If you’ve ever looked into treatments for male pattern hair loss, you’ve probably come across the drug Propecia. Also known by the generic name finasteride, this is a popular drug that has been used for decades to effectively treat hair loss. But what about the side effects?
Propecia has been shown to improve hair growth and put a halt to hair loss in the majority of those who take it. However, if you’re like most people and you’ve done a little Google research to find out more about the drug, you may have also seen some scary stuff about potential adverse medication effects.
Like all medications, taking Propecia does come with some risk for side effects. However, there’s also a lot of misinformation available online. Let’s get into what potential side effects to look out for if you start taking this drug, and what the risk is of those side effects persisting.
For androgenic alopecia, or male-pattern baldness, Propecia is prescribed in a 1mg dose. There is also a 5mg dose of finasteride available that is sold under the brand name Proscar, but this higher dose is used to treat benign prostatic hyperplasia (BPH), a non-cancerous enlargement of the prostate. It’s important to note that the risk of side effects discussed here is associated with the smaller, 1mg dose used to treat hair loss.
In three controlled clinical trials that lasted one year and included 945 men, 1.4% of patients chose to discontinue Propecia due to adverse side effects. It is worth noting that in the placebo control group of these clinical trials, a similar percentage (1.6%) also chose to discontinue the drug due to adverse side effects.
Propecia belongs to a drug class called 5-alpha reductase inhibitors and works by effectively blocking DHT. This hormone is responsible for male-pattern baldness. For example, the reason some people express concern about creatine causing hair loss is that this performance enhancer may elevate levels of DHT. Propecia is well tolerated by most people. However, since it works by impacting male hormone levels, the side effects most commonly experienced present as one of several sexual dysfunctions.
In the same clinical trials, 1.3% of the participants given Propecia reported experiencing erectile dysfunction, while 0.7% of the placebo group reported the same. Erectile dysfunction refers to the inability to get or maintain an erection firm enough to have sex.
The trials found that 1.3% of participants reported decreased libido, as compared to 1.3% of the control group.
Ejaculation disorder was experienced in 1.2% of trial participants and 0.7% of the control group that took a placebo. For 0.8% of the trial group and 0.4% of the control group, this sexual dysfunction was experienced as a decreased volume of ejaculate. Ejaculation disorder broadly refers to the inability to efficiently ejaculate at the moment of sexual climax. In addition to decreased volume of ejaculate, the other kinds of ejaculation disorder are premature ejaculation, delayed ejaculation, no ejaculation at all, or retrograde ejaculation where semen enters the bladder rather than emerging through the penis.
During treatment, 3.8% of the 945 trial participants experienced one or more of these side effects, while the same was true of 2.1% of those treated with a placebo. However, the side effects were resolved in those who discontinued taking Propecia as well as in most of those who kept taking the drug despite experiencing some side effects.
By the fifth year of treatment, the incidence of each of the adverse side effects was reduced to 0.3%, suggesting that the side effects aren’t permanent even in many of those who continue taking the drug, and that normal sexual function resumes in most after some time.
A different 2017 study found that while side effects are not permanent, there can be persistent sexual side effects for a considerable amount of time after ceasing to take the medication. For example, 1.4% of participants reported that their sexual dysfunction continued for at least 90 days after concluding the treatment.
If you’re experiencing side effects from taking Propecia, talk to your health care practitioner. The next course of action will depend on the severity of your side effects, and you may not necessarily have to stop taking the medication.
Your health care practitioner may advise you to keep taking the drug if your symptoms are very mild and not interfering with your quality of life, as they may resolve themselves with use. Alternatively, they may reduce your dosage or recommend that you stop taking Propecia.
Propecia works by inhibiting the effects of DHT on your hair follicles. In those who are genetically predisposed to be sensitive to DHT, the hormone leads to the gradual minimization of hair follicles. As hair follicles get smaller, the hair that grows through me becomes finer and ultimately falls out.
Since this drug blocks the effects of DHT, when you stop taking finasteride, the normal effects of the hormone resume. This means that if you stop taking your dose, your receding hairline will resume thinning as it did before you started taking the drug.
The best way to deal with Propecia side effects will depend on the specific side effects you experience and how severe they are. After getting professional medical advice, you may choose to continue with your dose, stop taking the drug altogether, or switch to a different dose.
While 1mg is the standard dose and is well tolerated by most people who take it, it is possible to take a lower dose. A 1999 study in the Journal of the American Academy of Dermatology found that even at much lower doses such as 0.2mg per day, serum DHT levels in the scalp were reduced. The study didn’t measure hair growth directly, but the reduced DHT levels suggest a lower dose may still be effective.
Alternatively, you may discuss using finasteride administered topically instead of taking Propecia tablets with your healthcare practitioner. The risk of adverse effects of topical finasteride may be lower than with the oral version of the drug, but the studies that come to this conclusion are very small.
While there’s no way to know for sure in advance if you’ll experience side effects from taking Propecia, make sure to follow the instructions of your healthcare professional when taking it. If you miss a dose, just get back on track the following day when you remember. Doubling up your dose won’t improve your results, and can increase your risk of adverse effects.
It’s normal to have questions before taking a new drug. Here are some of the most common questions people have about Propecia and its potential side effects.
Large-scale studies have not found Propecia side effects to be permanent. There are anecdotal examples of people experiencing persistent sexual dysfunction even after taking the drug, and some small studies that find this as well. However, the large, well-designed studies used by regulators like Health Canada and the FDA do not report permanent side effects.
It’s worth noting that Propecia has been used safely by many patients since 1997 to prevent hair loss and improve hair growth.
For most people who experience side effects from Propecia, the effects resolve after discontinuation of the drug. Even for those who continue taking the medication, many see a reduction in side effects over time.
In many who experience side effects, no longer taking the drug reverses the side effects. This is also true for those who tolerate the side effects for a while as they continue to take the drug. If you experience side effects, discuss them with your healthcare provider to decide on the best course of action for your specific situation.
The side effects of Propecia may go away on their own after taking the drug for some time, or you may choose to discontinue the drug. It’s possible to experience persistent sexual side effects for some time even after the drug is no longer being taken, but in the majority of people, they do go away.
Clinical trials found that 1.3% of those who took Propecia for hair loss experienced some form of erectile dysfunction. It’s worth noting that 0.7% of the control placebo group also experienced erectile dysfunction.
There isn’t evidence that finasteride causes shrinkage, or reduction in penis size, in humans. A higher dose of finasteride which is 5 times the amount used to treat hair loss is used to treat prostate enlargement in some cases, but this does not mean it also reduces penis size.
The views expressed here are those of the author and, as with the rest of the content on Health Guide, are not a substitute for professional medical advice, diagnosis, or treatment. If you have any medical questions or concerns, please talk to your healthcare practitioner.