Finasteride Side Effects: What Does the Latest Research Say?
- Finasteride is a medication commonly used to treat hair loss in men.
- There are a number of side effects associated with this medication, although new studies suggest these side effects may not be as severe as the media reports.
- While most people can safely use finasteride, it is important to talk to your doctor about the risks involved.
Finasteride is an oral medication sold under the brand names Proscar and Propecia. While it was originally created by Merck pharmaceutical company to treat enlarged prostate glands, today it is more commonly used to prevent hair loss in men.
A large number of men around the world have successfully used Propecia to stop hair loss and promote the growth of new hair. The safety of Propecia, however, is a matter of some debate.
In recent years, a number of mainstream media outlets have reported that it is closely associated with a variety of negative side effects, including sexual dysfunction and cognitive impairment, and may increase the risk of some specific types of cancer.
Is there any truth to these claims? We have rounded up the information you will need to make an informed decision
What is finasteride?
Finasteride is one of two FDA-approved hair loss drugs (along with minoxidil, a topical liquid solution commonly sold under the brand name Rogaine). It is the first medication in history to successfully treat most cases of male pattern baldness.
A number of clinical trials have shown that finasteride can do wonders for helping maintain a full head of hair. A five-year, placebo-controlled study found about 90% of men who used finasteride were able to stop hair loss or visibly improve scalp coverage, as noted in a report published in the Journal of Investigative Dermatology Symposium Proceedings. In comparison, about three in four men who were treated with a placebo sustained visible hair loss.
Finasteride’s ability to stimulate hair growth and stop hair loss is due to how it interacts with 5-alpha reductase (5-AR), an enzyme that converts testosterone into dihydrotestosterone (DHT). DHT is the hormone that is largely responsible for causing genetic pattern baldness. Finasteride inhibits the effectiveness of 5-AR, thereby reducing the body’s ability to produce DHT and minimizing the risk of hair loss.
How to use finasteride
Finasteride is a prescription drug that is available in tablet form. As with any medication, dosage may vary slightly depending on your specific needs—talk to your doctor or pharmacist before starting treatment.
For hair loss
Most doctors recommend taking finasteride at the same time every day, with or without food. If you are taking finasteride to treat male pattern baldness, your doctor may recommend taking 1 mg per day.
Depending on your hair growth cycle, it may take three months or longer before you start to see the effects. If you use finasteride without seeing any improvements, talk to your healthcare professional about whether you should continue treatment.
Finasteride is predominantly prescribed to men, but occasionally it may be used to treat hair loss in women. However, women who are pregnant or may become pregnant in the near future should not take finasteride as trace amounts of the drug can potentially lead to birth defects.
For an enlarged prostate
If you are using finasteride to treat benign prostatic hyperplasia (BPH)—an enlarged prostate gland—your doctor may advise you to take 5 mg per day. The treatment process is slow, and it may take six months before your symptoms begin to improve.
Keep in mind that although finasteride can help reduce the severity of your symptoms, it cannot cure BPH.
Regardless of your reason for taking finasteride, if you miss a dose, do not take a double dose to compensate—just resume your regular dosing schedule the next day.
Finasteride side effects
As with many medications on the market, Propecia carries some potential side effects that may affect your decision to use it.
As mentioned previously, a large number of mainstream media outlets have reported extensively on the side effects of finasteride. This has created much controversy over the use of the drug.
While there is some basis to these fears, the truth is that in many cases the risks have been blown out of proportion and the vast majority of people are able to use finasteride with no adverse effects. The following is what current research states about some of the side effects associated with Propecia.
There’s a healthy body of research indicating Propecia may be associated with a range of sexual dysfunctions, including:
- erectile dysfunction
- low libido
- decreased volume of ejaculate
- pain in the testicles
However, despite widespread reporting on the issue, these sexual side effects are relatively rare. About 2.1–3.8% of patients who use finasteride experience one of these adverse sexual side effects, according to a comprehensive review of clinical trials from the Venkat Charmalaya – Centre for Advanced Dermatology.
Erectile dysfunction is the most common, followed by ejaculatory dysfunction and low sex drive. However, these dysfunctions tend to occur only during the initial stages of treatment and resolve as the body adjusts to the drug’s effects.
According to Dr. Alan Bauman of Bauman Medical in Boca Raton, FL “Sexual side effects, such as decreased libido or mild erectile dysfunction can occur in about 2% of men who take finasteride 1mg daily. Since finasteride is cleared completely from the body in about a week, stopping the medication if you have side effects results in restoration of sexual desire and functioning.”
These sentiments are echoed in a seven-year study of more than 17,000 patients enrolled in a Prostate Cancer Prevention Trial published in the Journal of the National Cancer Institute.
Researchers found that finasteride increased sexual dysfunction “only slightly,” and this side effect diminished over time. Investigators concluded that “The effect of finasteride on sexual functioning is minimal for most men and should not impact the decision to prescribe or take finasteride.”
For most people, these effects are temporary and tend to resolve over time, although there have been reports that some patients continue to experience persistent sexual problems even after they stop taking finasteride.
However, as noted in research by Weill Cornell Medical College, current studies on this side effect are significantly flawed, and more high quality clinical trials are needed to fully understand the link between finasteride and long-term adverse sexual side effects.
Increased risk of cancer
There are a number of reports that suggest the use of finasteride can increase the risk of specific types of cancer.
In a study published in the New England Journal of Medicine, investigators found that while finasteride reduced the risk of prostate cancer by about one third, it was also associated with an increased risk of high-grade cancer (cancer cells that grow and spread more quickly than their low-grade counterparts).
It is important to note this does not necessarily mean finasteride actually causes cancer. In a follow-up study, researchers explained the increased risk factor was due to finasteride’s ability to disguise the appearance of prostate cancer—enabling the cancer to develop to a more advanced stage before it could be identified.
As noted in a study published in the Journal of Cutaneous and Aesthetic Surgery, there are also some isolated reports of finasteride increasing the risk of male breast cancer. However, no clear causal link has been established, and more research is needed to understand how finasteride may affect the risk of developing this cancer.
Mental side effects
Many people report feeling long-term mental fog when they initially start using finasteride. This can make it difficult to focus on the task at hand and may also impact memory.
Finasteride is also linked with depressive symptoms. In recent years, government agencies around the world, including in the United States, have updated the product labeling of finasteride to include depression as a possible side effect—and one that may persist even after discontinuing treatment.
A small study published in the Journal of Clinical Psychiatry found 75% of former finasteride users exhibited depressive symptoms, compared to just 10% of the control group who had never used finasteride.
The exact cause of the link between finasteride and depression is still a topic of some discussion, but research from University Hospital Stavanger suggests it might have something to do with the way finasteride inhibits hippocampal neurogenesis—a process that involves the ongoing generation of neurons in the hippocampus (a small organ within the brain associated with memory and spatial navigation).
Other side effects
You may experience a range of other side effects including:
- swelling, lumps, or pains in the breasts
- difficulty breathing
- swelling of the face, hands or feet
If you experience any of these symptoms, call your doctor or dermatologist immediately.
Are the risks worth it?
As noted, the dangers involved with finasteride are not quite as severe as the mainstream media would have you believe. Nevertheless, there are a number of significant risks to be aware of, including potential sexual side effects, cognitive impairment, depression and more, which may influence your decision to pursue this type of treatment.
Whether or not finasteride is right for you depends on your own unique circumstances, how your condition has responded to other forms of treatment and what level of risk you are comfortable with.
Talk to your doctor to discuss your options and find out if finasteride is right for you.
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