Q: What do I do if I start experiencing side effects on finasteride? — L.L. ~ Riverdale, N.Y.
A: Don’t panic, just stop the medication and let your doctor know. He or she will give you guidance based on your symptoms.
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Recent news reports, coupled with warnings from Merck and the FDA, about Propecia’s possible persistent sexual side effects have caused growing concern about this popular hair loss treatment. An increasing number of men now fear that Propecia (finasteride 1mg) will cause permanent sexual dysfunction.
Merck’s and the FDA’s warning, however, was based on a small number of random self-reports, not on empirical studies that showed a cause and effect relationship between finasteride and sexual dysfunction. There are two possible reasons that existing studies have not found a significant relationship between finasteride use and persistent sexual dysfunction: 1) the effect of finasteride on sexual function is too small to significantly measure in any one study, or 2) finasteride has no significant negative effect on sexual function.
To address the first possibility, Aditya K Gupta and Andrew Charrette ((Gupta AK, Charrette A. The efficacy and safety of 5α-reductase inhibitors in androgenetic alopecia: a network meta-analysis and benefit-risk assessment of finasteride and dutasteride. J Dermatolog Treat. 2014;25(2):156-61.)) at the University of Toronto recently conducted a large scale meta-analysis across 16 controlled studies, studies designed to test the efficacy of finasteride, to see if a significant number of patients in those studies reported persistent sexual side effects. The rationale of a meta-analysis is that if there is an effect (of finasteride on sexual function) that is too small to measure in any one particular study, then it may be possible to detect the effect if one pools data from many different studies.
Gupta and Charrette analyzed the results of 16 studies that compared various doses of finasteride against a placebo and found that finasteride consistently proved effective in stopping or slowing hair loss. They also found that the number of self-reported cases of persistent sexual dysfunction by patients given finasteride was statistically no different from the number reported by patients given a placebo.
In other words, they found that finasteride was no more likely to cause persistent sexual dysfunction than a placebo.
This study supports the conclusion of existing literature that there is no correlation between finasteride use and persistent or permanent sexual dysfunction. That said, this is an important issue that still needs to be studied.
Posted byQ: I’ve heard that FDA added a description of reports of male infertility to the side effect labels of both Propecia and Proscar (finasteride). Is this a likely side effect in your experience? — S.S., Rolling Hills, California
A: Propecia (finasteride 1mg) may lead to male infertility not only by changing the consistency of the male ejaculate but by decreasing the sperm count as well, but this is uncommon.
Ejaculate is a combination of sperm produced by the testes and a viscous fluid made by the prostate. Since finasteride shrinks the prostate, it can make the ejaculate less viscous (more watery).
Most patients trying to conceive will have no issues while taking Propecia.
If one is having difficulty trying to conceive for 4-6 months, then it is reasonable to stop taking Propecia.
It is important to know that taking Propecia while trying to conceive will not lead to congenital deformities or issues with the fetus as long as the woman does not come in direct contact with the medication.
Posted byQ: As a Propecia user, I was alarmed when I read headlines last year about a new study indicating very high rates of depression and erectile dysfunction caused by Propecia, with symptoms persisting even after the drug was stopped. However, when I read the articles, this “study” appeared to be survey of 61 men who had taken Propecia and already reported sexual problems who were then asked about symptoms of depression. These rates of depression were compared to a small survey of men who had hair loss but had never taken Propecia.
Anyone with a basic understanding of statistics would know such a survey was deeply flawed. First, it is a textbook example of a bad data sample — to get sound results you have to start with an unbiased and random group of people who took the drug, not a self-selected group of men already suffering symptoms. The study also confuses correlation with causation — because these men are suffering from ED or depression does not necessarily mean it was caused by the drug. Am I missing something here, or did the media just report these “findings” with no scrutiny on what was actually studied? — Jonathan, Brooklyn, NY
A: Jonathan, I think you’re right on the mark. The way the study was conducted raises a lot of concern about the accuracy of the findings. It is really important that additional data is obtained in a controlled way, as this will be most useful for physicians in advising patients. I addressed concern on these reports last year. The issue of persistent sexual dysfunction as a side-effect of finasteride (Post-Finasteride Syndrome) is an on-going issue that we take very seriously. I sit on the International Society of Hair Restoration Surgery (ISHRS) Task Force on Finasteride Adverse Events, so this is an issue that we watch very closely.
Posted byQ: Dr. Bernstein, I am an attending at Mass General Hospital in Boston and would like to ask you regarding your experiences using finasteride for male androgenetic alopecia. While I have not noticed any side effects in the patients that I have been treating, I increasingly get questions regarding side effects based on the recent media attention to reports of potentially permanent problems regarding libido or erectile dysfunction. I know that in the literature there is a slight increase of reversible sexual dysfunction (~4% vs. ~2% in placebo) with Propecia, and no convincing evidence to date in the medical literature that have used controlled studies regarding permanent problems even after discontinuing Propecia. — S.Z., Boston, Massachusetts
A: That is correct.
Q: I know that you have treated many patients over a long period of time, and I was thus wondering what your take is on potentially permanent sexual dysfunction after taking finasteride. Have you seen any convincing reports/patients or do you have any concerns regarding irreversible side effects?
A: I have seen 5 cases in over 10,000 patients on finasteride that complained of this but, of course, there is no way to know for sure if there is a cause and effect relationship. As you know, real side effects may be followed by psychological ones and if the sexual dysfunction has another cause, then stopping finasteride would have no effect on the symptoms. The incidence of intermittent or persistent sexual dysfunction in the general population of men is about 30%, so one would expect these numbers to be much higher just due to the normal incidence. It is really a difficult situation to understand. The experience that my colleagues and I have in our practices is much different than one would expect after reading the numerous anecdotal reports on the internet.
Q: Would you think it is safe to say that any potential sexual dysfunction is reversible after discontinuing the use of finasteride?
A: I don’t think that anyone knows at this point. The FDA is coming down on the side of caution and saying that it is possible, although it is not based on any new studies. If the phenomenon is real, the possible mechanism is not yet known.
Q: In the relatively few patients that I have treated with Propecia, they did not even report temporary problems regarding libido or erectile dysfunction. Do you think they are real or rather attributed to Propecia simply because the patient is made aware of these potential side effects?
A: I think that psychological effects may account for many cases. At this time, it is still not clear if a physiologic “post-finasteride syndrome” is real. A lot more work needs to be done before we have a definitive answer to this question.
Posted byThe central finding of a 2004 study led by Italian researcher Dr. Antonella Tosti, in which he and his team investigated sexual dysfunction in hair loss patients being treated for androgenetic alopecia, was that there was no statistically significant change in sexual function after four to six months of treatment with finasteride 1mg (Propecia).
The researchers used a questionnaire, called the abridged 5-item version of the International Index of Erectile Function (IIEF-5), to measure sexual function in the men in the study. The questionnaire, which is considered an internationally valid diagnostic tool for distinguishing between men with and without erectile dysfunction, asks the patients 15 questions on the topics of: erectile function, orgasmic function, sexual desire, intercourse satisfaction, and overall sexual satisfaction. By administering the questionnaire both before and after treatment with finasteride, the researchers were able to determine if sexual function was impaired by the treatment.
The result of this investigation in the sexual function of 186 patients was that, “the erectile function of all patients remained stable after 4 to 6 months of treatment with finasteride 1 mg.”
Interestingly, the research team found that sexual side effects were actually less common than reported in the clinical trials of the drug. They suggest that this difference was potentially due to the fact that subjects in the clinical trials were made aware of the potential for sexual side effects, and were asked about these side effects upon each visit, which led to higher reporting of side effects than what would otherwise be the case.
Reference:
Tosti A, Pazzaglia M, Soli M, Rossi A, Rebora A, Atzori L, Barbareschi M, Benci M, Voudouris S, Vena GA. Evaluation of Sexual Function With an International Index of Erectile Function in Subjects Taking Finasteride for Androgenetic Alopecia. Arch Dermatol. 2004;140:857-858.
Download the Tosti study of erectile function and finasteride 
Q: You prescribed Propecia for my hair loss. I was wondering if the news report on Propecia side effects has altered your opinion regarding the safety of this drug? — N.D., Belle Meade, Tennessee
A: It has not changed. I believe you are referring to Dr. Michael Irwig’s study at George Washington University published in the Journal of Sexual Medicine. I was already aware of the study when I prescribed the medication for you and we discussed the risk of persistent side effects at your consult.
Although all types of data should be considered, it is important to realize that this was not a scientific study, but a survey. It had very significant selection bias. From this type of study, one can’t prove cause and effect relationships or even get a sense of actual incidences. These were patients who were recruited because they already had persistent sexual dysfunction. Since it is not clear if their persistent problems were directly due to the medication or from other factors, and since these patients were selected, rather than randomly assigned, the additional information can be gained from the report is very limited.
That said, the reporting of persistent side effects should not be taken lightly, but should be viewed in the context of all available data. It is extremely important for us to continue to be vigilant, as this is a very significant issue, but it is equally important not to make decisions on data sensationalized in the media. As a result of the finasteride data, some are presenting surgery as a more reasonable alternative than medication. For a young person, that is usually not the case.
Posted byOn April 11, 2012, the U.S. Food and Drug Administration (FDA) announced changes to the professional labels for Propecia (finasteride 1 mg) and Proscar (finasteride 5 mg) to expand the list of sexual adverse events reported to FDA as some of these events have been reported to continue after the drug is no longer being used (note that erectile dysfunction after stopping use of these drugs was added as a known event in 2011). The new label changes include:
- A revision to the Propecia label to include libido disorders, ejaculation disorders, and orgasm disorders that continued after discontinuation of the drug.
- A revision to the Proscar label to include decreased libido that continued after discontinuation of the drug.
- A revision to both the Propecia and Proscar labels to include a description of reports of male infertility and/or poor semen quality that normalized or improved after drug discontinuation.
Despite the fact that clear causal links between finasteride (Propecia and Proscar) and sexual adverse events have NOT been established, the cases suggest a broader range of adverse effects than previously reported in patients taking these drugs.
Propecia
Only a small percentage of men using these drugs have experienced a sexual adverse event. During treatment with Propecia, 3.8% of men had reported one or more adverse sexual experiences as compared to 2.1% men who did not receive Propecia (received placebo). This represents a 1.7% difference.
For Propecia, the FDA’s Agency’s Adverse Events Reporting System (AERS) database between 1998 and 2011 found 59 cases of reported sexual dysfunction that lasted for at least three months following discontinuation of Propecia, and included erectile dysfunction, decreased libido, problems with ejaculation and orgasm disorders.
The FDA has not established a cause and effect relationship between finasteride and the sexual adverse events that continued after stopping drug use. The FDA believes that finasteride remains a safe and effective drug for its approved indications. Healthcare professionals and patients should consider this new label information when deciding the best treatment option.
For more information, read this PDF document: Questions and Answers: Finasteride Label Changes.
Posted byQ: I am 27 years old and I have been on Propecia for 12 months now. Honestly, I have seen no response from it. In my dermatologist’s opinion I am a non-responder. I asked about Avodart and he said, since Propecia didn’t help then Avodart won’t help as well since both are DHT blockers, and if one didn’t work the other won’t either. In your opinion do you think Avodart is better? I have read that it blocks more DHT than Propecia. What is the dosing for Avodart? If someone does not respond to Propecia will they also not respond to Avodart? — A.C., West University Place, Texas
A: Avodart (dutasteride) is more effective than Propecia (finasteride) and some patients will respond to dutasteride who do not respond to finasteride. Dutasteride decreases serum DHT about 90% compared to 70% for finasteride. The usual starting dose of Avodart is 0.5mg a day.
That said, dutasteride is not FDA approved for use in hair loss and if a person has sexual side effects, the side effects are more likely to be persistent after stopping the medication compared to finasteride.
Read more about Avodart (dutasteride)
Read more about Propecia (finasteride)
Posted byIn response to anecdotal evidence of sexual side effects continuing after stopping Propecia (finasteride 1mg), the International Society of Hair Restoration Surgery (ISHRS) has published a press release for the hair restoration community about the safety and efficacy of the drug.
The release notes that scientific data gathered from extensive testing finds no correlation between persistent sexual dysfunction and Propecia:
The ISHRS reports that there is no evidence-based data substantiating the link between finasteride and persistent sexual side effects after discontinued use of the drug in numerous, double blinded, placebo controlled studies conducted evaluating the use of Propecia 1mg for hair loss.
The ISHRS statement also touches on the fact that the exact cause of sexual dysfunction can be difficult to diagnose:
Sexual dysfunction is a complex disorder, and Dr. Martinick noted that it often can be hard to pinpoint the exact cause – particularly when multiple factors such as nicotine, alcohol, prescription medications, stress, anxiety, fatigue and depression can contribute to erectile dysfunction (ED).
In the interest of hair loss patients around the world, the ISHRS has formed a task force to examine the anecdotal reports of persistent sexual dysfunction by Propecia users. It has also called on medical communities from a variety of disciplines — dermatologists, hair loss physicians, urologists, endocrinologists and sexual medicine specialists — to share data and experiences.
Visit our section on Propecia to learn more about the medication, its use, and side effects.
Read the full ISHRS press release here.
Posted byQ: I heard that the sexual side effects of Propecia are irreversible. Is this true? — L.R., Parsippany, NJ
A: The sexual side effects of finasteride (Propecia) begin to subside soon after the medication is discontinued. This would make sense since the drug finasteride is a reversible inhibitor of DHT. Although it is possible for side effects to be persistent after stopping the medication, this situation seems to be very uncommon and a cause and effect relationship is still in question.
One should consider that sexual dysfunction is relatively common in the adult male population and millions of patients take finasteride. Thus, there is a likely probability that some patients on finasteride may experience sexual dysfunction unrelated to the medication and, therefore, when the medication is stopped, the side effects would not be expected to go away.
Another thing to consider is that once a patient experiences sexual dysfunction (from a medication or another reason) psychological factors may come into play that make the side effects persist, even though they are unrelated to the medication or other underlying cause that may now be gone.
It is important to keep in mind that medication plays an important role in the prevention and treatment of androgenetic alopecia and decisions to use medications should be done thoughtfully and in an informed way. Blog postings can offer some subjective information, but they do not constitute true research and should be used in conjunction with the information provided by your physician and other informed sources.
Learn more about Propecia (finasteride) and other hair loss medication.
Posted byQ: I started using both Propecia (finasteride) and Rogaine for roughly the past 15 weeks. In the last month I’ve been experiencing pain in my left testicle area. At first I thought this may be due to Varicocele; however, after some quick internet searches I thought it may also be the Propecia. The pain doesn’t seem to be in the testicle itself as much as the surrounding veins on the left side. What should I do? — B.L., Houston, TX
A: Your symptoms are the classic ones of a varicocele, namely pain on the left side that is adjacent to the testicle. Symptoms of finasteride would more likely be bilateral, although the discomfort does not need to be in the testicle itself. If your symptoms are worse at the end of the day when you have been standing, and less in the AM when you first arise, these suggest a varicocele.
In your pain is consistently worse towards the end of the day, I would see a urologist, as surgical intervention might be warranted, particularly if it is affecting sperm counts – which should be checked as part of the evaluation.
If this is not the case, then stop finasteride for a least a month and see if the symptoms subside. If they do go away off finasteride, I would not take the medication again. If the symptoms persist off finasteride, I would still see a urologist.
Read more about Propecia in our section on hair loss medications.
Posted byQ: I’ve now been taking finasteride for just over 5 months. I have noticed that my semen quality has changed just in the last 3 months, and it seems now much less in quantity and is quite watery and clear in color. I think the current problems are due to the finasteride, what do you think? — S.F., Rolling Hills, California
A: Finasteride, the active drug in Propecia, can change the quality of the semen, since it is decreasing the component of seminal fluid that is secreted by the prostate. You may want to consider having your sperm counts checked, as finasteride can lower this. If the symptoms are not bothering you, and your sperm counts are normal, it should be OK to continue the medication. If you were having difficulty conceiving, then I would stop the medication.
Posted byQ: I heard that there is a new drug on the market called Avodart for prostate enlargement which might help with hair loss as it blocks the conversion of testosterone to DHT better than Finasteride and is more effective than Propecia. Do you recommend taking it and if so what is the dose? — Y.B., Orlando, Florida
A: I am currently not recommending that patients take Dutasteride for hair loss, although it is more effective than Propecia, finasteride 1mg. (Dutasteride 0.5, the dose generally used for hair loss, seems to be slightly more effective than finasteride 5m in reversing miniaturization.)
The reasons that I am hesitant to prescribe it at present are outlined in the Hair Restoration Answers question, “Is Avodart Safe?”
In addition to the reasons that I listed in that response, I would also consider that: Dutasteride, unlike finasteride, decreases sperm counts, it can result in persistent decreased sex drive and the incidence is greater than with finasteride. Finally there are a significant number of alpha-type 1 receptors in brain, those affected by dutasteride, but not finasteride.
However, since Dutasteride is approved for older men with prostatic disease, using it for hair loss in this age group (usually in a lower dose) is reasonable.
Posted byQ: My friend is taking Avodart, he bought it over the internet. Is it safe to take? — T.G., Denver, Colorado
A: Avodart (dutasteride 0.5mg) was approved by the FDA for the treatment of prostate enlargement in men in 2002. Avodart has not been approved for the treatment of androgenetic hair loss, although physicians can use an approved medication in ways other than for which it was specifically approved. That said, the use of dutasteride certainly requires a doctor’s supervision.
Like finasteride (the active ingredient in Proscar and Propecia), dutasteride blocks the enzyme 5-alpha reductase that converts testosterone to DHT (DHT is a key hormone that causes hair loss). However, unlike finasteride, which only inhibits the Type I form of the enzyme, dutasteride inhibits both the Type I and Type II forms. This combined effect lowers circulating DHT more with dutasteride than with finasteride, but also increases the incidence of its side effects.
The Type II form of the enzyme (blocked by finasteride) is found predominantly in the hair follicle. The Type I form of the enzyme has been found in the scalp and sebaceous glands, and many other parts of the body, but its exact role in hair growth has not been determined. It is felt that dutasteride’s ability to dramatically lower serum levels of DHT is what makes it a more potent medication in hair loss.
When considering the safety of dutasteride, one should consider the following:
- It acts on other parts of the body besides the hair follicle.
- Unlike finasteride, where families that had a deficiency of the Type II 5-alpha reductase enzyme were followed for years without any adverse effects, there is no natural biologic model to show the safety of dutasteride.
- Dutasteride has been approved for prostate enlargement in an older male population. It is not approved for hair loss and, in fact, the clinical trials for hair loss were discontinued, so there is no safety data for its use in younger patients. There is a greater incidence of sexual side effects with dutasteride compared to finasteride.
- The 1/2 life of dutasteride is 5 weeks compared to 6-8 hours for finasteride. Serum concentrations of dutasteride are detectable up to 4-6 months after discontinuation of treatment.
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