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How Long Does Finasteride Take to Work?

Knox Beasley, MD

Reviewed by Knox Beasley, MD

Written by Vanessa Gibbs

Published 09/17/2017

Updated 01/18/2024

Finasteride (generic Propecia®) is a prescription medication that can stop hair loss in its tracks and help with new hair growth.

But how long does finasteride take to work? Like most meds, it doesn’t work instantly. It can take three to four months for finasteride to work, and you may notice the most improvements after a year of use. 

Below, we’ll dive into how long it takes for finasteride to work and how the drug works exactly. We’ll also go over a few techniques you can use to boost results and get a fuller head of hair.

It takes about three or four months for finasteride to work on your hair. 

Finasteride will start working as soon as it’s absorbed by your body. But it can take a while for the drug to build up in your system and produce any noticeable changes up top. 

Hair growth is a slow process, so it could be a few months or even a full year before you notice real improvements in your hairline.

As with any treatment, everyone responds differently. So it’s hard to say for sure how long it’ll be until finasteride works for you.

It’s worth hanging in there and being patient with finasteride, though. The drug has been shown to slow hair loss and promote partial hair regrowth in about two-thirds of men.

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It may take three to four months to see hair growth from finasteride. The longer you take finasteride tablets, the more benefits you’ll see.

You might notice an increase in terminal hair (thick hair like those on your head) and a decrease in vellus hair — those fine baby hairs you get all over your body. 

Finasteride can lead to vertex hair growth (hair growth on the crown of your head) and superior-frontal scalp hair growth — hair regrowth around a receding hairline and on the top of the head.

But, word of warning: Finasteride isn’t guaranteed to help regrow hair you’ve already lost. It may just slow down or stop male pattern hair loss from progressing any further. 

Although, if you’re concerned about hair loss, slowing or stopping future hair loss will probably still feel like a big win.

You may see final improvements from finasteride after a year of treatment. 

Studies show finasteride reaches peak efficacy in one year, and it works to slow the progression of hair loss with continued treatment. 

If you don’t notice any changes in your hairline at first, don’t give up. You should use finasteride for a year before deciding whether to continue treatment. 

And if it does work for you, it’s not a one-and-done treatment. You should take finasteride daily, indefinitely, to keep up the hair-boosting benefits. If you stop taking finasteride, the benefits may reverse within a year.

Check out our guide to the finasteride results timeline for insight into what you can expect to see in your hair month by month.

Finasteride is a hair loss treatment approved by the FDA (U.S. Food and Drug Administration) to treat androgenic alopecia in men (male pattern hair loss) and benign prostatic hyperplasia (BHP, or enlarged prostate). 

Finasteride belongs to a class of medications called 5-alpha-reductase inhibitors (5ARIs). As the name suggests, 5ARIs inhibit the enzyme 5-alpha-reductase. 

This enzyme is responsible for the conversion of testosterone into dihydrotestosterone (DHT), a male sex hormone linked to hair loss. 

DHT isn’t all bad, though. Before birth, it plays a role in the development of male genitalia. And during puberty, it promotes facial hair and body hair growth.

It’s during adulthood that DHT becomes rather annoying. The hormone can cause prostate enlargement and male pattern baldness in those predisposed to the condition. 

When it comes to hair loss, DHT binds to receptors in the scalp and causes hair follicle miniaturization. This means it shortens the anagen phase (or growth phase) of the hair growth cycle.

Miniaturization leads to thinner and shorter hair follicles and, eventually, hair so short it doesn’t reach the surface of the scalp. Yikes. Learn more in our full guide to DHT and its role in male pattern baldness

This is when finasteride enters the chat.

Finasteride reduces how much DHT is in your system. It’s pretty powerful — the medication can decrease prostate DHT levels by upwards of 90 percent and blood DHT levels by 70 percent. This helps slow hair loss. 

A 2019 study looked at how effective a daily 1-milligram finasteride treatment was in 532 men. Participants were followed for 10 years, and the results were pretty impressive. 

The oral finasteride treatment led to an improvement in male pattern hair loss for 91.5 percent of the men and prevention of further hair loss for 99.1 percent. We like those odds.

And there’s more good news. No serious adverse reactions were recognized across the entire decade of treatment.

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Finasteride starts working immediately in your body. It gets to work reducing DHT levels straight away.

But, unfortunately, you won’t notice improvements in hair loss immediately. It can take three or four months — or even a year — to start seeing a reduction in hair loss and any hair regrowth.

Minoxidil is a topical hair loss treatment option. It’s available over the counter in a foam or liquid solution. This medication is FDA-approved to treat male pattern hair loss and female pattern baldness, and it’s used off-label for other types of hair loss. 

It’s unclear how minoxidil works exactly. But we know it shortens the telogen phase (also known as the resting phase) and extends the anagen phase (the growth phase) of the hair growth cycle. This leads to longer, thicker hair. 

Why are we talking about minoxidil all of a sudden? Well, finasteride and minoxidil make a great team.

A 2019 systematic review and meta-analysis looked at five randomized controlled trials of finasteride and minoxidil. The results showed that using finasteride and minoxidil together was more effective than using one of the treatments alone.

The finasteride-minoxidil combo led to more patients with a marked improvement in hair loss and fewer patients with deterioration or no change in hair loss compared to using just one of the treatments.

But, unfortunately, minoxidil isn’t a quick fix, either. It can take about eight weeks for minoxidil to start producing benefits for your hair, and it may take four months to see the maximum effects.

Consider adding our minoxidil foam and minoxidil liquid solution to your hair care routine.

Yes, finasteride can cause side effects.

The most common side effects of oral finasteride include: 

Most men who take finasteride won’t experience any side effects, though. 

Clinical trials found that 1.8 percent of men who took finasteride experienced decreased libido compared to 1.3 percent of those who took a placebo.

If you’re concerned about potential side effects, consider topical finasteride instead of the oral medication. The topical treatment can come with fewer adverse effects. Learn more in our guide to topical finasteride side effects

Still, more research is needed to determine how effective topical finasteride is. 

Some studies show it can reduce DHT but doesn’t help with hair growth. Other studies show that topical finasteride is as effective as oral finasteride after 18 months of treatment.

Side effects of finasteride are rare, but they can happen. If you notice any adverse reactions, including sexual side effects, reach out to a healthcare provider to get medical advice and discuss the best course of action.

Want to slow and reverse hair loss, stat? Here’s how to make the most of finasteride to stop hair loss and boost hair growth: 

  • Don’t miss a daily dose. The treatment works best when you take a 1-milligram dose of finasteride daily. Set a reminder and make it a habit. You’ll only delay when finasteride starts working if you keep missing doses.

  • Use minoxidil and finasteride together. As noted, research shows that using both minoxidil and finasteride can be more effective than using just one treatment alone. Check out our topical finasteride & minoxidil spray as one option.

  • Switch to hair-friendly products. Give your hair the best chance of looking thick and healthy by using a volumizing shampoo, volumizing conditioner or thickening shampoo with saw palmetto.

  • Eat a balanced, healthy diet. Research shows that vitamins and minerals play an essential role in hair follicle development — guess Mom was right when she said you should eat your veggies. Check out our guide to the best foods for hair growth to see what you should be adding to your grocery list to promote a healthy head of hair.

  • Try hair supplements. Our biotin gummies contain folic acid, plus vitamins B7, B12, C, D and E (to name just a few) to support healthier hair. 

  • Lower your stress levels. We know it’s much easier said than done, but try not to stress too much — about hair loss or life in general. Stress can cause telogen effluvium, a type of hair loss that leads to hair shedding. So get out in nature, call a friend, and make time to unwind to keep your stress low and hair count high.

  • Take progress photos. Hair growth is a sloooowwww process. It can help to take progress photos when you’re on finasteride to compare how your hair loss and growth are going over time.

We’ve covered more lifestyle changes you can make in the fight against hair loss.

Hair loss treatments, delivered

So, how long does it take finasteride to work? If you’re beginning to lose your hair, you can expect to see some improvements from finasteride after three to four months of use, with more significant results visible after approximately one year. 

Here’s what you need to know about the hair loss medication: 

  • Finasteride can slow male pattern hair loss. Studies show that it’s an effective treatment to slow hair loss. It may boost hair thickness, length and regrowth too.

  • It takes a while to kick in. You might start noticing improvements after three or four months, but hang in there for a full year to really see what finasteride can do. And remember, you need to keep taking finasteride to keep seeing the benefits.  

  • Finasteride can come with side effects. These include lowered libido, ejaculation disorder and erectile dysfunction. Reach out to a healthcare provider if you experience any of these side effects (or anything else). 

Sold on finasteride? Connect with a licensed healthcare provider to get finasteride online through our telehealth platform. 

And if you’re looking for a hair loss treatment that doesn’t hold back, check out our Hair Power Pack. It contains everything you need — including oral finasteride, minoxidil drops, thickening shampoo and biotin gummies.

11 Sources

  1. Highlights of Prescribing Information. (n.d.).
  2. Ho, C. H., Sood, T., Zito, P. M. (2022, October 16). Androgenetic Alopecia - StatPearls. NCBI.
  3. Zito, P. M., Bistas, K. G., Syed, K. (2022, August 25). Finasteride - StatPearls. NCBI.
  4. Asfour, L., Cranwell, W., Sinclair, R. (2023, January 25). Male Androgenetic Alopecia.
  5. Shapiro, J., & Kaufman, K. D. (2003). Use of finasteride in the treatment of men with androgenetic alopecia (male pattern hair loss). The journal of investigative dermatology. Symposium proceedings, 8(1), 20–23.
  6. Kinter, K. J., Amraei, R., Anekar, A. A. (2023, July 30). Biochemistry, Dihydrotestosterone - StatPearls. NCBI.
  7. Yanagisawa, M., Fujimaki, H., Takeda, A., Nemoto, M., Sugimoto, T., & Sato, A. (2019). Long-term (10-year) efficacy of finasteride in 523 Japanese men with androgenetic alopecia. Clinical Research and Trials.
  8. Patel, P., Nessel, T. A., Kumar, D. D. (2023, November 15). Minoxidil - StatPearls. NCBI.
  9. Chen, L., Zhang, J., Wang, L., Wang, H., & Chen, B. (2020). The Efficacy and Safety of Finasteride Combined with Topical Minoxidil for Androgenetic Alopecia: A Systematic Review and Meta-analysis. Aesthetic plastic surgery, 44(3), 962–970.
  10. Almohanna, H. M., Ahmed, A. A., Tsatalis, J. P., & Tosti, A. (2019). The Role of Vitamins and Minerals in Hair Loss: A Review. Dermatology and therapy, 9(1), 51–70.
  11. Malkud S. (2015). Telogen Effluvium: A Review. Journal of clinical and diagnostic research : JCDR, 9(9), WE01–WE3.
Editorial Standards

Hims & Hers has strict sourcing guidelines to ensure our content is accurate and current. We rely on peer-reviewed studies, academic research institutions, and medical associations. We strive to use primary sources and refrain from using tertiary references. See a mistake? Let us know at [email protected]!

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. Learn more about our editorial standards here.

Knox Beasley, MD

Dr. Knox Beasley is a board certified dermatologist specializing in hair loss. He completed his undergraduate studies at the United States Military Academy at West Point, NY, and subsequently attended medical school at Tulane University School of Medicine in New Orleans, LA. 

Dr. Beasley first began doing telemedicine during his dermatology residency in 2013 with the military, helping to diagnose dermatologic conditions in soldiers all over the world. 

Dr. Beasley is board certified by the American Board of Dermatology, and is a Fellow of the American Academy of Dermatology.

Originally from Nashville, TN, Dr. Beasley currently lives in North Carolina and enjoys spending time outdoors (with sunscreen of course) with his wife and two children in his spare time. 





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