Can Finasteride Shrink an Enlarged Prostate?

by Ben Ong
Reading Time: 7 minutes

finasteride enlarged prostate

An enlarged prostate is a condition that affects a large number of men, with the latest statistics showing that by the age 60, 50% of men will have some signs of BPH (benign prostatic hyperplasia).

While this itself does not mean that you have prostate cancer, an enlarged prostate can result in a number of painful and embarrassing symptoms.

To resolve these symptoms of BPH, a drug by the name of finasteride is commonly prescribed. However, a staggering amount of research has highlighted worrying side effects attributed to this popular drug.

This in-depth report will take a closer look at Finasteride and to what extent does its harm, rather than improve your prostate health.


How was Finasteride created?finasteride enlarged prostate

Roy Vagelos, an American physician and business executive, who was president of the pharmaceutical company Merck & Co, initially developed Finasteride in 1975.

His inspiration stemmed from a report he read, written by Dr.Julianne Imperato-McGinley, an endocrinologist at Cornell Medical College.

Dr. Imperato reported a condition suffered by children from a small village in the Dominican Republic. A number of these children appeared sexually ambiguous at birth and were initially raised as girls. However, shortly after puberty, they grew external male genitalia and other masculine characteristics.

This breaking research discovered that these children shared a genetic mutation. The mutation caused a deficiency of an enzyme which transforms testosterone into dihydrotestosterone (DHT). DHT is, of course, a more potent form of testosterone which drives puberty in young boys and prostatic tissue growth in older men.

The name of the affected enzyme was 5-αlpha reductase. The low levels of DHT caused these kids to lack sexual characteristics, including external testicles and a penis.

During puberty, the natural increase in testosterone levels allowed sexual differentiation, but there were some differences for normal individuals.

One of them was an affected prostate, which was much smaller than normal and under-developed. Later on in life, they also seemed to lack incidence of male pattern baldness.

Based on this investigation, Merck & Co wanted to create a drug that would produce the same being prostate shrinking and baldness preventing effects.

This led to the development of Finasteride, approved in 1992 by the U.S Food and Drug Administration (FDA) for the treatment of BPH.

The drug was marketed under the brand name Proscar and in 1997, Merck was obtained FDA approval for a second lower dose version for the treatment of Male Pattern Baldness (MPB). This was marketed under the brand name Propecia.


How does Finasteride work?

Finasteride is a 5-alpha-reductase inhibitor, meaning it prevents the enzyme 5-alpha-reductase from converting testosterone into DHT.

Prostate growth and size is largely dependent on DHT levels. There are two types of 5 αlpha-reductase; type 1 which is present in tissue, such as liver or skin and type 2, which is the predominant type present in the prostate.

This enzyme is critical to the normal development of the prostate and hyperplastic growth later in life. Finasteride acts as an inhibitor of type 2 5α-reductase enzyme.

Studies have revealed that Finasteride reduces intraprostatic DHT level by 91.4%. However, despite the concerns about this substantial reduction, advocates and Merck have argued Finasteride does not reduce DHT level so much as to chemically castrate you.

This is because circulating testosterone is converted to DHT by the type 1 isoenzyme, existing in the skin and liver. This being said Finasteride may have the worst sexual side effects of all of the drugs examined in this report.

By lowering DHT levels Finasteride actively decreases the size of the prostate. However, this process takes between 3 and 6 months before the clinical effects kick in and the prostate reduces in size.

Therefore, the efficacy of finasteride and 5 alpha-reductase inhibitors cannot be felt till a patient has been on the medication for a very long period of time. Unfortunately, side effects can begin to manifest in a matter of days or weeks and can get worse over time.

Finasteride is most often prescribed for men with substantially enlarged prostates, prostates above 40 or 50 grams. These are men who are at the greatest risk of disease progression, experience moderate-to-severe lower urinary tract symptoms, and acute urinary retention.

Is Finasteride safe? Does it have side effects? finasteride enlarged prostate

To evaluate the safety of Finasteride, a 4-year placebo-controlled study of 1,524 patients treated with Finasteride and 1516 patients treated with placebo were followed over a period of 4 years.

The most frequently reported adverse reactions were related to sexual function

  • 8.1 % of men reported regular impotence
  • 6.4 % of men reported decreased libido
  • 3.7% of men saw a decreased volume of ejaculate

Less common side effects include the growth of male breasts; tenderness, soreness, and pain in male breasts; rashes, allergic reactions, itching, hives, and swelling of the lips and face.

Some men reported testicular pain, and there was a weak link to increased risk of developing male breast cancer.

Other studies have since reported that Finasteride may reduce the incidence of prostate cancer, although these are controversial results. It appears that Finasteride may lower your risk of slow-growing prostate cancers while increasing your risk of aggressive prostate cancer.


The largest study investigating prostate cancer prevention with Finasteride was published in 2003. It found a 24.8% risk reduction in the prevalence of prostate cancer over seven years. However, it also noted an alarming increase in high-grade 7 or above tumors in the Finasteride group (37%) versus the placebo group (22%).  

According to Patrick C. Walsh, M.D., University Distinguished Service Professor of Urology at Johns Hopkins Medicine, Finasteride prevents you from knowing that you could have prostate cancer. Even worse, taking finasteride may mask the signs of aggressive – yet curable – prostate cancers until later in their growth, which may make them more lethal.

New research also shows that the sexual and cognitive side effects of finasteride can persist for as long as 10 years after men stopped taking the drug. A 2014 meta study coined the phrase “Post Finasteride Syndrome”, and noted that “Many clinicians are unaware of the scope of the persistent physical and psychological adverse effects of finasteride. Symptoms range from minor to severe.”

The meta study examined 12 research papers that all showed high percentages (80-90+ percent) showing persistent and long-lasting sexual and psychological side effects.

A Notable 2011 research paper had the highest percentages: “96% of the men in the study who took finasteride experienced sexual problems lasting for more than a year after they stopped taking the drug.”

In another large-scale drug report from 2017, 103 young men (16-42 years old) who were taking low dose finasteride for hair loss developed ED. In a third of them (33%), ED persisted after stopping the medication.

The study also noted that the longer men took finasteride or dutasteride, the higher their risk. Men who had taken finasteride for a period of 205 days had a 4.9-fold higher risk of Persistent Erectile Dysfunction (PED) than men with shorter exposure.

Does Finasteride alleviate symptoms?

Just after it was approved by the FDA, a large-scale study was conducted examining the efficacy of Finasteride. 895 subjects with BPH were randomized to receive placebo or 1 or 5 mg of Finasteride over 1 year (Gormley, 1992). The primary outcome measures consisted of a symptom score and a peak flow rate, although measurements of prostate size were also recorded.

The symptom score measures the total scores of nine symptoms: (Infographic)

  1. Decreased urinary stream
  2. Dribbling
  3. Interruption in the stream
  4. Hesitancy
  5. Feeling of incomplete emptying
  6. Straining to initiate flow
  7. Urgency
  8. Incontinence
  9. Dysuria

The group taking the normal 5 mg oral dose of finasteride per day showed a statistical improvement in symptoms (21% improvement) compared with the placebo group (just 2%). Another group taking a lower dose of finasteride (1mg oral per day) saw no statistical improvement in symptoms over the placebo group.

Further studies have demonstrated that this response is associated with prostate size at the beginning of the treatment.  Boyle et al, 1996, undertook a meta-analysis of six randomized, placebo-controlled clinical trials to provide a more thorough consensus. The conclusion was that men with smaller prostate saw little-to-no symptomatic relief when compared to men with larger prostates. Approximately 80% of the variation in treatment effect between studies was attributed to differences in mean prostate size.  The beneficial effects are most pronounced in men with enlarged prostates (>25 mL).

In general, Finasteride seems to cause a modest improvement to BPH symptoms after being taken for a 12-month period.

Does Finasteride shrink and heal the prostate? 

finasteride enlarged prostate

Finasteride does shrink the prostate and therefore appears to have some benefit. The benefits are most visible for men with prostates larger than 40 g and it offers some symptomatic relief (approximately a 20% improvement over a year) by reducing the size of the prostate.

Studies have shown that the reduction in prostate size is sustained for 5 years following a course of Finasteride treatment. They also note that the majority of the benefits and effects of Finasteride on prostate size will be achieved within 6 months (Gormley, 1992).


Finasteride Conclusion 

The above study is useful as it shows the wide variations among BPH patient response to Finasteride treatment. As with all drugs, your body will react differently to other men. You may experience many or only a few side effects, and the drugs may be more or less effective for you.  

You should consider the following factors when deciding whether or not to take finasteride; Firstly, prostate size, as that is the largest indicator of whether or not finasteride is going to be effective.

Second, you should consider whether or not you can wait 6-12 months for an average 20% reduction in symptoms. Next, the decreased risk of less aggressive cancers to the increased risk of more aggressive cancers should be considered.  Then the mental side effects on mood and cognitive decline.

Finally, based on feedback from our clinical and customer service teams, the primary complaint and regret from men who take Finasteride are the sexual side effects. Studies have shown that Finasteride induced sexual dysfunction can last for many months or even years before you would regain full or even partial sexual function.

Naturally Treat An Enlarged Prostate

When it comes to treating prostate problems, natural is the way to go. That’s why Ben’s Total Health contains 23 powerful herbal ingredients combined in one supplement designed to supercharge your prostate treatment.

Prostate cancer rates are higher than ever before and sadly many men are unknowingly relying on dangerous prostate drugs with life-wrecking side effects.

With natural, herbal remedies you can treat your prostate naturally, safely and with no nasty side effects.


finasteride enlarged prostate

  • Finasteride has many concerning side effects that persist even after you stop taking it.
  • It takes 6 months to start working.
  • Finasteride may cause long-term sexual dysfunction.
  • Finasteride may accelerate cognitive decline.
  • It may lower the risk of some forms of prostate cancers.
  • It may increase the risk of aggressive prostate cancer.

Remember: Caution and surveillance are recommended for patients taking this medication.

Can Finasteride Shrink an Enlarged Prostate?
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About Ben Ong

Ben Ong is a best-selling author and widely regarded as one of the world’s leading experts on natural treatments for metabolic conditions such as prostate disease and type 2 diabetes. He founded Ben’s Natural Health and has worked for over 20 years providing a range of high quality, clinically effective, all-natural supplements for BPH, high PSA, high blood sugar, sexual dysfunction, and others.
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  1. Robert Wagner

    My PSA level at 67 is 6.1. I would like to see if there is a natural way to reduce it. I have had a biopsy which was negative and a MRI which also showed nothing. They were done in early 2018. My doctor wants to do another prostate biopsy, which I have delayed for 6 months. (Not a pleasant procedure.) Any recommendations?

  2. Douglas Clark

    I would like to know what to take to srink my enlarged prostate and deal with estrogen in my system ,so can some one please tell me what i can start on thank you

    • Ben Ong

      Hi Douglas, Total Health for the prostate is formulated with natural 5 alpha-reductase inhibitors and powerful natural ingredients that lower DHT levels and reduces the size of the prostate gland. You can learn more about it here=> In relation to estrogen dominance, when men have a higher ratio of estrogen to testosterone in their blood, often their body converts some of the testosterone to dihydrotestosterone (DHT). DHT is highly inflammatory. This inflammation can lead to BPH or in severe cases, prostate cancer. To remedy the high levels of estrogen and reverse the effects of estrogen dominance, I would advise trying Estro Clear=> . If you would like to discuss this in further detail please feel free to get in touch with our team via [email protected]

  3. alan

    Please call
    Alan James DDS

    • Ben Ong

      Hi Alan, could you please call our support team on our toll free number +1 888-868-3554 and provide more information on the subject. Wishing you good health.

  4. Jay

    What is your suggestion to help shrink the prostate>
    Looking for an answer asap. Thanks Jay

    • Ben Ong

      Hi Jay, we advise a healthy diet, exercise, and high quality supplements. Total Health for the Prostate works to naturally reduce the symptoms of BPH. It contains 23 naturally powerful ingredients which work to improve your prostate health. You can learn more about it here
      If you would like to discuss this in further detail please get in touch with our support team via [email protected]. Wishing you good health.

  5. Kunal Puri

    I have used all the products you have recommended but i have not had ptoms relief in my symptoms, however on the positive side the symptoms have not deteriorated, I am considering Rezum for my enlarged prostate

    • Ben Ong

      Hi Kunal, could you please get in touch with our support team via our toll free number +1 888-868-3554 so that we can discuss this in more detail. Diet and physical activity also play a role and the keto diet has especially been show to offer a range of benefits. We have an article coming out shortly that discusses Rezum treatment so will be sure to notify you when it is published. Wishing you good health.

    • Ben Ong

      Hi Kunal, just to let you know we recently published an article on Rezum Treatment which may be of interest to you, if this is still a procedure you are considering. You can access the article here=>

  6. brad stelmach

    …… So, which is the natural way?

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