What Do Doctors Think About Finasteride?

October 7, 2025 •

5 min read

Affecting up to 50% of men by age 50, androgenetic alopecia is a common concern discussed in doctors' offices [1.9.1]. When considering treatments, what do doctors think about finasteride? The consensus is that it's a highly effective medication, but one that requires careful patient counseling.

Quick Summary

Doctors widely regard finasteride as an effective, first-line treatment for male pattern hair loss due to its proven ability to slow hair loss and promote regrowth. However, they also maintain a cautious stance, emphasizing the importance of discussing potential sexual, mental, and physical side effects with patients before prescribing it.

Key Points

High Efficacy: Doctors view finasteride as a very effective treatment for male pattern baldness, with studies showing it stops hair loss progression in up to 90% of men [1.2.4].
Mechanism of Action: It works by inhibiting the 5-alpha-reductase enzyme, significantly lowering levels of DHT, the hormone responsible for hair loss [1.4.5].
Side Effect Counseling: A critical part of prescribing is counseling patients on potential side effects, which include sexual dysfunction (ED, low libido) and mental health changes like depression [1.4.1, 1.10.3].
PFS Controversy: The existence of Post-Finasteride Syndrome (PFS), where side effects persist after stopping the drug, is a recognized but debated topic among medical professionals [1.5.1, 1.5.2].
Continuous Use Required: Doctors stress that finasteride's benefits are only sustained with continuous, long-term use; stopping the medication leads to a reversal of its effects [1.8.3].
Patient Screening: Responsible medical practice includes screening for a history of mental health conditions before prescribing, as this may increase risks [1.10.5].
Alternative Treatments: Doctors consider finasteride alongside other options like topical minoxidil and the more potent, off-label dutasteride [1.7.3, 1.7.5].

The Medical Consensus on Finasteride's Efficacy

Doctors, particularly dermatologists and hair restoration specialists, largely agree that finasteride is a cornerstone in the treatment of androgenetic alopecia (male pattern baldness) [1.9.1]. Originally developed to treat benign prostatic hyperplasia (BPH), its effectiveness in combating hair loss has been demonstrated in numerous long-term studies [1.2.1, 1.9.2]. The medication works by inhibiting the type II 5-alpha-reductase enzyme, which is responsible for converting testosterone into dihydrotestosterone (DHT) [1.4.5, 1.7.5]. DHT is the primary hormone that causes hair follicles to shrink and eventually stop producing hair [1.4.5]. By reducing scalp DHT levels by about 70%, finasteride can effectively halt the progression of hair loss and, in many cases, stimulate regrowth [1.9.1].

Long-term studies have validated its success. A 10-year study found that 86% of men taking finasteride experienced no worsening of their hair loss [1.2.1]. Another five-year study showed positive results in 65% of men with mild to moderate hair loss [1.2.2]. Many physicians view the medication as a success even if it only prevents further hair loss rather than producing significant regrowth [1.6.1]. For optimal results, doctors often combine finasteride with topical minoxidil, which works through a different mechanism to stimulate hair growth [1.2.1, 1.2.2]. It is crucial for doctors to communicate that treatment must be continuous; if a patient stops taking finasteride, the benefits are typically reversed within 12 months [1.8.3, 1.2.4].

A Doctor's Caution: Understanding the Side Effects

While doctors endorse finasteride for its efficacy, they also approach it with caution due to a range of potential side effects. The conversation between a doctor and patient before starting treatment is critical. The most commonly discussed adverse effects are sexual in nature, including erectile dysfunction (ED), decreased libido, and ejaculation issues [1.4.1]. These side effects are reported in a small percentage of users, typically between 1-4%, and often resolve after discontinuing the medication [1.2.3, 1.4.4]. Some studies even note that these effects can diminish over time even with continued use [1.4.4].

Beyond sexual side effects, there is growing awareness and discussion in the medical community about neuropsychiatric effects. The FDA has added warnings about depression and suicidal ideation to finasteride's label [1.10.3]. Studies have shown a disproportional signal for these psychological adverse events, particularly in younger men using the drug for alopecia [1.10.2]. The proposed mechanism involves finasteride's impact on neurosteroid levels in the brain, which can affect mood and cognition [1.5.2, 1.10.4]. Therefore, responsible prescribing involves screening patients for a history of mental health issues, as some studies suggest an increased risk of severe outcomes in those with pre-existing mood disorders [1.10.5].

Other less common side effects that doctors consider include gynecomastia (breast enlargement), orthostatic hypotension (dizziness upon standing), and potential impacts on fertility, although effects on sperm parameters from the 1 mg dose appear to be reversible upon cessation [1.4.1, 1.4.3].

The Controversy of Post-Finasteride Syndrome (PFS)

A significant part of the medical discussion revolves around Post-Finasteride Syndrome (PFS). PFS is a term used to describe a constellation of persistent sexual, neurological, and physical side effects that continue even after stopping the medication [1.4.1]. The existence and prevalence of PFS are highly debated within the medical community [1.5.3]. Some doctors and researchers believe it is a genuine clinical entity, with studies exploring potential mechanisms like altered neurosteroid levels, gut microbiota changes, and even epigenetic modifications [1.5.1, 1.6.2].

Conversely, other experts suggest the symptoms may be attributable to a 'nocebo' effect, where negative expectations about a treatment lead to adverse effects [1.5.2]. A study highlighted that men counseled on potential sexual side effects reported them at a much higher rate (46.3%) than those who were not (15.3%) [1.5.2]. A 2023 survey of dermatologists showed that while 51% believed finasteride could cause sexual side effects, only 18% believed those effects could be persistent [1.6.5]. This division underscores the controversy and the need for more research. Regardless of the debate, clinicians are encouraged to discuss the possibility of persistent side effects with their patients [1.5.2].

Prescribing Practices and Patient Counseling

When a patient presents with hair loss, a doctor's first step is to confirm the diagnosis of androgenetic alopecia. The standard prescribed dose for hair loss is a 1 mg oral tablet taken once daily [1.8.4]. This is distinct from the 5 mg dose used to treat BPH [1.8.1].

Responsible prescribing involves a thorough discussion of the following points:

Efficacy and Expectations: Explaining that the primary goal is to stop progression and that regrowth varies. Benefit is only maintained with continuous use [1.2.1, 1.8.3].
Potential Side Effects: A clear and balanced discussion about the risks, including sexual, mental, and physical side effects, is essential [1.4.4, 1.6.5].
PFS Controversy: Acknowledging the reports and debate surrounding persistent side effects allows for fully informed consent [1.5.1, 1.5.2].
Patient History: Screening for pre-existing conditions, especially depression or other mood disorders, is a crucial part of the risk assessment [1.10.3, 1.10.5].
Alternatives: Discussing other options, such as topical minoxidil, topical finasteride, dutasteride, or hair transplant surgery [1.4.5, 1.2.2].

Comparison of Hair Loss Treatments

Doctors often consider finasteride in the context of other available treatments. A comparison helps patients make an informed choice.


Feature	Oral Finasteride (1mg)	Oral Dutasteride (0.5mg)	Topical Minoxidil (5%)
Mechanism	Inhibits Type II 5-alpha-reductase, reducing DHT by ~70% [1.9.1, 1.7.5].	Inhibits Type I & II 5-alpha-reductase, reducing DHT by >90% [1.7.2, 1.7.5].	Vasodilator, increases blood flow to scalp and prolongs growth phase [1.7.5].
Efficacy	Highly effective at halting loss and promoting regrowth [1.2.4].	Considered more potent and potentially more effective than finasteride [1.7.3, 1.7.2].	Effective, especially for vertex; often used in combination with finasteride [1.2.1].
Administration	Once-daily oral pill [1.8.3].	Once-daily oral pill (often off-label for hair loss in the US) [1.7.3].	Twice-daily topical application to the scalp.
FDA Approval	Yes, for male pattern hair loss [1.7.5].	Not FDA-approved for hair loss in the US, but approved in other countries like Japan and South Korea [1.7.3].	Yes, available over-the-counter [1.4.5].
Side Effects	Low risk of systemic side effects, including sexual and mental health concerns [1.4.4].	Higher potential for side effects than finasteride due to greater DHT suppression [1.7.5].	Primarily local irritation, itching, or unwanted hair growth; low risk of systemic effects.

Conclusion

The medical community's view of finasteride is nuanced. It is widely recognized as a highly effective and generally safe first-line treatment for male pattern hair loss, backed by decades of clinical use and long-term studies [1.2.2, 1.9.2]. Doctors frequently prescribe it and see significant success in their patients [1.6.1]. However, this endorsement is balanced with a strong sense of caution. There is a clear consensus on the importance of transparent communication with patients about the potential for sexual and neuropsychiatric side effects, as well as the ongoing debate surrounding the persistence of these effects in the form of Post-Finasteride Syndrome [1.5.2, 1.6.5]. The decision to prescribe finasteride is ultimately a collaborative one, weighing the proven benefits against the potential risks for each individual patient.

Authoritative Link: For more detailed information on finasteride, visit the National Center for Biotechnology Information (NCBI) Bookshelf

Frequently Asked Questions

Yes, doctors generally consider finasteride safe for long-term use. Large-scale studies over 10 years have demonstrated its long-term safety and efficacy, with a low rate of adverse reactions [1.9.2, 1.2.3].

The standard and FDA-approved dose of finasteride for male pattern hair loss is one 1 mg tablet taken once daily [1.8.3, 1.8.4]. A higher 5 mg dose is prescribed for benign prostatic hyperplasia (BPH) [1.8.1].

This is a topic of debate. The concept of Post-Finasteride Syndrome (PFS) describes persistent side effects after discontinuation. While its existence is controversial, doctors are increasingly aware of these reports. A survey showed only 18% of dermatologists believe the sexual side effects are persistent, but they are encouraged to counsel patients on the possibility [1.6.5, 1.5.2].

Topical finasteride is seen as a promising alternative that may offer similar efficacy with lower systemic absorption, potentially reducing the risk of side effects [1.9.3]. However, doctors note it is less studied than the oral version and still carries risks. It is often prescribed off-label [1.6.3, 1.6.4].

Finasteride is strictly contraindicated for women who are or may become pregnant due to the risk of birth defects in a male fetus [1.4.1]. It is sometimes used off-label in postmenopausal women, though studies show it is not as effective as it is in men [1.8.1, 1.9.4].

Doctors recognize dutasteride as a more potent medication because it inhibits both type I and II 5-alpha-reductase, leading to a greater reduction in DHT compared to finasteride (which only inhibits type II) [1.7.2, 1.7.3]. While potentially more effective, it may also carry a higher risk of side effects and is not FDA-approved for hair loss in the US [1.7.5, 1.7.3].

According to clinical studies, a small percentage of men, typically between 1% and 4%, report adverse effects such as erectile dysfunction or decreased libido. The incidence of these effects is low [1.2.3, 1.4.1].