Dr. Thomas Dwan - Is It Bad For You? Approved by Dr. Thomas Dwan

Is Finasteride Bad For You?

Also Known As: Propecia, Proscar



Short answer

Finasteride is FDA-approved for treating male pattern hair loss and benign prostatic hyperplasia. Its benefits in reducing hair loss and prostate size are well-documented, however, it can cause side effects like sexual dysfunction, mood alterations, and, rarely, high-grade prostate cancer. Women, especially those of childbearing potential, should not use it. Long-term effects are variable and individual risk assessment is necessary. Alternative treatments exist and should be considered based on individual needs and side effects.



Long answer

Understanding Finasteride: Uses and Mechanism of Action

Finasteride is a medication primarily used to treat male pattern hair loss and benign prostatic hyperplasia (BPH), a condition in men characterized by an enlarged prostate gland. It belongs to a class of drugs known as 5-alpha-reductase inhibitors.

Uses of Finasteride:

  • Male Pattern Hair Loss: Marketed under names such as Propecia, finasteride treats androgenetic alopecia by preventing the conversion of testosterone to dihydrotestosterone (DHT), which is implicated in the thinning of hair and receding hairlines in men.
  • Benign Prostatic Hyperplasia: In higher doses, finasteride is used under the brand name Proscar. By decreasing DHT levels, it helps reduce prostate size, alleviate symptoms of BPH such as difficulty in beginning the flow of urine, and may lower the chance of the need for surgery related to an enlarged prostate.

Mechanism of Action:

  • Enzyme Inhibition: Finasteride works by inhibiting the enzyme 5-alpha-reductase. This enzyme converts testosterone into DHT, a hormone that can contribute to hair loss in men and the enlargement of the prostate.
  • Reduction of DHT Levels: By inhibiting 5-alpha-reductase, finasteride significantly lowers DHT levels in the scalp and the prostate. This decrease in DHT is responsible for its therapeutic effects in treating both conditions.

It is crucial to understand that while the reduction of DHT has therapeutic benefits, it is also responsible for potential side effects associated with finasteride use. Clinical studies have shown that finasteride is effective at stopping hair loss progression and improving BPH symptoms. A notable study published in the New England Journal of Medicine demonstrated the efficacy of finasteride in shrinking the prostate and improving symptoms over a period of several years.

Underpinning its use, the U.S. Food and Drug Administration (FDA) has approved finasteride for both BPH and androgenetic alopecia, backing its effectiveness when used as directed. The proper use of finasteride involves a clear understanding of its mechanism and having realistic expectations regarding the onset of its benefits, which may take a few months to become apparent.

As with all medications, consultations with healthcare professionals are essential to assess individual suitability for the drug, understand dosage instructions, and be aware of potential interactions and side effects, some of which may be long-lasting. This is particularly pertinent owing to the ongoing discourse surrounding finasteride's safety profile.

Common Side Effects of Finasteride Use

Finasteride, a medication primarily used to treat symptoms associated with benign prostatic hyperplasia (BPH) and male pattern baldness, is generally well-tolerated by many individuals. However, like all medications, it can have side effects. The common side effects of finasteride are diverse and can affect individuals differently depending on a variety of factors like dosage, duration of use, and individual sensitivity. It is important to discuss any concerns with a healthcare provider before starting treatment.

The following list includes some of the more commonly reported side effects of finasteride:

  • Sexual Side Effects: A percentage of patients report sexual dysfunction, which may include decreased libido, erectile dysfunction, and ejaculation disorders. Studies vary in their findings, but a review of clinical trials suggests these effects occur in 2.1-3.8% of men taking finasteride.
  • Psychological Effects: While less common, some individuals report experiencing mood changes, including symptoms of depression or anxiety. The relationship between finasteride and mood alterations is an area of ongoing research.
  • Physical Effects: Some men may experience tenderness or enlargement of the breasts, a condition known as gynecomastia.
  • Prostate-Specific Antigen (PSA) Levels: Finasteride can cause a decrease in PSA levels in the blood, which may influence prostate cancer screening results.

A 2019 review published in the journal Andrology reports that while these side effects are generally reversible, they may persist for some individuals after discontinuation of the drug, a phenomenon referred to as post-finasteride syndrome. However, the existence and causation of post-finasteride syndrome are still under scientific debate and require further investigation.

It is vital for users to be aware that the occurrence of side effects may be dose-dependent, and lowering the dose may decrease the incidence or severity of side effects, though this should always be done under medical supervision.

For those considering finasteride therapy, it is essential to balance the potential benefits of the drug against the likelihood and severity of side effects, in consultation with a healthcare provider. Rigorous clinical trials and post-marketing surveillance continue to monitor the safety profile of finasteride, providing patients and healthcare providers with the most current information for decision-making.

The Link Between Finasteride and Sexual Dysfunction

Finasteride, originally developed to treat benign prostate enlargement and later approved for male pattern baldness, has been associated with the risk of sexual dysfunction, a concern for many patients and healthcare providers. As with any medication, understanding the potential side effects is essential in assessing its overall safety profile.

In clinical trials, a percentage of men reported various forms of sexual dysfunction, including decreased libido, erectile dysfunction, and ejaculatory disorder, while taking finasteride. It's important to note that these side effects were reported in a relatively small number of cases compared to the overall study populations.

  • Decreased libido: The prevalence of libido decrease associated with finasteride use varies between 2.1% to 6.4% in different studies.
  • Erectile dysfunction: While studies report varying results, estimates indicate that erectile dysfunction may affect 1.3% to 18.5% of finasteride users.
  • Ejaculatory dysfunction: This includes a decreased volume of ejaculate and has been reported in approximately 0.8% to 1.4% of individuals taking finasteride.

Recent research has delved into the mechanisms behind these sexual side effects. Finasteride inhibits the conversion of testosterone to dihydrotestosterone (DHT), which plays a key role in both prostate health and hair growth. The reduction in DHT levels, while beneficial for prostate enlargement and hair loss, may also influence sexual function, given DHT's role in maintaining libido and erectile physiology.

It is also important to consider the concept of 'nocebo' effect – where experiencing negative side effects could be heightened due to the psychological anticipation of these symptoms following awareness of potential side effects - which can sometimes confound the understanding of finasteride's impact on sexual health.

Importantly, most studies indicate that these side effects are reversible upon discontinuation of the medication. However, there have been reports, albeit less common, of persistent sexual dysfunction even after stopping finasteride. These reports have led to further investigations, but a definitive causal relationship has been challenging to establish due to the variability in patient responses and the multifactorial nature of sexual dysfunction.

A critical review of the literature by a panel of experts, including urologists and endocrinologists, suggests that while there is a potential risk, the likelihood of persistent severe sexual dysfunction is low. They emphasize that when prescribing finasteride, clinicians should discuss potential sexual side effects with their patients, allowing for informed decision making.

Patients with concerns about the risks associated with finasteride should discuss these with their healthcare provider. Alternative treatments might be considered, depending on the individual's health profile, and the benefits versus risks ratio of the medication.

For those who are currently experiencing sexual dysfunction while taking finasteride or after discontinuation, consulting a healthcare professional is advised. This will ensure an appropriate evaluation, considering other potential causes of sexual dysfunction, such as psychological factors or other health conditions.

Overall, while the link between finasteride and sexual dysfunction is substantiated by clinical evidence, the individual's risk of developing such issues is variable and often reversible. The severity and duration of the side effects can differ, and many men take finasteride without experiencing any adverse effects on their sexual health.

Finasteride and the Risk of High-grade Prostate Cancer

Finasteride, a 5-alpha-reductase inhibitor, is frequently used in the treatment of benign prostatic hyperplasia (BPH) and male pattern baldness (androgenetic alopecia). Its primary function is to prevent the conversion of testosterone to dihydrotestosterone (DHT), a hormone that can contribute to prostate growth and hair loss in men. However, there have been concerns regarding the potential link between finasteride and an increased risk of high-grade prostate cancer, which is a more aggressive form of the disease.

These concerns stem largely from two major studies: the Prostate Cancer Prevention Trial (PCPT) and the Reduction by Dutasteride of Prostate Cancer Events (REDUCE) trial. The PCPT study, which involved finasteride, indicated a potential increased risk of high-grade prostate cancer in men taking the medication compared to those taking a placebo.

  • The PCPT found that while finasteride reduced the overall incidence of prostate cancer by about 25%, there was a relative increase in the incidence of high-grade tumors (Gleason score 8-10).
  • However, subsequent long-term follow-up studies have questioned the clinical significance of these findings, suggesting that finasteride may not actually increase the risk of high-grade prostate cancer, but rather, may improve the detection of these cancers due to a reduction in prostate size and increased sensitivity of prostate-specific antigen (PSA) testing.
  • Further analysis proposed that finasteride might lead to a more favorable pathology by making high-grade cancers easier to detect and diagnose earlier, potentially leading to more effective treatment.

Contrasting these findings, other studies have provided some reassurance about finasteride’s use:

  • A re-examination of the PCPT data indicated that men who took finasteride and developed prostate cancer had a lower risk of dying from the disease.
  • Research published in The New England Journal of Medicine concluded that there were no statistically significant differences in survival between the finasteride and placebo groups.
  • Another study found no evidence that finasteride was associated with a long-term increase in prostate cancer mortality.

Given the mixed evidence, it is essential for those considering or currently taking finasteride to talk to their healthcare provider about their individual risk. A comprehensive approach to this discussion should include:

  • A review of personal and family medical history, specifically related to prostate cancer.
  • Open communication regarding the benefits and potential risks of finasteride therapy.
  • Understanding the role of routine screening, including PSA tests, and how finasteride might affect such screenings.

It is also crucial to note that while finasteride has been flagged for a potential increase in high-grade prostate cancer risk, the overall evidence suggests that finasteride does not significantly affect long-term survival, particularly in regard to prostate cancer mortality. However, vigilance and continued research into this issue remain essential for healthcare providers and patients alike to make informed decisions regarding finasteride use.

Patients should not stop taking finasteride without consulting their healthcare provider, as abrupt discontinuation may lead to unwanted consequences or the return of symptoms related to BPH or male pattern baldness.

Use of Finasteride in Women: Concerns and Contraindications

Finasteride is a medication primarily used to treat male pattern baldness and benign prostatic hyperplasia (BPH). However, its use in women has been a topic of ongoing debate due to concerns around safety and efficacy. Since finasteride acts by inhibiting the enzyme that converts testosterone to dihydrotestosterone, a potent androgen associated with hair loss, it may seem a plausible treatment for androgenic alopecia in women. However, the data is limited and the risk profile is significant, particularly in certain populations.


One of the most significant contraindications for the use of finasteride in women is its teratogenic potential. Since finasteride can cause birth defects, particularly to the male fetus, it is absolutely contraindicated in pregnancy and in women who are of childbearing potential who are not using reliable contraception. The medication has Category X status by the FDA for pregnancy, indicating that the risks involved in use of the drug in pregnant women clearly outweigh potential benefits.

Postmenopausal Women

In postmenopausal women, the concerns are less about teratogenicity and more about the lack of significant evidence for efficacy. While some small studies suggest potential benefits for hair regrowth or reduction in hair thinning in postmenopausal women, large-scale robust trials are notably lacking. For example, a study published in the Journal of the American Academy of Dermatology in [Year] found that postmenopausal women with androgenic alopecia did not show a statistically significant difference in hair count between those treated with finasteride and those who received a placebo.

Polycystic Ovary Syndrome (PCOS) and Other Hormonal Conditions

Women with PCOS or other hormonal disorders that may result in elevated androgen levels sometimes consider the use of finasteride. However, the efficacy and safety profile in this subgroup is not well established, and due to the hormonal interplay within these disorders, such treatment should be approached with caution and under strict medical supervision. It's essential that patients consult with an endocrinologist or dermatologist specialized in hair disorders before starting finasteride.

Hormone-sensitive Cancers

Another major concern is the potential effect of finasteride on hormone-sensitive cancers. Women with a history of hormone-sensitive cancers, such as breast cancer, may be advised against the use of finasteride. Altered androgen metabolism potentially influences the pathophysiology of some breast cancers. Until there is more research clarifying the safety of finasteride in this population, it remains a contraindication.

Prescription Considerations

Although finasteride is not approved by the FDA for use in women, it may be prescribed off-label by some healthcare providers, particularly at different doses than those used for men. For instance, doses of 2.5 mg or 5 mg may be considered, higher than the 1 mg typically prescribed for male pattern baldness. This off-label use is not supported by formal guidelines and should only be considered in special circumstances with clear discussions about potential risks and benefits.


In summary, while there may be a role for the future use of finasteride in women with specific types of hair loss, current evidence does not broadly support this, and there are significant safety concerns, especially in women of childbearing potential. Patients and healthcare providers must engage in a careful consideration of the potential risks and benefits, alongside alternative treatment options, before initiating therapy with finasteride in women.

Long-term Use of Finasteride: What Research Shows

Finasteride, a medication primarily used to treat benign prostatic hyperplasia (BPH) and male pattern baldness, has been the subject of significant research regarding its long-term safety profile. When considering the chronic use of any medication, it is crucial to weigh the benefits against potential risks and side effects over an extended period.

Clinical Trials and Observational Studies: Several long-term clinical trials and observational studies provide insight into the effects of finasteride over extended use. For instance, a study published in the New England Journal of Medicine demonstrated that, over a seven-year period, finasteride reduced the risk of developing prostate cancer in men by about 25%. However, there was a modest increase in the incidence of high-grade prostate cancer.

  • Source: "The Influence of Finasteride on the Development of Prostate Cancer," N Engl J Med 2003.

Sexual Function: Regarding sexual health, some long-term users report experiencing persistent sexual side effects, such as erectile dysfunction, decreased libido, and ejaculatory disorders. A review in the Journal of Sexual Medicine discusses these concerns, pointing out that while these effects are relatively uncommon, they can persist even after discontinuation of the drug in a small subset of patients.

  • Reference: "Persistent Sexual Side Effects of Finasteride for Male Pattern Hair Loss," J Sex Med 2011.

Mental Health Impact: The potential impact of finasteride on mental health, particularly depression and cognitive changes, has been explored in a number of studies. Research published in the Journal of Clinical Psychiatry has suggested an association between finasteride use and an increased risk of depressive symptoms, advising physicians to discuss this possibility with patients.

  • Study: "Depression Circumstantially Related to the Administration of Finasteride for Androgenetic Alopecia," J Clin Psychiatry 2012.

Hormonal Changes: Finasteride's mechanism of action involves the inhibition of 5-alpha-reductase, which converts testosterone to dihydrotestosterone (DHT). Long-term suppression of DHT can result in hormonal imbalances that might have various systemic effects. However, the clinical significance of these hormonal changes over the long term remains a subject of ongoing investigation.

Risk of Prostate Cancer: Conflicting evidence exists regarding finasteride's role in prostate cancer risk with long-term use. While initial studies indicated a possible increase in high-grade prostate cancer risk, subsequent analyses have provided reassurance. A follow-up study in the Journal of the National Cancer Institute found that the overall survival rates of men taking finasteride were not significantly different from those who were not, suggesting a complex relationship between finasteride and prostate cancer risk.

  • Follow-Up Study: "Long-Term Survival of Participants in the Prostate Cancer Prevention Trial," J Natl Cancer Inst 2013.

Cardiovascular Risk: The impact of long-term finasteride use on cardiovascular health is another area explored by researchers. A population-based study found no significant increase in the risk of cardiovascular events in men who used finasteride for BPH, providing a level of reassurance for users with concerns about heart health.

  • Population-Based Study: "5α-Reductase Inhibitors and the Risk of Cardiovascular Events in Men with Benign Prostatic Hyperplasia," Eur Urol 2015.

These findings underscore the importance of ongoing dialogue between patients and healthcare providers regarding the benefits and risks of long-term finasteride use. While research provides valuable data, individual factors such as age, medical history, and concurrent medications must always be considered in the context of long-term treatment.

Alternatives to Finasteride for Hair Loss and Prostate Health

Finasteride is a well-known treatment for hair loss in men, particularly male pattern baldness, and benign prostatic hyperplasia (BPH), but it may not be suitable for everyone. Concerns about side effects or contraindications may lead some to seek alternatives. Here we will discuss both pharmaceutical and non-pharmaceutical options for individuals looking for alternatives to finasteride.

Pharmaceutical Alternatives

  • Minoxidil: This is an over-the-counter topical medication used to stimulate hair growth. Unlike finasteride, minoxidil works by enlarging the hair follicles and prolonging the growth phase of the hair cycle.
  • Dutasteride: Similar to finasteride, dutasteride inhibits the conversion of testosterone to dihydrotestosterone (DHT), but it is considered to be more potent. It's typically prescribed for BPH and, off-label, for hair loss.
  • Spironolactone: Although primarily used to treat fluid retention and high blood pressure, spironolactone has antiandrogen effects and may be used off-label to treat hair loss in women.
  • Tadalafil: For prostate health, tadalafil has been used to treat BPH. It works by relaxing the muscles in the bladder and prostate, helping to relieve urinary symptoms.

Natural and Non-Pharmaceutical Alternatives

  • Saw Palmetto: This is a natural remedy believed to inhibit 5-alpha-reductase, an enzyme involved in the conversion of testosterone to DHT, thereby potentially improving hair growth and prostate health.
  • Pumpkin Seed Oil: Rich in phytosterols, pumpkin seed oil has been studied for its potential benefits in combating hair loss.
  • Essential Oils: Some studies suggest that certain essential oils, such as rosemary oil, may promote hair growth with a safety profile that might be preferable for some users.
  • Pygeum: Derived from the bark of the African cherry tree, pygeum has been used to improve symptoms of BPH due to its supposed anti-androgenic effects.
  • Beta-Sitosterol: This plant-derived substance is sometimes used in tandem with saw palmetto to improve urinary symptoms associated with BPH.
  • Zinc: Zinc supplementation has been linked to reduced production of DHT and is often included in hair loss prevention supplements.

While each of these alternatives has its own potential benefits, it's critical to note that their effectiveness may vary from one individual to another. Additionally, the level of scientific evidence supporting their use also differs.

The choice of alternative treatments should be made based on personal health history, potential side effects, and in consultation with a healthcare provider. It's especially important for patients to discuss the use of natural supplements with their doctor, as these can still have interactions with other medications and may not be suitable for everyone.

Long-term safety and efficacy studies are more robust for some treatments, such as minoxidil, compared to more natural alternatives. However, emerging research continues to broaden our understanding of these treatments. For instance, a Journal of International Medical Research study found that a combination of saw palmetto and beta-sitosterol can significantly improve urinary symptoms in men with BPH. Conversely, a study published in JAAD stated that while the use of essential oils for hair growth is popular, more clinical studies are needed to establish their efficacy and safety profile.

Ultimately, the decision to pursue an alternative treatment to finasteride should be taken with a careful consideration of the risks, benefits, and the current state of research, ideally under the guidance of a healthcare professional.

Frequently asked questions

Most studies suggest that sexual side effects caused by finasteride, such as decreased libido, erectile dysfunction, and ejaculatory problems, are reversible upon discontinuation of the medication. However, there are reports of a small subset of men experiencing persistent effects, known as post-finasteride syndrome, though this is currently not well-understood.

Research has shown that finasteride can reduce the overall incidence of prostate cancer by about 25%. However, initial studies also suggested a relative increase in the occurrence of high-grade prostate cancer. Long-term follow-up studies have questioned these findings, suggesting that while finasteride may improve cancer detection, it doesn't necessarily increase the risk of high-grade cancers.

Finasteride is not FDA-approved for use in women and is contraindicated in women who are pregnant or of childbearing potential not using reliable contraception due to its teratogenic effects. While it may be prescribed off-label in some cases, such as for postmenopausal women or those with PCOS, it must be under strict medical supervision due to lack of substantial efficacy data and potential safety concerns.

For individuals taking finasteride for hair loss, results can vary. Typically, it may take at least three to six months of consistent usage to notice a slowing of hair loss or improvement in hair growth. Maximum benefits may take longer, possibly up to 12 months, and ongoing treatment is generally necessary to maintain the results.

Ask a question about Finasteride and our team will publish the answer as soon as possible.

Possible short-term side effects

  • sexual dysfunction
  • mood changes
  • gynecomastia
  • decreased psa levels

Possible long-term side effects

  • persistent sexual side effects
  • depression
  • cognitive changes
  • hormonal imbalances
  • increased high-grade prostate cancer risk


  • reduces male pattern hair loss
  • lowers bph symptoms
  • decreases prostate size
  • might lower need for bph-related surgery
  • may reduce overall prostate cancer risk

Healthier alternatives

  • minoxidil
  • dutasteride
  • spironolactone
  • tadalafil
  • saw palmetto
  • pumpkin seed oil
  • essential oils
  • pygeum
  • beta-sitosterol
  • zinc

Thank you for your feedback!

Written by Dr. Becky Maes
Published on: 02-07-2024

Thank you for your feedback!

Written by Dr. Becky Maes
Published on: 02-07-2024

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