From the Guidelines
Female hair loss with normal thyroid function can be caused by several factors, including nutritional deficiencies, particularly iron, zinc, vitamin D, and B vitamins, as well as autoimmune conditions like alopecia areata, and hormonal changes. The most common cause is female pattern hair loss (androgenetic alopecia), which affects about 40% of women and is influenced by genetics and hormones, particularly dihydrotestosterone (DHT) 1. Other significant causes include telogen effluvium (stress-induced shedding), certain medications (including antidepressants, blood thinners, and chemotherapy drugs), and physical trauma to hair follicles from tight hairstyles or heat styling.
Key Causes of Female Hair Loss
- Nutritional deficiencies: iron, zinc, vitamin D, and B vitamins 1
- Autoimmune conditions: alopecia areata
- Hormonal changes: pregnancy, menopause, or stopping birth control pills
- Physical trauma: tight hairstyles or heat styling
Importance of Nutritional Deficiencies
Nutritional deficiencies, especially iron, have been linked to hair loss in females, with some studies suggesting that iron deficiency may be an initiating factor for alopecia areata 1. However, the evidence is not conclusive, and more research is needed to fully understand the relationship between iron deficiency and hair loss.
Treatment Options
Treatment options depend on the specific cause and may include:
- Topical minoxidil (typically 2% or 5% applied twice daily)
- Oral medications like spironolactone (50-200 mg daily) or finasteride (in select cases)
- Nutritional supplements to address deficiencies
- Platelet-rich plasma injections
- Low-level laser therapy It is essential to identify the underlying cause of hair loss through a thorough medical evaluation, which may include blood tests to check hormone levels, nutritional status, and inflammatory markers.
From the Research
Causes of Hair Loss in Females with Normal Thyroid Function
- Polycystic ovary syndrome (PCOS) is a common endocrine disorder that can cause hair loss in females, even with normal thyroid function 2, 3
- PCOS is characterized by hyperandrogenism, insulin resistance, and ovarian dysfunction, which can lead to hair loss, among other symptoms 4, 5
- Androgen excess, a key feature of PCOS, can cause hair loss, particularly androgenic alopecia 3, 6
- Insulin resistance and metabolic disturbances associated with PCOS can also contribute to hair loss 4, 6
- Other factors, such as obesity, acne, and hirsutism, can also affect self-esteem and contribute to hair loss in females with PCOS 3