Does Biotin Help Hair Growth? The Evidence Explained

Biotin supplements improve hair growth only in people with actual biotin deficiency, which is rare in developed countries, while the vast majority of people taking biotin for hair loss see no benefit because their biotin levels are already adequate. Understanding this distinction saves money and redirects effort toward treatments that actually work.

Biotin (vitamin B7) is one of the most heavily marketed supplements for hair, skin, and nails. Walk through any pharmacy and you'll find dozens of biotin products promising thicker, healthier hair. But what does the science actually say?

What is Biotin?

Biotin is a B-vitamin (B7) essential for:

• Converting food to energy (metabolism)

• Supporting healthy skin, hair, and nails

• Nervous system function

• Embryonic development during pregnancy

Your body needs biotin, but the amounts required are small, and it's found in many common foods.

Food sources of biotin:

• Eggs (especially yolks)

• Nuts and seeds

• Meat and fish

• Sweet potatoes

• Spinach

• Broccoli

• Whole grains

Most people eating a varied diet get sufficient biotin without trying.

The Biotin-Hair Connection: What's Real

Fact: Biotin deficiency causes hair loss

When someone is truly biotin deficient, they experience:

• Hair thinning and loss

• Brittle nails

• Scaly skin rash

• Neurological symptoms

In these cases, biotin supplementation genuinely helps, and hair improves.

Fact: Biotin deficiency is rare

In developed countries with adequate food supply, biotin deficiency is uncommon. It typically occurs with:

• Certain genetic disorders

• Long-term antibiotic use

• Excessive raw egg white consumption (biotin binding)

• Certain medications

• Severe malnutrition

• Pregnancy (increased requirements)

The average person eating normally is not biotin deficient.

The Problem: Supplementation doesn't help adequate levels

Here's where marketing diverges from science. If your biotin levels are already sufficient (as they are for most people), taking more biotin doesn't improve hair growth. Your body simply excretes the excess.

Analogy: If your car has a full tank of petrol, adding more doesn't make it run better. It just spills over.

What the Research Says

Studies on Biotin for Hair Loss:

Most studies showing biotin benefits hair involved people with demonstrated deficiency. Studies on people with normal biotin levels show minimal to no benefit.

A 2017 review in the journal Skin Appendage Disorders examined all published studies on biotin for hair and nails. The conclusion: "Evidence for the efficacy of biotin supplementation for healthy individuals is limited."

The marketing reality:

Many biotin supplement testimonials come from people who:

• Had undiagnosed deficiency (the supplement helped)

• Experienced placebo effect

• Attributed natural hair cycling to the supplement

• Also made other changes (diet, stress reduction)

Without controlled studies, these anecdotes don't prove cause and effect.

When biotin genuinely helps:

If you have one of the risk factors for deficiency, supplementation makes sense. Otherwise, you're likely spending money on expensive urine.

Why Biotin Won't Fix Male Pattern Baldness

Male pattern baldness (androgenetic alopecia) is caused by DHT affecting genetically susceptible hair follicles. This is a hormonal and genetic issue.

Biotin doesn't:

• Block DHT production

• Reduce DHT sensitivity

• Address the underlying cause

• Regenerate miniaturised follicles

Taking biotin for male pattern baldness is like putting vitamins in your car's fuel tank to fix an engine problem. It's the wrong intervention for the issue.

What actually addresses male pattern baldness:

• Finasteride (blocks DHT)

• PRP (regenerates follicles)

• Minoxidil (supports growth)

Explore evidence-based hair loss treatments

When Biotin Supplementation Makes Sense

Consider biotin if you have:

Risk factors for deficiency:

• Pregnancy or breastfeeding

• Long-term antibiotic use

• Certain medications (anti-seizure drugs)

• Inflammatory bowel disease

• Strict dietary restrictions

• Excessive alcohol use

Symptoms of deficiency:

• Hair thinning throughout (not pattern baldness)

• Brittle, splitting nails

• Scaly rash around eyes, nose, mouth

• Fatigue

• Numbness/tingling

If you suspect deficiency, blood testing can confirm before supplementing.

The Problem with High-Dose Biotin

Many hair supplements contain 5,000-10,000 mcg of biotin when the daily requirement is only 30 mcg. This creates two issues:

1. Wasted money

Excess biotin is excreted in urine. You're literally flushing money away.

2. Lab test interference

High-dose biotin can interfere with certain blood tests including:

• Thyroid function tests (falsely abnormal results)

• Cardiac troponin (heart attack marker)

• Hormone tests

This can lead to misdiagnosis or missed diagnosis of serious conditions. Always tell your doctor if you're taking biotin before blood tests.

What Actually Helps Hair Growth

Instead of wasting money on biotin you probably don't need, focus on interventions with evidence:

For Male Pattern Baldness:

1. Finasteride: Blocks DHT, stops progression in 90%

2. PRP: Regenerates follicles with growth factors

3. Minoxidil: Supports growth through different mechanism

For Nutritional Hair Loss:

If hair loss is related to deficiencies (common in women, vegetarians, those with absorption issues):

1. Iron: Most common deficiency affecting hair

2. Vitamin D: Affects follicle cycling

3. Zinc: Important for hair structure

4. Protein: Hair is made of protein

The smart approach: Get tested, identify actual deficiencies, supplement specifically what you lack, then consider regenerative treatments if pattern hair loss is present.

How to Know If You're Deficient

Blood testing can assess:

• Biotin levels (if suspected deficiency)

• Iron and ferritin

• Vitamin D

• Zinc

• Thyroid function

• Hormones

At The Wellness, our hair loss blood panel checks the nutrients that actually affect hair, giving you actionable information rather than guesswork.

The Bottom Line on Biotin

If you have deficiency: Biotin supplementation helps

If you have normal levels: Biotin supplementation is unlikely to help hair growth

If you have male pattern baldness: Biotin doesn't address the cause; you need DHT-targeting treatments

Before supplementing:

• Get tested if you suspect deficiency

• Save money on megadose supplements you don't need

• Invest in treatments that actually address your type of hair loss

Frequently Asked Questions

Should I stop taking biotin?

If you're taking it without confirmed deficiency, it's probably not helping your hair. The main risks are wasted money and potential lab test interference. If you want to continue, low-dose (within 100% daily value) is reasonable.

Do biotin shampoos work?

No. Biotin doesn't absorb through the scalp in meaningful amounts. This is pure marketing.

How long should I try biotin before expecting results?

If you have genuine deficiency, improvement can occur within 3-6 months. If you have normal levels, no amount of time will produce results.

Are there any side effects?

Biotin is generally safe, but high doses can cause acne in some people and interfere with lab tests.

What supplements DO help hair?

Only supplements addressing actual deficiencies help. The most common hair-affecting deficiencies are iron, vitamin D, and zinc. Get tested rather than guessing.

Get Proper Hair Loss Assessment

Stop guessing about supplements. Get tested, identify actual issues, and pursue treatments that work for your specific situation.

Discover what's really causing your hair loss. Book a consultation via WhatsApp

Medically reviewed February 2026

Last updated: February 2026