It started with a few extra hairs: in my brush, on my bathroom floor, strewn across my pillow. Odd, but nothing too alarming, women shed hair all the time. But then there were more. They were dispersed across my computer at work and would fall into my hands at the slightest tug. I began to spiral: could others see them too? I swore I could feel each strand of hair popping off my scalp and drifting down my back.
After a few visits to the doctor, I had a name for it: telogen effluvium, a common condition characterized by diffuse hair shedding, often triggered by stress on the body. In my case, a high fever from a respiratory infection. Within no time, I was scouring the internet, craving a comprehensive understanding of the condition and what I could do to remedy the hair loss. I was met with various ‘health gurus’ pushing ‘miracle cures’, pricey supplements, and colourful shampoos – most of which were coupled with affiliate codes. Learning the science behind telogen effluvium brought me a sense of peace and clarity. By understanding its biology, I was able to question misinformation and avoid unnecessary emotional and financial strain.
Here’s what the research says about telogen effluvium and a few of its hot topic treatments: caffeine shampoo, biotin supplements and minoxidil.
What is telogen effluvium?
Telogen effluvium (TE) is a type of diffuse, non-scarring hair loss. This means shedding occurs all over the scalp without permanent damage to hair follicles, leaving the potential for complete regrowth. It typically presents as sudden, excessive shedding (often with hair falling in handfuls), as well as increased thinning and visibility of the scalp. Most cases are acute, with shedding lasting less than six months. However, in chronic cases, the condition can persist for years, with cycles of relapse and regrowth.
What is the scientific basis of telogen effluvium?
There are three principal phases of hair growth. First is the anagen phase, where hair grows actively for 3 to 6 years. Then comes catagen, a brief transition phase where growth stops, and the hair follicle begins to shrink. Next is the telogen phase, a resting phase that culminates in the exogen phase, during which the hair is shed. At any given time, approximately 15% of our hair is in the telogen phase, which is why losing 50–100 hairs a day is perfectly normal.
When the body undergoes significant stress—such as intense infections, major surgery, severe trauma, hypothyroidism, or nutritional deficiencies—up to 70% of hair follicles (the tiny structures in the skin that grow hair) can abruptly shift from the anagen phase to the telogen phase. As a result, the affected hairs sit dormant for one to six months and begin to fall out once the follicles finally re-enter the growth phase. This aligns with the evolutionary logic that hair growth, a non-essential function, is deprioritized when the body is under threat and explains the month(s) long delay between stressful events and hair loss. Animal studies also support this mechanism: in mice, exposure to stressors like loud noise can prematurely halt the anagen phase and induce hair loss.
TE is distinct from other common types of hair loss, such as Alopecia areata, an autoimmune disease that causes patches of hair loss, and Androgenetic alopecia, which is primarily driven by genetics but can be intensified by factors like hormones, stress, and diet.
Who is affected by TE?
TE can affect just about anyone. Although, its actual prevalence is unknown, as many cases go unreported. It’s more commonly observed in women, but this may be because women are more likely to notice changes in hair density and seek medical advice.
During the COVID-19 pandemic, TE received increased attention. One study found that nearly a quarter of patients recovering from the virus (48 out of 198) showed signs of TE a few months after infection.
Psychological Implications
While the TE is relatively benign, it’s widely recognized that the condition can have a dramatic psychological impact. It’s not shallow or trivial to acknowledge that hair holds deep cosmetic and personal significance and can seriously impact one’s confidence. Women suffering from the condition often report intense anxiety, disrupted sleep, and difficulty with day-to-day functioning. Unfortunately, this vulnerability is frequently exploited. The internet is flooded with expensive products promising quick fixes, many of which lack scientific backing.
Navigating TE treatments
During my initial wave of telogen effluvium panic, I filled up my shopping cart with countless influencers’ recommendations before stepping back and wondering which products aligned with the science behind TE. Here’s the science on some of the heaviest-marketed products:
Caffeine-rich shampoo: The principal mechanism of action behind these shampoos involves counteracting the effects of dihydrotestosterone (DHT). This hormone alters hair follicles, leading to hair loss in Androgenetic alopecia. Importantly, DHT is not a factor in telogen effluvium, which you may want to consider before splurging on a new shampoo.
Biotin: Biotin has a reputation that extends beyond the TE community and is widely associated with promoting nail and hair growth. However, products containing this vitamin are not likely to confer notable benefits after TE. Without a deficiency, there’s little evidence that biotin supplements or enriched products boost hair growth, and true biotin deficiencies are rare. One 2020 study, for example, found no significant difference in biotin levels between TE patients and healthy controls.
Topical minoxidil: Topical minoxidil is popular in the hair loss community. It works by widening blood vessels, allowing increased amounts of blood, nutrients and oxygen to reach the hair follicles, promoting hair growth. It also shortens the telogen phase, allowing hair follicles to re-enter the growth phase after the telogen hairs are shed. That being said, it does not prevent hair from exiting the growth phase, and there is no direct evidence that it speeds up recovery from TE in particular. In short, minoxidil does not counter the shedding of hairs that have already transitioned to the telogen phase but may bolster hair growth after shedding.
Telogen effluvium is typically self-limiting, meaning it resolves on its own over time without the need for treatment. It is important to be aware that once hair fibers enter the telogen phase, they cannot return to the growth stage, meaning no ‘strengthening and revitalizing shampoo’ will prevent the strands from falling once its follicle begins growing a new hair. That said, a nutrient-rich diet and effective stress management can support speedy regrowth and help slow the transition of additional hairs to the telogen phase. For more severe cases, there are also more advanced clinical interventions, such as platelet-rich plasma, botulinum toxin A, or multivitamin mesotherapy injections, which patients can discuss with their physicians.
In summary, most cases of TE resolve with time, and steps like managing stress and eating well can aid recovery. For more stubborn instances, advanced treatments exist, but we should be wary of one-size-fits-all “cures”, which often ignore the specific biology behind different hair loss conditions.
My outlook moving forward:
Researching telogen effluvium, I have found comfort in understanding the condition’s causes, its typical timeline, and what treatments are evidence-based (and what aren’t). While the specifics of my recovery remain uncertain, I’m focusing on building healthy habits, managing stress, and practicing self-compassion. If you’re going through something similar, I hope this knowledge helps you feel a little more in control, too.
Ana Sophia recently earned a Bachelor of Science in Neuroscience and Computer Science from McGill University. She will soon begin graduate studies in Health Data Science through the Population Health Sciences program at the University of Cambridge. Her research interests include Public Health, Psychiatry, and Computational Neuroscience.
