Sudden hair loss? This is usually telogen effluvium.

Telogen effluvium (TE)

Telogen effluvium (TE) is temporary hair loss. In this condition, many hairs stop growing too early and enter the resting phase of the hair growth cycle.

Under normal circumstances, 80–90% of your hairs are in the growth phase. Due to stress, more hairs shift into the resting phase. As a result, you notice hair shedding 6–12 weeks later.

Dr. Petra Dikrama (Erasmus MC Rotterdam) states that TE is the most common cause of sudden, diffuse hair loss in otherwise healthy individuals. With diffuse hair loss, hair is shed evenly across the entire scalp rather than in one specific area.¹

The Netherlands Society for Dermatology and Venereology (NVDV) confirms that this is a reversible form of hair loss: the hair roots remain intact and resume growth once the body has recovered. In telogen effluvium, the hair roots are therefore still healthy, but temporarily inactive.

In this blog, you can read more about other causes of sudden hair loss (other than telogen effluvium).

Hair loss caused by illness

An infection, high fever, surgery, or serious medical condition can abruptly halt the hair growth cycle. During illness, your body directs all its energy toward recovery, causing hair growth to temporarily stop. This explains why many patients experience hair loss after illness, hair loss after surgery, or hair loss after pregnancy.

• Hair loss after COVID-19, flu, or pneumonia: usually 2–3 months later.
• Hair loss after childbirth (postpartum TE): due to a drop in the hormone estrogen.
• Hair loss in Graves’ disease or other autoimmune disorders: the immune system disrupts the hair cycle or directly attacks the hair root.

In most cases, hair regrows within six months, once the underlying condition is under control.

Hair loss caused by stress

Prolonged psychological or physical stress has a direct effect on the hair follicle via the stress hormone cortisol.

During periods of stress, more hairs enter the resting phase, and hair shedding becomes noticeable after 6–12 weeks.

Frequently asked questions

Does hair loss caused by stress grow back?
Yes, almost always. Once stress levels decrease and the body recovers, the growth phase restarts.

How long does stress-related hair loss last?
On average 3–6 months; full recovery may take up to 1 year.

What can you do about hair loss caused by stress?
Restoring sleep, relaxation, physical activity, and proper nutrition helps normalize the hair cycle.

Telogen effluvium caused by stress occurs in both women and men. People often mistakenly assume this is hereditary hair loss (androgenetic alopecia).

Hair loss caused by blood thinners or other medications

Certain medications can trigger telogen effluvium. Examples include some blood thinners, beta blockers, antidepressants, and thyroid medication. Never stop medication on your own initiative — always consult your doctor first.

There are now blood thinners available that are less likely to cause this side effect compared to older medications.

Recognizing the signs of telogen effluvium

• Diffuse hair loss in women or men: evenly distributed across the entire scalp
• No bald patches, no scarring, no inflammation
• Usually starts 2–3 months after the trigger (illness, stress, medication)
• Sometimes mild scalp itching (telogen effluvium itch)

According to the NVDV, hair shedding usually stops within 3–6 months (up to a maximum of one year). After this, the hair density recovers with full regrowth of new hairs. Persistent shedding may indicate chronic telogen effluvium or contributing factors such as low ferritin (iron levels).

How long does telogen effluvium last – and will my hair grow back?

Many patients ask: “How long does telogen effluvium last?” On average 3–6 months, after which new hairs become visible; full recovery may take up to 12 months.

“The hair roots are not destroyed, only temporarily at rest. Patience is the most important medicine.”²

This applies to both hair loss caused by illness and stress: once the underlying trigger disappears, hair growth restarts.

Are there hair growth treatments that can help my hair grow back faster?

In the Netherlands, minoxidil (over-the-counter) and finasteride (prescription-only) are available. These are government-approved and proven treatments for hair loss. Minoxidil (foam or solution) is registered for androgenetic alopecia (hereditary hair loss).

Research shows that topical minoxidil can accelerate the transition from the resting phase to the growth phase, helping restore hair density more quickly. Another effect of minoxidil use is that hair may also become thicker.⁷

In this blog, you can read more about how minoxidil works in detail.

Other studies indicate that minoxidil, although developed for androgenetic alopecia, may also be effective in temporary hair loss after stress or illness.⁶ The well-known Cleveland Clinic in the United States confirms this:

“Minoxidil can accelerate the recovery of hair density after telogen effluvium when used consistently.”⁵

What can you do yourself when experiencing hair loss due to stress or illness?

Support your recovery

• Healthy nutrition: sufficient protein, iron (ferritin), zinc, and B vitamins (see the practical list below this article).
• Rest and sleep: stress lowers hair growth hormones and increases cortisol.
• Gentle hair care: you may dye your hair with telogen effluvium, provided mild products are used.
• Avoid overtreatment: only use supplements or lotions on medical advice.

When should you see a doctor?

• Hair shedding lasting longer than 6 months or the presence of clear bald patches
• Symptoms such as itching, pain, or scalp inflammation
• Fatigue or weight changes (possible thyroid disorder)

Nutrition and supplements

• Eat sufficient protein: fish, chicken, eggs, meat or meat substitutes; legumes; milk, yogurt, or quark; nuts or seeds.
• Ensure adequate iron and ferritin: red meat, chicken, liver sausage; whole grains; legumes, spinach, kale, broccoli; combine plant-based iron with vitamin C.
• Vitamins and hair growth: zinc and vitamins B6, B12, and biotin; eggs, milk, cheese; whole grain products; nuts; shellfish.
• Drink enough water: 1.5–2 liters per day to prevent dry hair or scalp.
• Supplements: only if a true deficiency is present; have blood tests done by your GP before taking additional vitamins or supplements.

Summary: what helps with telogen effluvium

Other causes and forms of sudden hair loss can be found in this blog.

references

1. Dikrama P. Hair loss in women: when is screening necessary? Family Doctor & Science, 2021.
2. Dikrama P. Diffuse hair loss due to telogen effluvium, Huisarts & Wetenschap, 2024.
3. NVDV – Telogen Effluvium . Dutch Society for Dermatology and Venereology, 2021.
4. Randall VA et al. Mechanisms of Action of Minoxidil in Hair Regrowth. J Am Acad Dermatol. 2020;82(6):1346–1354. PubMed PMID 32229253
5. Cleveland Clinic. Telogen Effluvium Overview., 2024 .
6. Perera F. et al. Treatment of Chronic Telogen Effluvium With Oral Minoxidil: A Retrospective Study. F1000Research. 2017;6:1650.
7. Ohyama M. et al. Use of 5% Topical Minoxidil Application for Telogen Effluvium: An Open-Label Single-Arm Clinical Trial. The Journal of Dermatology. 2025