs or pulling out resting hairs unnecessarily.

Frequently Asked Questions (FAQ)

Q: Can I stop hair from entering the Telogen phase? A: No, the Telogen phase is a natural biological necessity. You cannot stop it, nor should you want to. The goal is to maintain a healthy ratio (about 10-15% resting) and prevent premature shifting of growing hairs into the resting phase due to stress or poor health.

Q: How do I know if my hair loss is normal shedding or Telogen Effluvium? A: Normal shedding is consistent and usually involves 50-100 hairs a day. Telogen Effluvium is characterized by a sudden, dramatic increase in shedding (often 300+ hairs a day) where handfuls may come out in the shower or brush. If you can see your scalp more visible than usual, it may be TE.

Q: Does coloring my hair affect the Telogen phase? A: Chemical processing affects the hair shaft, not the follicle underneath the skin, provided no chemical burns occur. However, if the scalp is irritated by harsh chemicals, inflammation could potentially disrupt the cycle. Always have chemicals applied by professionals who protect the scalp.

Q: How long does it take for hair to grow back after the Telogen phase? A: Once the old hair sheds (Exogen), the new hair (Anagen) is usually already just below the surface. However, because hair grows about 1/2 inch per month, it may take 3 to 6 months to see significant volume returning and short "baby hairs" popping up.

Q: Can supplements shorten the Telogen phase? A: While supplements cannot change your genetics, correcting deficiencies (like Iron, Vitamin D, or B12) can optimize the body's ability to switch back to the growing phase efficiently. A healthy body creates a healthy hair cycle.

Q: Is the Telogen phase the same for men and women? A: The biological mechanism is the same, but the duration of the Anagen (growing) phase varies. Women typically have longer Anagen phases than men. However, the Telogen phase remains consistently around 3 months for both sexes.

Conclusion

The Telogen phase is often the unsung hero of the hair growth cycle. While it is easy to focus on the active growth of the Anagen phase or the shedding of the Exogen phase, the resting period is where the follicle recuperates and prepares for the future. By understanding that rest is a vital part of renewal, individuals can approach hair care with a more holistic mindset. It is not just about growing hair faster; it is about supporting the hair through every season of its life.

Maintaining a healthy lifestyle, managing stress, and treating the scalp with the same care given to the face are the best ways to ensure the hair cycle runs smoothly. If shedding becomes excessive or prolonged, seeking advice from a professional stylist or a dermatologist is the best course of action. Remember, hair growth is a marathon, not a sprint, and the Telogen phase is simply the necessary pause that allows the race to continue.