What is finasteride?
Finasteride is a medication used for male pattern hair loss. It slows down hair loss and may even help grow back some hair. When used for this reason, the typical dose of finasteride is 1 mg (1 tablet) daily. It’s known by the brand name Propecia.
Finasteride works by blocking the enzyme responsible for converting testosterone to dihydrotestosterone (DHT). DHT is a hormone metabolite that causes hair follicles to become smaller. By shutting down DHT, hair follicles can work more normally and grow full healthy hair.
What is tadalafil?
Tadalafil (brand name Cialis) is a prescription medication for erectile dysfunction. Tadalafil makes it easier to achieve and maintain an erection. This medication works by relaxing blood vessels so that when you are aroused, blood can flow into the penis easily to achieve an erection.
There are two options for using tadalafil:
- Taking a 10 to 20 mg dose on-demand ½ to 2 hours before sexual activity, or
- Taking a 2.5 to 5 mg daily dose every day
Why would I take tadalafil and finasteride together?
There are a few reasons why your doctor may recommend both tadalafil and finasteride for you.
First, both hair loss and erectile dysfunction are common concerns for men of all ages, but especially as you get older. To deal with both concerns, your doctor may offer you two prescriptions: finasteride for hair loss, and tadalafil for erectile dysfunction.
Second, a rare side effect of using finasteride for hair loss is developing erectile dysfunction. If you want to continue taking finasteride and benefiting from it, you may choose to add on tadalafil to deal with the side effects.
Does finasteride cause erectile dysfunction as a side effect?
When using finasteride for hair loss, erectile dysfunction was reported as a side effect in some studies but not others. Some studies reported that finasteride was associated with sexual side effects, such as decreased libido, difficulty achieving and maintaining an erection, and decreased semen production. However, other studies did not find any correlation between taking finasteride 1 mg/day and erectile dysfunction.
In all cases, sexual side effects were not common. Researchers also found that these side effects may improve with time even with no treatment.
What should I do if I am having sexual side effects from taking finasteride for hair loss?
Start by discussing your symptoms with your doctor. Your healthcare provider is the best person to help you figure out what’s going on. Changes in how you feel sexually could be a side effect from finasteride, a side effect of another medication, a new health concern, or a complication of another health condition.
If you do find that finasteride is the most likely culprit for your symptoms, your doctor can help you decide what to do next. A few options to consider are:
- Continue using finasteride and see if your symptoms get better by themselves
- Stop finasteride and try another hair loss treatment
- Add on a medication for erectile dysfunction like tadalafil
Does tadalafil work for erectile dysfunction?
Yes, tadalafil is effective as a treatment for erectile dysfunction. In studies of men with sexual side effects from finasteride, adding on tadalafil improved symptoms of erectile dysfunction.
Is it safe to take tadalafil and finasteride together?
Clinical trials have been conducted with the combination of tadalafil and finasteride, typically in men who use this combination for enlarged prostate.2 In these studies, the combination of these 2 medications was tolerated well. Patients often had fewer sexual side effects compared to taking finasteride alone, and had no greater side effects compared to tadalafil by itself. If you are prescribed both as once-daily medications, they can be taken together at the same time or at different times.
In summary, taking finasteride and tadalafil is generally a safe and effective combination for treating hair loss and erectile dysfunction. As with all medications, checking with your healthcare provider is important to ensure it is a good idea for your specific health situation.
1Shin YS, Karna KK, Choi BR, Park JK. Finasteride and Erectile Dysfunction in Patients with Benign Prostatic Hyperplasia or Male Androgenetic Alopecia. World J Mens Health. 2019 May;37(2):157-165. doi: 10.5534/wjmh.180029. Epub 2018 Aug 10. PMID: 30209896; PMCID: PMC6479090.
2Olesovsky C, Kapoor A. Evidence for the efficacy and safety of tadalafil and finasteride in combination for the treatment of lower urinary tract symptoms and erectile dysfunction in men with benign prostatic hyperplasia. Ther Adv Urol. 2016 Aug;8(4):257-271. doi: 10.1177/1756287216650132. Epub 2016 May 26. PMID: 27928428; PMCID: PMC5131741.