Best Supplements for Hair Growth

Separating proven support from expensive biotin hype

The hair supplement market is full of pretty packaging and weak evidence. Biotin is everywhere, but it only helps if you're actually deficient (most people aren't). Real hair support starts with ruling out deficiencies and addressing root causes.

Address Deficiencies First

Iron10/10
Effective Dose18-45mg daily if deficient
Time to Effect3-6 months (hair growth is slow)

Iron deficiency is one of the most common causes of hair loss, especially in women. Your hair follicles are sensitive to iron levels even before you're technically anemic. Get ferritin tested. Should be at least 50-70 ng/mL for optimal hair growth.

Best for:Women with heavy periodsVegetariansAnyone with low ferritin
Zinc10/10
Effective Dose15-30mg daily
Time to Effect3-6 months

Zinc is critical for hair tissue growth and repair. It keeps the oil glands around follicles working properly. Deficiency causes hair loss. But too much zinc is also a problem and can actually cause hair loss. Balance matters.

Best for:Those with zinc deficiencyVegetariansHeavy exercisers
Effective Dose2000-5000 IU daily
Time to Effect3-6 months

Low vitamin D is linked to alopecia. Hair follicles have vitamin D receptors. Many people are deficient, especially in winter or with limited sun exposure. Worth testing and correcting.

Best for:Those with low vitamin DLimited sun exposure

Additional Support

Effective Dose5-15g daily
Time to Effect3-6 months

Collagen provides amino acids (especially proline) that hair is made from. A few studies show improvements in hair thickness. Not magic, but reasonable support. Marine collagen may be slightly better absorbed.

Best for:General hair supportAlso benefits skin and nails
Biotin7/10
Effective Dose2.5-5mg daily
Time to Effect3-6 months if deficient

Here's the truth about biotin: it only helps if you're actually deficient. Most people get plenty from food. True deficiency is rare. The marketing has far outpaced the science here.

Best for:Actual biotin deficiencyThose on certain medications
Effective Dose320mg daily
Time to Effect3-6 months

May block DHT, the hormone behind pattern baldness. Limited but promising research for hair. Works differently than deficiency supplements. Might help with hormone-related hair loss.

Best for:Androgenetic alopeciaDHT-related hair loss

Beyond Supplements

  • Hair loss has many causes: hormones, stress, thyroid issues, autoimmune conditions
  • Get blood work done. Test iron/ferritin, vitamin D, thyroid, zinc.
  • Protein intake matters. Hair is made of protein.
  • Chronic stress triggers telogen effluvium (temporary shedding)
  • Most hair supplements need 3-6 months to show results. Hair grows slowly.

Note: Sudden or patchy hair loss should be evaluated by a dermatologist. These supplements support growth but don't treat medical conditions.

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