Almost everyone wants hair to grow faster, whether they are growing out a cut or worried about thinning. The truth is that the speed at which each hair grows is largely set by genetics and is hard to change much. What you can influence is whether hair grows to its normal potential, and whether it breaks or sheds before it gets there. This guide separates what affects hair growth from the myths.
How fast hair grows
Scalp hair grows around a centimeter a month on average, though this varies from person to person and slows somewhat with age. Each follicle cycles through a growth phase that lasts years, a short transition phase and a resting phase before the hair sheds. How long your growth phase lasts largely determines how long your hair can get.
What can hold growth back
- Nutritional deficiencies. Low iron, low protein intake, and deficiencies in nutrients such as vitamin D or zinc have been linked with hair shedding. A doctor can check with blood tests. See iron deficiency and hair loss.
- Thyroid conditions. Both underactive and overactive thyroid can cause diffuse thinning.
- Stress, illness and rapid weight loss. These can push many hairs into the resting phase at once, causing shedding a few months later (telogen effluvium).
- Breakage. Heat styling, chemical treatments and tight hairstyles can break hair or damage follicles, so hair never seems to get longer.
- Scalp conditions. Inflammation, dandruff and other scalp problems can contribute to shedding and discomfort.
- Pattern hair loss. In androgenetic alopecia, follicles gradually shrink and produce thinner, shorter hairs.
What helps hair reach its potential
- Balanced nutrition with enough protein, iron and calories.
- Gentle hair care: less heat, fewer harsh chemical treatments, looser styles and a wide-tooth comb on wet hair.
- Treating underlying conditions such as thyroid problems or deficiencies, with a physician.
- A healthy scalp: addressing dandruff or irritation.
Common myths
- Trimming makes hair grow faster. It does not change the growth rate at the root, though it can reduce split ends and breakage.
- Supplements speed growth for everyone. Supplements are most likely to matter when there is a deficiency. High-dose biotin can also interfere with some lab tests, so tell your doctor if you take it.
- Special shampoos or oils speed growth. Most have limited evidence for changing the growth rate.
When thinning is the real issue
If your concern is thinning rather than length, the goal is different. Prescription treatments for pattern hair loss, such as minoxidil or finasteride, aim to slow loss and support density rather than make each hair grow faster, and they require a provider's review. Read about how to prevent hair loss.
See a physician in person for sudden or patchy hair loss, scalp pain or scarring, or hair loss with other new symptoms.
Next step
If you are concerned about thinning and want a licensed provider to review your situation, start your online consultation.
Prescription required for prescription treatment. A licensed provider decides whether treatment is appropriate. Compounded medications are prepared by a licensed pharmacy for an individual patient and are not FDA-approved. Individual results vary. Prescribed Essence currently serves patients in California, Colorado, Florida and New York.
