Finding hair in your brush is normal. Here’s how to tell when shedding is more than usual, and what nutrition can and can’t do.
The gist
- According to the American Academy of Dermatology, it’s normal to shed 50 to 100 hairs a day.
- Excessive shedding, called telogen effluvium, can follow stressful events such as illness, surgery, childbirth or major weight loss.
- Shedding often starts a couple of months after the trigger and usually improves once the cause has passed.
- The FDA has warned that biotin supplements can interfere with some lab tests.
Seeing hair in your brush or shower drain can be worrying, but some shedding every day is completely normal.
How much shedding is normal?
According to the American Academy of Dermatology (AAD), it’s normal to shed between 50 and 100 hairs a day. When the body sheds significantly more than that, the medical term is telogen effluvium.
Common triggers of excess shedding
| Trigger | Examples |
|---|---|
| Physical stress | An illness with a high fever, surgery, recovering from an infection |
| Hormonal changes | Giving birth, stopping birth control pills |
| Diet | Rapid weight loss, very restrictive diets |
| Emotional stress | A difficult life event |
Excess shedding often begins two to three months after the trigger. Once the cause has passed, hair usually returns to its normal fullness over the following months. The AAD notes, for example, that most new mothers find their hair is back to normal by their child’s first birthday.
Where nutrition fits in
Hair needs enough protein, calories, vitamins and minerals to grow. Very low-calorie or restrictive diets and deficiencies, such as low iron, can contribute to shedding. A varied diet with enough protein supports healthy hair, but if you already eat well, extra supplements are unlikely to make a difference. Our guide to diet and skin looks at similar claims about food and appearance.
Safety note
The FDA has warned that biotin, often sold in hair, skin and nail supplements, can interfere with some lab tests, including a test used to help diagnose heart attacks, and cause falsely low or high results. Tell your doctor about any supplements you take before a blood test.
Gentle hair care helps
- Use a wide-tooth comb on wet hair, and avoid pulling.
- Limit tight hairstyles that pull on your scalp.
- Turn down the heat on hair dryers and styling tools.
Beauty tip
Clean your hairbrush regularly and watch for a trend over a few weeks. A pattern over time tells you more than a single day’s count.
When to get it checked
See a doctor or dermatologist if shedding continues for more than a few months, you notice patches of hair loss or a widening part, or you have other symptoms such as unusual tiredness. A blood test can check for causes such as low iron or thyroid problems.
You asked
Will biotin make my hair grow faster?
Biotin deficiency is uncommon, and there’s little evidence that biotin supplements help people who aren’t deficient. Tell your doctor if you take biotin, because it can affect lab tests.
Can low iron cause hair loss?
Iron deficiency is one possible cause of hair shedding. A doctor can check your levels with a blood test; don’t take iron supplements without advice.
When should I see a doctor?
See a doctor or dermatologist if shedding lasts more than a few months, you notice bald patches, or your hair loss comes with other symptoms.
This article is general information, not medical advice. For skin, hair or nail problems that worry you, or before starting a new treatment if you’re pregnant, breastfeeding or have a health condition, talk to a board-certified dermatologist or your doctor.
