Whether a COVID-19 infection causes hair loss has been a frequent concern since the start of the pandemic. Scientific evidence confirms that a significant illness like COVID-19 is a recognized trigger for temporary hair shedding, a condition medically known as alopecia. This reaction is not unique to SARS-CoV-2, but the number of people affected brought this symptom into the public spotlight. This temporary phenomenon is a consequence of the severe physical and emotional stress the body endures during and after the viral infection.
The Primary Type of Hair Loss Observed
The most common form of hair loss reported after a COVID-19 infection is Telogen Effluvium (TE), a temporary condition characterized by excessive hair shedding. Hair growth follows a cycle with three main phases: the anagen (growing) phase, the catagen (transition) phase, and the telogen (resting/shedding) phase. Normally, approximately 85 to 90 percent of the hair on the scalp is in the growing phase, with only about 10 percent in the resting phase before it naturally sheds.
A severe physical stressor, like a high fever or viral infection, can prematurely shock a larger proportion of growing hairs into the resting phase. In cases of TE, up to 50 percent of the hair follicles may shift into the telogen phase, leading to noticeable, diffuse thinning across the entire scalp. This condition is non-scarring, meaning the hair follicles are not damaged, which is why it is almost always temporary.
Biological Triggers of Post-COVID Hair Shedding
The widespread shedding seen in Telogen Effluvium is a direct consequence of the body’s reaction to the acute COVID-19 infection. High fever is a well-established physical stressor that signals hair follicles to prematurely stop the growth cycle and enter the resting phase. Beyond fever, the body experiences severe systemic stress as it fights the virus, which diverts resources away from non-essential functions like hair production.
A significant biological trigger is the intense inflammatory response known as a “cytokine storm,” characteristic of moderate to severe COVID-19 cases. Inflammatory molecules like Interleukin-6 (IL-6) are elevated during the infection and disrupt the normal hair cycle. This massive surge of inflammation effectively puts hair growth on hold, leading to a large number of follicles entering the telogen phase. Psychological stress and anxiety resulting from the illness also contribute to the physical toll on the body.
Certain medications, such as antivirals or antibiotics prescribed during the illness, may also contribute to shedding. Furthermore, the body’s need to repair and recover following the viral attack takes precedence over hair production. This complex interplay of fever, inflammation, and emotional strain collectively forces the hair follicles into a synchronized resting state. The intensity of the initial COVID-19 infection, including the presence of respiratory symptoms, has been linked to a higher likelihood of subsequent hair loss.
Prognosis and Timeline for Recovery
The hair loss typically begins approximately two to four months after recovering from acute COVID-19 symptoms. This delay occurs because the hair follicle must complete the two-to-four-month resting phase before shedding. Some studies have noted an even earlier onset, with shedding starting around 50 to 74 days after the initial infection.
Once the shedding phase begins, it commonly lasts for three to six months, with patients noticing large amounts of hair falling out while showering or brushing. Telogen Effluvium is a self-limiting condition, meaning the excessive shedding will stop once the body stabilizes and the hair cycle resets. Regrowth is the standard outcome, as the hair follicles remain intact and ready to produce new hair.
While shedding typically resolves within six months, full hair density recovery may take up to 18 months. If the shedding persists beyond six to nine months, or if the hair loss appears in distinct, patchy areas, a consultation with a dermatologist is recommended. Prolonged or atypical hair loss suggests the possibility of underlying nutritional deficiencies or the unmasking of a pre-existing condition.
Managing and Treating Hair Loss
Since post-COVID Telogen Effluvium is temporary, management involves supportive care and patience while the hair cycle naturally corrects itself. Maintaining a diet rich in vitamins and minerals is important, as deficiencies in iron, vitamin D, and biotin can impede healthy hair growth. Gentle hair care practices can also help minimize further trauma to the stressed follicles.
This includes avoiding tight hairstyles, reducing heat styling, and using mild shampoos and conditioners. Managing stress and anxiety through practices like mindfulness or exercise supports the nervous system. Topical over-the-counter treatments like minoxidil can be used to stimulate hair follicles and accelerate regrowth. Consulting with a healthcare provider or a dermatologist is advised to confirm the diagnosis and rule out other potential causes of hair loss.