How Long Can Finasteride Keep Your Hair? A Guide to Long-Term Efficacy

October 7, 2025 •

4 min read

Affecting up to 85% of men by age 50, androgenetic alopecia is a common concern [1.8.2]. For those seeking treatment, a key question is: how long can finasteride keep your hair? This medication is a long-term commitment for sustained results [1.2.1].

Quick Summary

Finasteride is effective at slowing hair loss and maintaining hair for as long as it is taken continuously. Studies show high efficacy for 5 to 10 years, though benefits reverse upon discontinuation.

Key Points

Lifelong Commitment: Finasteride's effectiveness at keeping hair relies on continuous, long-term daily use; benefits reverse upon discontinuation [1.2.1].
High Long-Term Success: Studies show that over 90% of men maintain or improve their hair count over 5 to 10 years of use [1.2.4, 1.3.3].
Mechanism of Action: It works by inhibiting the enzyme 5-alpha-reductase, reducing scalp DHT levels by approximately 70% to stop follicle miniaturization [1.2.1].
Timeline for Results: Initial improvements may be seen in 3-6 months, with more noticeable results appearing around the 12-month mark [1.4.1].
Stopping Reverses Gains: If you stop taking finasteride, hair loss typically resumes, and any hair gained is usually lost within one year [1.5.1].
Side Effects Are a Factor: Potential side effects, though rare, include sexual dysfunction and mood changes, which should be discussed with a doctor [1.7.1].
Early Treatment is Better: Efficacy is generally greater for those who start treatment at a younger age and in the earlier stages of hair loss [1.3.3].

Understanding Finasteride and Male Pattern Baldness

Male pattern baldness, or androgenetic alopecia (AGA), is responsible for over 95% of hair loss in men [1.8.2]. The condition is linked to genetics and the hormone dihydrotestosterone (DHT) [1.2.4]. Testosterone is converted into DHT by an enzyme called 5-alpha-reductase [1.9.2]. In genetically predisposed individuals, DHT binds to receptors in the scalp and causes hair follicles to shrink, a process known as miniaturization. This shortens the hair's growth phase (anagen phase), leading to thinner, shorter hairs and eventual hair loss [1.4.1, 1.2.4].

Finasteride is a 5-alpha-reductase inhibitor. It works by blocking this enzyme, specifically the Type II isoenzyme, which prevents testosterone from converting into DHT [1.9.1, 1.9.3]. A daily 1 mg dose of finasteride can lower DHT levels in the scalp and serum by about 70%, which is enough to significantly slow, stop, and in some cases, reverse the miniaturization process [1.2.1, 1.2.4].

The Finasteride Results Timeline

Finasteride's effects aren't immediate and require patience and consistency. While the medication starts reducing DHT levels within 24 hours of the first dose, visible changes to your hair take several months due to the natural hair growth cycle [1.4.1].

Months 1-3: The Foundation Phase

During the first few months, you are unlikely to see noticeable improvements. The medication is working internally to lower DHT and protect your follicles, but it's too early for new, healthier hairs to have grown to a visible length. Some users may even experience a temporary shedding phase as thinner hairs are pushed out to make way for new growth [1.4.4, 1.4.5]. It is crucial to continue taking the medication daily during this period [1.4.1].

Months 3-6: Initial Improvements

Between three and six months, initial results often become apparent. You may notice that your hair loss has slowed down or stopped completely. Some regrowth, particularly at the crown (vertex) and mid-scalp, might become visible [1.4.1, 1.4.4]. One study noted significant improvement in men after just 12 weeks of use [1.4.1].

Month 12 and Beyond: Noticeable and Sustained Results

After one year of consistent daily use, the results of finasteride should be much more noticeable. Studies show significant increases in hair count and thickness [1.4.1]. About 83% of men with vertex hair loss using finasteride showed no further hair loss after two years [1.2.3].

Long-term studies confirm its sustained effectiveness. A 5-year study found that 90% of men taking finasteride experienced either improvement (48%) or no further hair loss (42%) [1.2.4]. A 10-year study in Japan involving over 500 men found that 91.5% showed improvement, with effectiveness being higher in men younger than 40 and those in earlier stages of hair loss [1.3.3, 1.3.5]. The key takeaway is that finasteride is a long-term treatment. It works as long as you take it [1.4.2].

Comparison Table: Finasteride vs. Other Hair Loss Treatments


Feature	Finasteride (Propecia)	Minoxidil (Rogaine)	Dutasteride (Avodart)
Mechanism	Oral 5-alpha reductase (Type II) inhibitor, reduces scalp DHT [1.9.1, 1.9.3].	Topical vasodilator, increases blood flow to follicles and widens them [1.7.2, 1.4.1].	Oral 5-alpha reductase (Type I & II) inhibitor, more potent DHT suppression [1.6.3, 1.6.5].
Application	Once-daily oral pill (1 mg for hair loss) [1.10.1, 1.10.2].	Topical solution or foam applied to the scalp, typically twice daily [1.4.5].	Once-daily oral pill (0.5 mg), off-label for hair loss in many regions [1.6.1, 1.6.3].
Efficacy	Highly effective; halts progression in ~90% of men over 5 years [1.2.4].	Less effective than finasteride for halting progression, but effective for regrowth [1.6.4]. Combination therapy is synergistic [1.4.1].	Considered the most effective of the three, with greater DHT suppression (~98%) and hair count increase [1.6.3, 1.6.5].
Side Effects	Rare but include sexual side effects (decreased libido, erectile dysfunction) in a small percentage of users [1.7.1, 1.7.2].	Scalp irritation, unwanted facial hair growth (hypertrichosis) [1.6.4].	Similar side effect profile to finasteride but may be more frequent due to higher potency [1.6.4, 1.6.5].

What Happens if You Stop Taking Finasteride?

The benefits of finasteride are not permanent and depend on continuous use [1.2.1]. If you stop taking the medication, your body's DHT levels will return to their previous baseline within about two weeks [1.5.4]. Consequently, the hair loss process will resume. Most men find that any hair they maintained or regrew due to the treatment will be lost within 9 to 12 months of stopping [1.5.1, 1.5.2]. Starting and stopping the medication is not recommended, as you will likely lose ground compared to continuous use [1.2.4].

Potential Side Effects and Considerations

While generally well-tolerated, finasteride can cause side effects. The most discussed are sexual in nature, including decreased libido, erectile dysfunction (ED), and issues with ejaculation [1.7.1]. Clinical trials show these affect a small percentage of users (e.g., 1.4% to 1.9%) [1.2.4, 1.7.4]. For many, these side effects decrease with continued use or resolve after stopping the drug [1.2.4]. However, there are reports of persistent side effects after discontinuation, a condition sometimes referred to as Post-Finasteride Syndrome (PFS), though its true incidence is unknown [1.5.3, 1.5.5].

Other potential side effects include breast tenderness or enlargement (gynecomastia), testicular pain, and mood changes like depression [1.7.1, 1.7.3]. It's crucial to discuss your medical history and any concerns with a healthcare provider before starting treatment.

An Important Note for Women

Finasteride is not FDA-approved for hair loss in women and is contraindicated for those who are or may become pregnant [1.11.1, 1.11.2]. It can cause severe birth defects in a male fetus. Women should not handle broken or crushed finasteride tablets [1.7.3].

Conclusion

Finasteride is a clinically proven, effective long-term treatment for male pattern baldness that can preserve hair for many years—as long as it is taken consistently. Studies demonstrate its ability to halt hair loss progression and promote regrowth in a vast majority of men, with some studies showing high efficacy even after a decade of use [1.3.3]. The decision to take finasteride should be made in consultation with a doctor, after weighing the significant, sustained benefits against the potential for side effects. For those who commit to the treatment, it remains one of the most powerful tools available in the fight against hair loss.

For further reading on the efficacy and safety of topical finasteride solutions, one alternative to the oral pill, you can review this study published by the National Institutes of Health: Efficacy and safety of topical finasteride spray solution for male androgenetic alopecia [1.2.5].

Frequently Asked Questions

While finasteride begins lowering DHT levels almost immediately, visible results such as slowed hair loss or initial regrowth typically take 3 to 6 months of consistent daily use. More significant results are often seen after 12 months [1.4.1].

No, finasteride is not a permanent cure. It is a long-term treatment that is effective only while you are taking it. If you stop, your hair loss will likely resume and return to its pre-treatment state within a year [1.5.1, 1.2.1].

The standard, FDA-approved dosage of finasteride for treating male pattern hair loss (androgenetic alopecia) is a 1 mg oral tablet taken once per day [1.10.1, 1.10.2].

Finasteride is not FDA-approved for women and is strictly contraindicated for women who are pregnant or may become pregnant due to the risk of causing birth defects in a male fetus. It is sometimes prescribed off-label for postmenopausal women [1.11.1, 1.11.2].

If you miss a dose, you should take it as soon as you remember, unless it's more than 6 hours late. In that case, skip the missed dose and resume your normal schedule. Do not take a double dose to make up for a missed one [1.10.2].

While some users may feel its efficacy wanes after many years, long-term studies of up to 10 years show that a very high percentage of men continue to benefit by either maintaining their hair or preventing further loss compared to not taking it. It continues to be effective as long as it is taken [1.3.3, 1.4.2].

Yes, combining oral finasteride with topical minoxidil is a common and effective strategy. Studies have shown that using both treatments together can have a synergistic effect and may be more effective than using either one alone [1.4.1, 1.6.4].