The Wait is Over: Understanding How Long it Takes for Finasteride to Work
Hair Loss

The Wait is Over: Understanding How Long it Takes for Finasteride to Work

Finasteride blocks DHT at the hair follicle to treat male-pattern baldness.

Also called androgenic alopecia, male-pattern (and female-pattern) baldness affects about 50 million men and 30 million women in the United States.1 Male-pattern baldness affects about half of men over age 50. It causes hair thinning, receding hairline, and balding.

Androgenetic alopecia is a common form of hair loss that is treatable and may even be reversible.

How do I know if finasteride is working?

Finasteride is a competitive inhibitor of Type II 5α-reductase, an enzyme that converts testosterone to dihydrotestosterone (DHT). Finasteride can reduce this enzyme’s activity.It reduces the amount of circulating DHT by about two-thirds and slightly increases testosterone levels. 2

DHT plays a key role in developing male genitalia, secondary sex characteristics, and facial and body hair growth. DHT receptors are found throughout the body, including hair follicles and the prostate.

Signs that finasteride is working include:

  • Reduced hair loss: This is one of the first signs that finasteride is working. You may notice less hair falling out, especially when you wash or brush your hair.
  • Regrowth of hair: Besides slowing hair loss, finasteride also promotes regrowth. You may notice new hairs growing in areas of the scalp that have been thinning or balding.
  • Thicker, fuller hair: As regrowth continues, your hair will be visibly thicker and fuller.

Finasteride works for people who have a genetic sensitivity to DHT. It does not work for everyone. Hair regrowth is expected in up of two-thirds of men with mild-to-moderate hair loss, and it stops future hair loss in about 91% of men.3

In two clinical trials, 1,553 men between the ages of 18 and 41 received oral finasteride or placebo for one year, and 1,215 men continued treatment for a second year. The men experienced increased hair count, slower hair loss, increased hair growth, and improved hair appearance.4

If you do not see signs of decreased hair loss and increased hair growth after several months of use, contact your doctor to discuss other options.

Single Man with Hair Loss Issue

How long does it take for finasteride to regrow hair?

Finasteride starts working as soon as you take it, but it takes a while to have a noticeable effect on your hair growth. It usually takes at least three months to see the effects of finasteride, and it may take a full year to see its full benefits. This seems like a long time, but the growth phase for hair can be as long as six years.

When is hair loss normal?

Everyone sheds about 50 to 100 hairs each day. There are three phases of hair growth:

  • Anagen (growth phase) can last for several years.
  • Catagen (transitional phase) lasts for about ten days.
  • Telogen (resting phase) typically lasts for two to three months.

You will notice more hair loss when too many hairs shift out of the growth phase and into the resting phase. DHT sensitivity shortens the hair follicle growth phase from years to weeks or months, and the hair follicles also decrease in size. With a shorter growth phase, more hairs enter the resting phase and fall out. A smaller hair follicle results in hairs that are thinner and less coarse.

When is it too late for finasteride?

Finasteride works best when it is started at the first sign of hair loss. However, you can benefit from finasteride, no matter what your age. If your hair loss is more advanced, your doctor may recommend combining two or more treatments that approach hair loss differently.

Finasteride requires a prescription. Like all medications, it has side effects, so it is important to talk with a doctor to determine whether it is the best hair regrowth option for you. If you have questions about finasteride, contact one of the treatment specialists at Invigor Medical.

Looking to buy finasteride online? See how Invigor Medical can help you today!


While we strive to always provide accurate, current, and safe advice in all of our articles and guides, it’s important to stress that they are no substitute for medical advice from a doctor or healthcare provider.  You should always consult a practicing professional who can diagnose your specific case.  The content we’ve included in this guide is merely meant to be informational and does not constitute medical advice.


  1. Genetics Home Reference, National Library of Medicine. (2020) Androgenetic alopecia.
  2. Gormley GJ, Stoner E, Rittmaster RS, et al. (1990). Effects of finasteride (MK-906), a 5α-reductase inhibitor, on circulating androgens in male volunteers. J Clin Endocrinol Metab;70:1136-1141
  3. Gormley GJ, Stoner E, Rittmaster RS, et al. (1990). Effects of finasteride (MK-906), a 5α-reductase inhibitor, on circulating androgens in male volunteers. J Clin Endocrinol Metab;70:1136-1141
  4. Kaufman KD, Olsen EA, Whiting D, et al. Finasteride in the treatment of men with androgenetic alopecia. Finasteride Male Pattern Hair Loss Study Group. J Am Acad Dermatol. Oct 1998;39(4 Pt 1):578-89. doi:10.1016/s0190-9622(98)70007-6
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Published: Mar 27, 2023


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