Hair growth is a repeating cycle of activity and rest within the hair follicle. Whether hair stops growing depends on distinguishing between temporary interruptions in this cycle and permanent destruction of the hair follicle itself. Most perceived hair “stopping” is a temporary state of dormancy, not a permanent cessation of biological function.
The Normal Hair Growth Cycle
The life of a hair follicle is divided into three distinct phases that occur asynchronously across the scalp, preventing all hair from shedding simultaneously. Hair growth begins with the Anagen phase, the active growth period that typically lasts between two and seven years for scalp hair. During this time, cells at the base of the follicle divide rapidly, forming the hair shaft.
The transitional phase, known as Catagen, follows and is relatively short, lasting only about two to three weeks. In this stage, the hair follicle shrinks, detaches from the blood supply, and growth stops. The follicle then enters the Telogen phase, the resting period lasting around three to four months.
During Telogen, the hair is inactive and waits to be naturally shed (losing 50 to 100 hairs daily is normal). A new Anagen hair begins to form beneath the resting hair, pushing the old hair out to restart the cycle. Approximately 85 to 90 percent of scalp hairs are actively growing in the Anagen phase at any given time.
Factors Causing Temporary Stalling
Temporary stalling of hair growth, often perceived as sudden hair loss, occurs when a significant percentage of hairs prematurely shift from the growing (Anagen) phase into the resting (Telogen) phase. This condition, known as Telogen Effluvium, is a reaction to a major physiological or psychological shock. Increased shedding typically becomes noticeable two to four months after the triggering event.
Common triggers that disrupt the normal hair cycle include severe emotional trauma, physical stressors (such as major surgery, acute illness, or high fever), and hormonal fluctuations (postpartum or thyroid disorders). Rapid weight loss, crash dieting, or specific nutritional deficiencies can also halt hair growth by depriving the follicles of necessary resources. Deficiencies in iron, zinc, and Vitamin D are frequently implicated.
Telogen Effluvium is generally reversible; the hair follicles remain intact and can resume normal growth once the underlying cause is corrected. The hair fall itself is often a sign of recovery, as the old, resting hair is pushed out by the new hair entering the Anagen growth phase.
When Hair Growth Stops Permanently
True and permanent cessation of hair growth occurs when the hair follicle structure is irreversibly damaged or permanently shrinks. The most common cause of permanent loss is Androgenetic Alopecia, or pattern baldness, which involves follicular miniaturization. In genetically susceptible individuals, the hormone dihydrotestosterone (DHT) causes the hair follicle’s Anagen phase to progressively shorten with each cycle.
This shortened growth window prevents the hair from reaching its full potential, causing the hair to become progressively finer and shorter until it resembles vellus hair, or “peach fuzz,” and eventually disappears. The follicle itself has not died, but its ability to produce a thick, visible hair shaft has been functionally shut down.
A more destructive cause is Scarring Alopecia, also called cicatricial alopecia, where inflammation directly targets and destroys the stem cells within the hair follicle. Conditions like Lichen Planopilaris and Central Centrifugal Cicatricial Alopecia cause the follicle to be replaced by scar tissue, which is incapable of regenerating hair. The key distinction from temporary stalling is that this follicular destruction means the hair cannot regrow in the affected area.
Options for Stimulating Growth
Addressing hair growth stalling or loss begins with an evaluation to determine if the cause is temporary or permanent. For temporary stalling due to Telogen Effluvium, the most direct stimulation involves managing the underlying trigger, such as resolving a nutritional deficiency or reducing emotional stress. Adopting a balanced diet rich in iron, zinc, and protein is a foundational step to ensure follicles have the necessary building blocks for healthy hair production.
For both temporary thinning and pattern hair loss, the over-the-counter medication Minoxidil is a well-established option. Minoxidil works by increasing blood flow to the scalp, which prolongs the Anagen phase and encourages resting follicles to re-enter the growth cycle. Available in 2% and 5% topical solutions or foams, consistent daily application is necessary, with visible results typically taking at least four months.
Certain supplements, particularly the B-vitamin Biotin, may provide support for hair health. While high-dose supplementation is often unnecessary without a deficiency, it can be used alongside Minoxidil. Low-level laser therapy (LLLT) is another non-invasive option that uses specific wavelengths of light to stimulate cellular activity within the hair follicles, promoting growth and reducing the progression of miniaturization.