Finasteride for Hair Loss
Finasteride is one of the most extensively studied medications available for male androgenetic alopecia, commonly known as male pattern hair loss.
It is a prescription 5 alpha reductase inhibitor that reduces the conversion of testosterone into dihydrotestosterone, or DHT. In genetically susceptible men, DHT contributes to the progressive miniaturization of scalp hair follicles that characterizes androgenetic alopecia.
Finasteride does not create new follicles and does not cure the genetic tendency to lose hair. Its primary role is to slow or stop further miniaturization, preserve existing hair and, in many men, increase the diameter and growth of miniaturized hairs.
The American Hair Loss Association considers finasteride one of the most important medical treatment options for appropriately diagnosed men with androgenetic alopecia.
The History of Finasteride
Finasteride was not originally developed as a hair loss medication.
Merck developed the drug to treat benign prostatic hyperplasia, or BPH. Finasteride 5 mg was approved in the United States under the brand name Proscar in 1992.
Researchers subsequently recognized that men taking finasteride could also experience improvement in scalp hair. This led to the development of a lower dose specifically for male pattern hair loss.
On December 19, 1997, the FDA approved finasteride 1 mg under the brand name Propecia for the treatment of male pattern hair loss in men.
The active medication in Proscar and Propecia is the same. The approved dose and indication are different. Proscar contains 5 mg of finasteride and is approved for BPH. Propecia contains 1 mg and is approved for male pattern hair loss.
Generic finasteride is now widely available.
How Finasteride Works
Testosterone can be converted into DHT by enzymes called 5 alpha reductases. Finasteride preferentially inhibits the form of this enzyme most important to DHT production within the hair follicle and prostate.
Men with androgenetic alopecia do not necessarily have abnormally high testosterone or DHT levels. The fundamental problem is the genetically determined sensitivity of susceptible follicles to androgen signaling.
As those follicles are repeatedly exposed to DHT, the growth phase becomes shorter and the hairs gradually become finer, shorter and less visible. This process is known as follicular miniaturization.
By reducing DHT, finasteride can slow or interrupt this process.
In a dose ranging study, finasteride 1 mg daily reduced scalp DHT by approximately 64 percent and serum DHT by approximately 71 percent after 42 days.
Finasteride does not suppress testosterone. Average circulating testosterone and estradiol levels can increase modestly after treatment begins but generally remain within the normal physiological range.
How Effective Is Finasteride?
Finasteride has unusually strong long term evidence for a hair loss medication.
In the pivotal clinical trials involving more than 1,500 men, finasteride 1 mg significantly improved hair counts, standardized photographs, physician assessments and patient assessments compared with placebo.
At 12 months, 86 percent of men treated with finasteride had no further decrease in target area hair count, compared with only 42 percent of men receiving placebo. Investigators rated 65 percent of men taking finasteride as having increased hair growth after one year.
The long term results are particularly important because androgenetic alopecia is progressive.
After five years, blinded photographic assessment found that 48 percent of men taking finasteride had increased visible hair, 42 percent showed no further visible progression and only 10 percent showed visible loss compared with baseline. In the placebo group, 75 percent showed visible progression.
This distinction matters.
Finasteride is primarily a preservation medication.
Regrowth can occur and can be cosmetically significant, but a man who maintains the same amount of hair for many years while his androgenetic alopecia would otherwise have progressed has achieved an important treatment success.
Does Finasteride Work on the Hairline and Crown?
Finasteride is often associated with treatment of the crown because many of the original clinical trials concentrated on vertex hair loss.
Clinical research has also demonstrated benefit in the frontal and anterior mid scalp.
Finasteride can slow loss and improve growth in these areas, but the FDA approved labeling does not claim established efficacy specifically for bitemporal recession. Regrowth of deeply recessed temples or areas where follicles have undergone advanced miniaturization should not be expected.
Finasteride can help preserve vulnerable frontal hair, but preservation and significant restoration are not the same thing.
The earlier treatment begins while viable miniaturized follicles remain, the more hair there is potentially available to preserve.
When Should Results Be Expected?
Hair grows slowly, so finasteride should not be judged after several weeks.
Changes can sometimes be detected within three months, but most men need approximately six to twelve months before the value of treatment can be assessed fairly.
Some men continue to improve beyond the first year.
Standardized photographs taken under the same lighting, angle, hair length and styling conditions are usually much more useful than repeatedly examining the hair in a mirror.
A treatment that appears to be doing nothing may actually be successfully preventing progression.
What Happens If Finasteride Is Stopped?
Finasteride controls androgenetic alopecia only while its biological effect is being maintained.
It does not permanently reset the follicle or eliminate the genetic tendency to lose hair.
When finasteride is discontinued, DHT activity returns and the follicles that were being protected by treatment again become vulnerable to miniaturization.
The treatment dependent benefit is generally lost over the following months, with prescribing information describing reversal of the treatment effect within approximately one year.
This does not mean that stopping finasteride makes someone lose more hair than he was genetically destined to lose. It means that the protection provided by the medication has been removed and the underlying condition continues.
The Standard Finasteride Dose
The FDA approved dose for male pattern hair loss is 1 mg once daily.
That dose has by far the largest body of controlled clinical evidence and remains the standard against which other finasteride regimens are compared.
But 1 mg is not the only dose that has demonstrated biological or clinical activity.
Dose ranging trials found meaningful hair growth benefit at 0.2 mg daily, while 1 mg and 5 mg produced similar average efficacy and performed better than the lower doses in the original development program.
This is why 1 mg was selected as the approved dose. It provided strong average efficacy without a meaningful average hair growth advantage from increasing the dose to 5 mg.
Finasteride Is Not Necessarily One Dose Fits All
Population averages do not mean that every patient responds identically.
Clinical response to finasteride can vary between individuals.
Some men appear to obtain excellent long term control of androgenetic alopecia with substantially less than 1 mg daily. Other men appear to respond more completely with greater exposure.
Hair loss physicians have therefore experimented for decades with lower doses, less frequent dosing, gradual titration and other individualized regimens.
These approaches are off label and do not have the same depth of controlled clinical outcome data as 1 mg daily.
There is, however, a biological basis for lower dosing. Dose ranging research demonstrated that relatively small amounts of finasteride can produce substantial reductions in both serum and scalp DHT. Finasteride 0.2 mg daily, for example, produced DHT reductions surprisingly close to those seen with 1 mg.
This means that lower dose does not mean no biological effect.
It also helps explain why some men can maintain substantial benefit at doses below the standard 1 mg regimen.
Can Lowering the Dose Reduce Side Effects?
This is an important area where controlled trials and clinical practice do not provide exactly the same type of information.
The original hair loss trials were not designed to determine precisely how every sexual, psychological or other adverse effect changes when men move between very low or intermittent dosing schedules.
In clinical practice, however, physicians have observed that some men who develop adverse effects at a higher exposure can tolerate a lower dose or less frequent dosing with reduced symptoms or complete resolution while continuing to obtain hair preservation.
That does not happen in every patient.
Because even low doses can substantially suppress DHT, reducing the dose does not guarantee that an adverse effect will disappear.
But it is equally misleading to suggest that dose reduction cannot matter.
Individual drug exposure, tissue response, sensitivity and tolerability vary.
For some men, careful titration can provide an alternative to an all or nothing decision between taking 1 mg every day and abandoning finasteride entirely.
The American Hair Loss Association believes that individualized dosing should be discussed with the prescribing physician when appropriate rather than assuming every patient must be managed identically.
Does 5 mg Work Better Than 1 mg?
In the original dose ranging trials, 1 mg and 5 mg produced similar average hair growth results.
For that reason, taking 5 mg every day should not automatically be assumed to provide five times the hair benefit or even substantially greater average efficacy.
At the same time, clinical response varies between individuals, and some physicians have observed differences in particular patients when exposure is adjusted.
The important distinction is between what was demonstrated on average in clinical trials and what may occur in an individual patient.
More drug is not automatically better, and any change in dose should take both efficacy and tolerability into account.
Less Frequent and Intermittent Dosing
Some physicians use finasteride less frequently than once daily, particularly when attempting to identify the lowest effective exposure for an individual patient.
Finasteride disappears from the bloodstream relatively quickly, but its biological effect on DHT does not disappear at exactly the same rate. This is one reason less frequent dosing has been explored in clinical practice.
Controlled hair growth evidence remains strongest for daily treatment, and intermittent schedules should not be presented as equivalent simply because they can reduce DHT.
However, clinical experience indicates that some men can maintain satisfactory control using less frequent dosing.
The relevant question is not simply how many tablets someone takes. It is whether the regimen provides adequate long term control of miniaturization with acceptable tolerability.
Finasteride and Minoxidil
Finasteride and minoxidil work through different mechanisms.
Finasteride primarily addresses the androgen driven miniaturization process by reducing DHT. Minoxidil acts as a growth stimulant and does not directly reduce DHT.
For this reason, the medications can be complementary.
Clinical research has shown that combination therapy can produce greater average improvement than either treatment alone in some men.
Not everyone needs both treatments, and adding medications simply because they are available is not necessarily the best strategy.
A man who is stable and satisfied on finasteride alone may have little reason to complicate his regimen. Someone seeking greater growth or who has an incomplete response may discuss combination treatment with his physician.
Finasteride Side Effects: What Did the Original Trials Show?
Finasteride is well tolerated by most men who take it, but adverse effects are real and should neither be dismissed nor exaggerated.
In the original controlled trials of finasteride 1 mg, decreased libido was reported in approximately 1.8 percent of men taking finasteride compared with 1.3 percent receiving placebo.
Erectile dysfunction was reported in approximately 1.3 percent compared with 0.7 percent.
Ejaculation disorders were reported in approximately 1.2 percent compared with 0.7 percent.
Overall, approximately 3.8 percent of men receiving finasteride reported one or more of these sexual adverse effects compared with 2.1 percent receiving placebo.
Many of these adverse effects resolved after treatment was stopped, and many also resolved while treatment was continued.
Controlled trials and systematic reviews nevertheless support a real increase in the risk of sexual adverse effects compared with placebo.
Other Reported Adverse Effects
Other adverse events reported with finasteride include changes in ejaculate volume, testicular pain, breast tenderness or enlargement, allergic reactions and depression.
Postmarketing reports have also included male infertility or reduced semen quality, persistent sexual dysfunction after discontinuation and rare reports of male breast cancer.
A postmarketing report does not establish how often an event occurs or prove that finasteride caused every reported case.
Men who develop a breast lump, nipple discharge, significant breast enlargement or persistent breast pain should have the change medically evaluated.
Finasteride and Fertility
Finasteride does not appear to impair fertility in most healthy men.
In a controlled study of healthy young men taking 1 mg daily for 48 weeks, finasteride did not significantly affect sperm concentration, total sperm count, motility or morphology.
That does not mean fertility effects never occur.
Men evaluated in infertility clinics have been reported to experience substantial reductions in sperm count while taking finasteride, with improvement after the medication was stopped.
This suggests that some men with underlying or marginal fertility may be more susceptible than the average healthy study participant.
A man who is having difficulty conceiving, already has abnormal semen parameters or has specific fertility concerns should discuss finasteride with his physician. Semen testing can be considered when clinically appropriate.
Finasteride should not automatically be assumed to cause permanent infertility, and it should not automatically be assumed to have no effect in every individual.
Mood Changes and Suicidal Thoughts
Psychiatric adverse effects have become an increasingly important part of the finasteride safety discussion.
Depression has been included in postmarketing information for finasteride for years.
In 2025, the European Medicines Agency completed a broad safety review and concluded that suicidal ideation should be recognized as an adverse effect of oral finasteride tablets, although available data do not allow its frequency to be reliably estimated.
The same review concluded that the overall benefits of finasteride continued to outweigh its risks for approved uses.
Pharmacovigilance research has also identified disproportionate reporting of depression and suicidality, particularly among younger men taking finasteride for hair loss.
These databases are useful for detecting possible safety signals, but they cannot establish the true incidence of an adverse effect because they do not contain a controlled population of all people taking the medication.
Men who experience significant depression, major changes in mood or suicidal thoughts while taking finasteride should seek medical attention promptly. Current European guidance advises men taking finasteride 1 mg for hair loss to stop treatment and seek medical advice if depression, depressed mood or suicidal thoughts occur.
Persistent Symptoms and Post Finasteride Syndrome
Few subjects in modern hair loss treatment have generated more controversy than reports of symptoms that continue after finasteride has been discontinued.
The term post finasteride syndrome, often abbreviated PFS, is used to describe a collection of reported persistent sexual, physical, cognitive and psychological symptoms following finasteride exposure.
Reported symptoms have included erectile dysfunction, reduced libido, orgasm and ejaculation changes, changes in genital sensation, depression, anxiety, cognitive complaints, sleep disturbances and other symptoms.
Persistent sexual dysfunction after discontinuation is included in United States postmarketing information for finasteride.
The existence of persistent symptoms in some patients therefore should not simply be dismissed.
What remains unresolved is how frequently persistent symptoms occur, what causes them, whether all symptoms grouped under PFS share one mechanism and whether PFS represents a single definable medical syndrome.
There is currently no laboratory test that diagnoses PFS and no established biological marker that determines who will develop persistent symptoms.
The Irwig Reports and the Beginning of the Modern PFS Debate
One of the most influential early publications surrounding persistent finasteride symptoms was published by endocrinologist Michael Irwig and a colleague in 2011.
They interviewed 71 otherwise healthy men who reported new sexual symptoms after taking finasteride and who said those symptoms had persisted for at least three months after stopping treatment.
The publication drew significant attention because the reported symptoms were severe and persistent.
But it is important to understand what the study could and could not establish.
The participants were selected because they already reported persistent problems associated with finasteride.
The study was not a randomized trial of finasteride users. It did not begin with a representative group of men starting the medication and then determine what percentage developed persistent symptoms.
Recruitment included men from an online community specifically devoted to persistent adverse effects attributed to 5 alpha reductase inhibitors.
The authors themselves acknowledged important limitations including selection bias, recall bias and the absence of objective baseline measurements.
A later follow up found that persistent symptoms remained in many members of that already selected group.
That was useful information about the experience of those particular men.
It could not establish how often the same outcome occurs among the much larger population of men who take finasteride.
The Irwig publications helped bring attention to a legitimate safety question. They did not establish the incidence of post finasteride syndrome.
The Internet, Nocebo Effects, and Stimulated Reporting
The public environment surrounding finasteride changed dramatically after persistent symptom reports began circulating widely online.
Dedicated forums, patient communities, social media, advocacy groups and extensive media coverage made potential finasteride adverse effects much more visible.
Expectation can influence the experience and reporting of symptoms.
In a controlled study involving men taking finasteride 5 mg for BPH, participants who were specifically informed about possible sexual adverse effects reported them much more frequently than men taking the same medication who were not given that information.
This is an example of a nocebo effect, in which negative expectations can contribute to the development or perception of symptoms.
Pharmacovigilance research has also found that reports of psychological and sexual adverse events increased substantially after the finasteride controversy became widely publicized. This phenomenon is often referred to as stimulated reporting.
Neither phenomenon proves that reported adverse effects are imaginary.
A genuine drug effect, individual vulnerability, heightened symptom awareness, nocebo effects and stimulated reporting can all exist at the same time.
The mistake is to choose only one explanation.
Patients reporting symptoms deserve to be taken seriously. At the same time, internet anecdotes, self selected surveys and spontaneous adverse event databases should not be used to estimate risk as though they were randomized controlled trials.
What Does the Evidence Say About Post Finasteride Syndrome Today?
The answer remains more complicated than either side of the public debate often suggests.
Controlled trials clearly demonstrate that finasteride can cause sexual adverse effects in a minority of men.
Postmarketing data and observational research demonstrate that persistent symptoms have been reported after discontinuation.
Research continues into possible biological mechanisms, including pathways involving neurosteroids and other consequences of 5 alpha reductase inhibition.
But the true incidence of persistent symptoms remains unknown, and no single accepted mechanism explains all of the symptoms attributed to PFS.
Many studies specifically investigating PFS have involved self selected or already symptomatic populations, which makes it difficult to determine causation or population risk.
Finasteride should therefore not be described as risk free. Persistent symptoms should also not be presented as an inevitable or common outcome when the available evidence does not establish that.
The unanswered questions deserve continued research.
Finasteride and PSA Testing
Finasteride lowers prostate specific antigen, or PSA.
This matters because PSA is commonly used as part of prostate cancer screening and evaluation.
Even the 1 mg hair loss dose can meaningfully lower PSA. In a randomized study of men aged 40 to 60, median PSA decreased approximately 40 percent in men aged 40 to 49 and approximately 50 percent in men aged 50 to 60 after 48 weeks of finasteride 1 mg.
Any physician interpreting a PSA result needs to know that the patient is taking finasteride.
A PSA value should not simply be interpreted as though the patient were untreated.
An increase from a patient’s lowest PSA value while taking finasteride may also require evaluation even if the absolute number still appears to fall within a conventional reference range.
Finasteride and Prostate Cancer
Finasteride has also been studied extensively in prostate cancer prevention, although those studies used the 5 mg dose, not the 1 mg hair loss dose.
The large Prostate Cancer Prevention Trial found approximately a 25 percent reduction in prostate cancer diagnosesamong men receiving finasteride during the original trial.
The original analysis also found more diagnoses of high grade prostate cancer in the finasteride group, which created significant concern.
Subsequent analyses investigated whether improved cancer detection in the smaller prostates of men taking finasteride contributed to that finding.
Most importantly, long term follow up did not demonstrate an increase in prostate cancer mortality among men assigned to finasteride.
These findings should not be interpreted to mean that finasteride 1 mg should be taken to prevent prostate cancer. Finasteride is not FDA approved for prostate cancer prevention.
They are nevertheless important context when discussing the long term systemic effects of 5 alpha reductase inhibition.
Can Finasteride Cause an Initial Shed?
Some men report increased shedding after beginning finasteride.
Finasteride changes the biological environment surrounding susceptible follicles, so temporary changes in hair cycling and shedding are possible.
However, the controlled finasteride trials did not establish a predictable early shedding phase in the same way that transient shedding is commonly recognized with minoxidil.
A temporary increase in shedding does not automatically mean treatment is failing, but substantial or persistent shedding should not simply be attributed to finasteride without considering other causes such as telogen effluvium or progression of the underlying hair loss.
Can Finasteride Be Used With Other Medications?
Finasteride has relatively few clinically important drug interactions.
That does not mean an individual patient should assume every combination is appropriate.
A prescribing physician should know about all medications, supplements and relevant medical conditions, particularly when multiple hair loss treatments are being combined.
Finasteride and Women
Finasteride 1 mg is FDA approved for male pattern hair loss and is not FDA approved for female pattern hair loss.
A controlled trial of 1 mg daily in postmenopausal women did not demonstrate meaningful efficacy.
Higher doses of finasteride have nevertheless been used off label by hair loss specialists in selected women, particularly women who cannot become pregnant. The evidence is much less established than it is for men.
Finasteride can interfere with normal development of the external genitalia of a male fetus. It should not be used during pregnancy.
Women who are pregnant or may become pregnant should not handle crushed or broken finasteride tablets. Intact tablets are coated and prevent direct contact with the active medication during ordinary handling.
Finasteride and Blood Donation
People taking finasteride should be aware that blood donation organizations impose a temporary deferral because donated blood could potentially be given to a pregnant recipient.
The American Red Cross currently requires a one month waiting period after the last dose of finasteride before blood donation.
This is different from dutasteride, which requires a considerably longer deferral because it remains in the body much longer.
Topical Finasteride
Topical finasteride is finasteride applied directly to the scalp rather than swallowed.
The goal is to produce meaningful inhibition of DHT within the scalp while reducing systemic drug exposure.
The concept is supported by controlled clinical research.
A Phase III randomized trial of a standardized topical finasteride spray found significant improvement in hair count compared with placebo, with efficacy numerically similar to oral finasteride over the study period.
Systemic finasteride exposure was substantially lower with the topical formulation, and average serum DHT suppression was also lower than with oral finasteride.
That does not mean topical finasteride remains entirely within the scalp.
Finasteride applied to the skin can enter the bloodstream and can produce systemic DHT suppression.
Topical Finasteride in the United States
There is currently no FDA approved topical finasteride product in the United States.
Most topical finasteride products sold in the United States are compounded preparations, frequently offered through telehealth companies, specialty pharmacies and hair loss practices.
These formulations can differ considerably in concentration, vehicle, application volume and combination ingredients.
A compounded topical finasteride product should not automatically be assumed to have the same pharmacokinetics, systemic exposure or clinical evidence as a standardized formulation used in a published trial.
Compounded medications are not FDA approved and are not reviewed by the FDA for safety, effectiveness or manufacturing quality before marketing in the same way as approved drugs.
The FDA Warning About Compounded Topical Finasteride
In 2025, the FDA issued a specific safety alert concerning compounded topical finasteride.
The agency reported receiving adverse event reports involving compounded topical products, including sexual, psychiatric and other systemic symptoms.
The FDA emphasized that systemic absorption through the skin is expected and warned against telling consumers that topical finasteride carries no possibility of systemic adverse effects simply because it is applied to the scalp.
The agency also warned about unintended exposure to other people through skin contact, which is particularly important around women who are or may become pregnant.
Spontaneous adverse event reports cannot establish how frequently these problems occur or prove causation in every case.
The warning does establish something important for consumers:
Topical finasteride should not be marketed as a risk free version of oral finasteride.
Is Topical Finasteride Safer Than Oral Finasteride?
A well designed topical formulation can produce substantially lower systemic finasteride exposure and less reduction in circulating DHT than oral treatment.
That creates a reasonable basis for expecting lower systemic exposure with an appropriately formulated topical product.
But topical formulations are not all equivalent.
Concentration, dose delivered to the scalp, application area, vehicle and frequency all affect systemic exposure.
Someone applying a high concentration compounded product over a large area may have a very different exposure from someone using the standardized low volume spray studied in clinical trials.
The most accurate answer is therefore:
Topical finasteride can reduce systemic exposure, but it does not eliminate systemic exposure or systemic risk.
Topical Finasteride With Minoxidil
Finasteride and minoxidil are frequently combined in topical formulations.
Randomized studies have found that topical finasteride combined with minoxidil can produce greater average improvement than minoxidil alone in some men.
Combination products may be convenient, but they also create practical disadvantages.
If a patient develops irritation or another adverse effect, it can be more difficult to determine which ingredient is responsible. Changing the dose of one medication without changing the other may also be impossible in a fixed combination.
A compounded combination should therefore not automatically be considered superior simply because it contains more active ingredients.
Finasteride or Dutasteride?
Finasteride and dutasteride are both 5 alpha reductase inhibitors, but they are different medications.
Finasteride primarily inhibits the form of 5 alpha reductase most relevant to the hair follicle.
Dutasteride inhibits multiple forms of the enzyme and produces more extensive suppression of DHT.
Some comparative studies have found greater average hair growth with dutasteride.
Dutasteride is not FDA approved for hair loss in the United States and has a much longer half life, meaning that the drug remains in the body for considerably longer after treatment is stopped.
Greater DHT suppression does not automatically make dutasteride the better treatment for every patient.
A man doing extremely well on finasteride with good tolerability may have little reason to escalate treatment simply because another medication suppresses more DHT.
What Should Someone Consider Before Starting Finasteride?
Finasteride should be used in the context of an accurate diagnosis of androgenetic alopecia rather than simply because someone notices increased shedding.
The potential value is greatest while there is still meaningful hair to preserve.
Waiting until follicles have undergone extensive miniaturization for many years reduces what any medication can realistically accomplish.
Before starting treatment, a man should understand the expected benefit, the need for continued treatment, the possibility of sexual and psychiatric adverse effects, the unresolved questions surrounding persistent symptoms, fertility considerations where relevant and the effect of finasteride on PSA testing.
Baseline photographs are extremely valuable.
Someone particularly concerned about sexual function, fertility or another issue may also want to discuss establishing an appropriate baseline with his physician before treatment.
The AHLA Perspective
Finasteride has been used for male pattern hair loss for nearly three decades and remains one of the most effective and extensively studied medications available for androgenetic alopecia.
Its benefits should not be exaggerated.
Its adverse effects should not be minimized.
And the legitimate safety discussion should not be distorted in either direction.
Most men in controlled trials did not experience sexual adverse effects. Some men clearly do. Persistent symptoms have been reported and deserve serious investigation. The true incidence and biological explanation for persistent symptoms remain unresolved.
Likewise, clinical trials establish 1 mg daily as the standard dose, but that does not mean every man requires exactly the same exposure. Lower doses can produce substantial biological activity, individual response varies, and careful dose titration has been used successfully in clinical practice.
The same principle applies to topical finasteride. It can offer lower systemic exposure, but it is not simply oral finasteride without systemic risk.
The American Hair Loss Association believes men deserve enough information to make a genuinely informed decision rather than being told either that finasteride is completely harmless or that taking it is likely to result in permanent disability.
For many appropriately diagnosed men, finasteride can preserve hair for years or decades and materially alter the course of androgenetic alopecia. The decision to use it should be based on accurate diagnosis, realistic expectations, informed discussion of risk and an individualized long term treatment strategy.
Used for: Male Pattern Baldness
Selected References
- U.S. Food and Drug Administration. Propecia 1 mg Approval Letter. December 19, 1997. FDA approval letter
- U.S. National Library of Medicine. Propecia, finasteride 1 mg, Full Prescribing Information. DailyMed. Full prescribing information
- Kaufman KD, Olsen EA, Whiting D, et al. Finasteride in the treatment of men with androgenetic alopecia.Journal of the American Academy of Dermatology. 1998;39:578 to 589. doi:10.1016/S0190 9622(98)70007 6. PubMed
- Drake L, Hordinsky M, Fiedler V, et al. The effects of finasteride on scalp skin and serum androgen levels in men with androgenetic alopecia. Journal of the American Academy of Dermatology. 1999;41:550 to 554. PubMed
- Roberts JL, Fiedler V, Imperato McGinley J, et al. Clinical dose ranging studies with finasteride, a type 2 5 alpha reductase inhibitor, in men with male pattern hair loss. Journal of the American Academy of Dermatology. 1999;41:555 to 563. PubMed
- Leyden J, Dunlap F, Miller B, et al. Finasteride in the treatment of men with frontal male pattern hair loss.Journal of the American Academy of Dermatology. 1999;40:930 to 937. doi:10.1016/S0190 9622(99)70081 2. PubMed
- Finasteride Male Pattern Hair Loss Study Group. Long term five year multinational experience with finasteride 1 mg in the treatment of men with androgenetic alopecia. European Journal of Dermatology. 2002;12:38 to 49. PubMed
- Mella JM, Perret MC, Manzotti M, Catalano HN, Guyatt G. Efficacy and safety of finasteride therapy for androgenetic alopecia: a systematic review. Archives of Dermatology. 2010;146:1141 to 1150. doi:10.1001/archdermatol.2010.256. PubMed
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- D’Amico AV, Roehrborn CG. Effect of 1 mg per day finasteride on concentrations of serum prostate specific antigen in men with androgenic alopecia: a randomised controlled trial. Lancet Oncology. 2007;8:21 to 25. doi:10.1016/S1470 2045(06)70981 0. PubMed
- Irwig MS, Kolukula S. Persistent sexual side effects of finasteride for male pattern hair loss. Journal of Sexual Medicine. 2011;8:1747 to 1753. doi:10.1111/j.1743 6109.2011.02255.x. PubMed
- Mondaini N, Gontero P, Giubilei G, et al. Finasteride 5 mg and sexual side effects: how many of these are related to a nocebo phenomenon? Journal of Sexual Medicine. 2007;4:1708 to 1712. doi:10.1111/j.1743 6109.2007.00563.x. PubMed
- Nguyen DD, Marchese M, Cone EB, et al. Investigation of suicidality and psychological adverse events in patients treated with finasteride. JAMA Dermatology. 2021;157:35 to 42. doi:10.1001/jamadermatol.2020.3385. PubMed
- Piraccini BM, Blume Peytavi U, Scarci F, et al. Efficacy and safety of topical finasteride spray solution for male androgenetic alopecia: a Phase III randomized controlled clinical trial. Journal of the European Academy of Dermatology and Venereology. 2022;36:286 to 294. doi:10.1111/jdv.17738. PubMed
- Suchonwanit P, Srisuwanwattana P, Chalermroj N, Khunkhet S. A randomized double blind controlled study of topical finasteride combined with minoxidil compared with minoxidil alone in male androgenetic alopecia.Journal of the European Academy of Dermatology and Venereology. 2018;32:2257 to 2263. doi:10.1111/jdv.15171. PubMed
- U.S. Food and Drug Administration. FDA alerts health care providers, compounders and consumers of potential risks associated with compounded topical finasteride products. 2025. FDA safety alert
- European Medicines Agency. Finasteride and dutasteride containing medicinal products: measures to minimise the risk of suicidal thoughts. 2025. EMA safety review
- Thompson IM, Goodman PJ, Tangen CM, et al. The influence of finasteride on the development of prostate cancer. New England Journal of Medicine. 2003;349:215 to 224. doi:10.1056/NEJMoa030660. PubMed
- Goodman PJ, Tangen CM, Darke AK, et al. Long term effects of finasteride on prostate cancer mortality. New England Journal of Medicine. 2019;380:393 to 394. doi:10.1056/NEJMc1809961. PubMed
- American Red Cross. Blood Donor Eligibility Criteria: Finasteride and Dutasteride. American Red Cross eligibility information