Does Levothyroxine Cause Hair Loss? Effects, Prevention & Treatment

Levothyroxine Hair Loss Treatment begins with understanding that levothyroxine is a synthetic thyroid hormone widely prescribed for hypothyroidism, a condition where the thyroid gland fails to produce enough hormones. While this medication is essential for managing thyroid health, it may raise concerns regarding side effects, including hair loss. In this comprehensive guide, supported by expert insight from an intermediary organization like Istanbul Care, we explore the causes, preventive strategies, and treatments for levothyroxine-related hair loss.

About Levothyroxine

Levothyroxine replaces or supplements the natural thyroid hormone thyroxine (T4). It regulates metabolism, energy levels, and overall hormonal balance. Available under brand names such as Synthroid, Euthyrox, and Eltroxin, it is a lifelong treatment for many.

Understanding the Hair Growth Cycle

Hair grows cycle in three distinct phases:

• Anagen phase (growth): Lasts 2–7 years
• Catagen phase (transition): Lasts 2–3 weeks
• Telogen phase (resting/shedding): Lasts about 3 months

Disruption in this cycle due to hormonal imbalances can push hair into the telogen phase prematurely, causing increased shedding.

Table: Hair Growth Cycle Overview

How Does Hypothyroidism Cause Hair Loss?

Hypothyroidism affects metabolism and protein synthesis, impairing hair follicle activity. Key impacts include:

• Dry, brittle hair
• Thinning, especially at the crown and eyebrows
• Slower regrowth
• Loss of hair volume
• Disruption of scalp circulation

Who Can and Cannot Take Levothyroxine

Levothyroxine is prescribed to patients with:

• Hypothyroidism
• Post-thyroidectomy hormonal maintenance
• Thyroid cancer treatment follow-up

Contraindications:

• Untreated adrenal insufficiency
• Recent heart attack
• Known hypersensitivity to levothyroxine
• Overactive thyroid conditions without medical supervision

How and When to Take Levothyroxine

Dosage and Strength

Initial dosage depends on:

• Age
• Weight
• Severity of hypothyroidism
• Cardiac risk

Typical doses range from 25 mcg to 150 mcg per day, and adjustments are based on regular blood tests.

How to Take Levothyroxine

• Take on an empty stomach, ideally 30–60 minutes before breakfast
• Avoid taking it with calcium, iron, antacids, or soy-containing foods
• Swallow tablets with water only (no coffee or milk)
• Be consistent with timing every day

If You Take Too Much

Overdose symptoms include:

• Palpitations
• Anxiety
• Sweating
• Weight loss
• Hair loss
• Irritability
• Heat sensitivity

If You Forget to Take It

• Take the missed dose as soon as you remember, unless it’s near the next dose time
• Do not double up doses
• Consult your healthcare provider if multiple doses are missed

Hair Loss Due to Levothyroxine Overdose

Anagen Effluvium and Levothyroxine

Excess hormone levels can force hair follicles into the shedding phase. This results in anagen effluvium, a sudden and severe form of hair loss seen in overdosed individuals.

Mechanism of Hair Loss in Thyroid Disorders

• Imbalance in thyroid hormones affects follicular cycling
• Increase in cortisol and inflammatory markers accelerates shedding
• Disruption of scalp oxygen and nutrient delivery

Levothyroxine Brand Name: Eltroxin

Eltroxin is one of many levothyroxine brands. Some patients may experience fewer side effects by switching brands due to filler ingredients or formulation differences. Consultation with an intermediary organization helps identify the best brand for your response.

Do Thyroid Hormones Affect Hair Growth?

Yes. Adequate thyroid hormone levels are essential for:

• Anagen phase duration
• Keratinocyte proliferation
• Hair follicle vascularization
• Healthy production of scalp sebum

How to Stop Hair Loss While on Levothyroxine

1. Keep Thyroid Hormone Levels in the Recommended Range

• Regular TSH, T3, and T4 monitoring
• Adhere strictly to prescribed doses

2. Consider Taking Supplements That Promote Hair Growth

• Biotin
• Zinc
• Vitamin D3
• Selenium
• Omega-3 fatty acids
• Iron (if deficient)

What Does Thyroid Hair Loss Look Like?

• Diffuse thinning across the scalp
• Loss of eyebrow tails (outer third)
• Thinning crown and temple areas
• Dry, lackluster strands
• Hair that breaks easily

Shouldn’t Levothyroxine Treat Hair Loss?

Yes, in patients with hypothyroidism-induced hair loss. However, if hair loss persists or worsens after starting treatment, it could be due to:

• Incorrect dosage
• Brand sensitivity
• Nutrient deficiencies
• Stress or autoimmune co-factors

How to Slow or Reverse Hair Loss

1. Eat a Well-Balanced Diet

• Rich in proteins, iron, omega-3s, and antioxidants
• Include spinach, eggs, nuts, and fatty fish

2. Limit Harsh Styling Practices

• Avoid tight hairstyles, chemical treatments, and excessive heat
• Use wide-toothed combs
• Air dry hair when possible

3. Treat Any Underlying Scalp Infections

• Use antifungal shampoos if needed
• Consult dermatologists if symptoms persist
• Consider topical steroids under prescription

Pregnancy and Breastfeeding

Levothyroxine and Pregnancy

• Safe and essential for fetal neurodevelopment
• Dose often needs to be increased to meet increased demands

Levothyroxine and Breastfeeding

• Safe during lactation
• Minimal secretion in breast milk
• Does not affect infant thyroid levels

How Can I Control My Hair Fall Due to Thyroid?

• Stay consistent with medication
• Manage stress levels with yoga or breathing exercises
• Use gentle, sulfate-free shampoos
• Regular scalp massages to improve blood flow
• Maintain hydration and sleep schedule

More Common Levothyroxine Side Effects May Include: