Finasteride Erectile Dysfunction: Causes & Solutions

Finasteride and Erectile Dysfunction: What You Need to Know

Published: 14 October 2026

Finasteride erectile dysfunction is a recognised side effect that concerns many men taking this medicine for hair loss or prostate enlargement. While not everyone experiences it, understanding the link, how common it is, and what you can do about it is important for making informed decisions about your treatment. This page explains the connection between finasteride and erection problems, when to seek help, and the options available if you're affected.

Does Finasteride Cause Erectile Dysfunction?

Finasteride can cause erectile dysfunction in some men. The medicine works by blocking an enzyme called 5-alpha-reductase, which converts testosterone into dihydrotestosterone (DHT). While this mechanism helps slow hair loss and shrink an enlarged prostate, it can also affect sexual function in a minority of users [2].

Clinical trials show that erectile dysfunction occurs in approximately 1–2% of men taking finasteride for hair loss (1mg daily) and slightly more frequently in those taking higher doses (5mg daily) for benign prostatic hyperplasia. Most men tolerate finasteride well without any sexual side effects, but it's important to be aware of the possibility [12].

The good news is that for many men who do experience this side effect, erectile function improves after stopping the medicine or even while continuing treatment. However, you should never stop a prescribed medicine without first discussing it with your doctor or prescriber, as they need to weigh the benefits of your treatment against any side effects you're experiencing.

How Common Is Finasteride Erectile Dysfunction?

The reported frequency of erectile dysfunction with finasteride varies depending on the dose and the study. In clinical trials of finasteride 1mg (used for male pattern hair loss), erectile dysfunction was reported in around 1.3% of men compared to 0.7% taking placebo. For finasteride 5mg (used for prostate enlargement), rates were slightly higher, affecting approximately 2–8% of users [12].

It's worth noting that erectile dysfunction is also common in the general population, particularly as men age, and can be caused by many factors including stress, anxiety, cardiovascular disease, diabetes, and other medications [1][2]. This means that not all erection problems in men taking finasteride are necessarily caused by the medicine itself.

Some men report that sexual side effects improve over time, even while continuing finasteride. In clinical trials, many men who initially experienced erectile dysfunction found that symptoms resolved during continued treatment. However, a small number of men report persistent symptoms even after stopping the medicine, though this remains an area of ongoing research and debate [12].

Other Sexual Side Effects of Finasteride

Alongside erectile dysfunction, finasteride can occasionally cause reduced libido (sex drive) and ejaculation disorders, such as reduced ejaculate volume. These side effects are reported at similar frequencies to erectile dysfunction and may occur together or separately. If you experience any changes to your sexual function while taking finasteride, it's important to discuss them with your prescriber rather than suffering in silence [12].

What NOT to Do If You Experience Finasteride Erectile Dysfunction

If you develop erectile dysfunction while taking finasteride, do not stop the medicine suddenly without medical advice. Your prescriber needs to review your situation, discuss whether the symptom is likely related to finasteride, and help you weigh the benefits of continuing treatment against the side effects you're experiencing.

Do not assume that erection problems are definitely caused by finasteride without proper assessment. Erectile dysfunction can have many causes, including psychological factors, cardiovascular disease, diabetes, other medications, or lifestyle factors such as smoking, excessive alcohol, or lack of exercise [1][2]. Your GP or prescriber can help identify whether finasteride is the likely cause or whether other factors need addressing.

Avoid self-medicating with erectile dysfunction tablets or other treatments without a proper consultation. While ED medicines can often be used alongside finasteride, you need a clinical assessment to ensure they're safe and appropriate for you, particularly if you have other health conditions or take other medicines. Never buy prescription medicines from unregistered sources, as they may be counterfeit, unsafe, or interact dangerously with your other treatments.

Options to Discuss With Your Prescriber

If you're experiencing erectile dysfunction while taking finasteride, several options are worth discussing with your doctor or prescriber. The right approach depends on how much the side effect is affecting your quality of life, how important the finasteride treatment is for you, and whether other factors might be contributing to the problem.

One option is to continue finasteride and see whether the symptom improves over time, as some men find their sexual function returns even while staying on the medicine. Alternatively, your prescriber might suggest a 'drug holiday'—temporarily stopping finasteride to see if erectile function improves—though this needs careful discussion, particularly if you're taking it for prostate symptoms rather than hair loss.

Another approach is to treat the erectile dysfunction itself while continuing finasteride. PDE5 inhibitor tablets such as sildenafil, tadalafil, vardenafil, or avanafil can often be prescribed alongside finasteride, as there is no major interaction between these medicines [3][4][5][6]. Your prescriber will assess your overall health, check for any contraindications, and determine the most suitable treatment if this route is appropriate for you.

When to See Your GP

If you develop new erectile dysfunction, it's important to see your GP for a full assessment, even if you're taking finasteride. Erection problems can be an early warning sign of cardiovascular disease or diabetes, so your doctor will want to check your blood pressure, blood sugar, cholesterol, and overall heart health [1][2]. Addressing these underlying factors can improve both your general health and your sexual function.

Can You Take ED Tablets With Finasteride?

Yes, erectile dysfunction tablets can usually be taken alongside finasteride. There is no significant interaction between finasteride and PDE5 inhibitors such as sildenafil (Viagra), tadalafil (Cialis), vardenafil (Levitra), or avanafil (Spedra) [3][4][5][6]. Many men successfully use both treatments together—finasteride for hair loss or prostate health, and an ED tablet to support erectile function.

However, you must have a proper consultation before starting any ED treatment. The prescriber will review your full medical history, current medications, and any health conditions to ensure a PDE5 inhibitor is safe for you. These medicines are not suitable for everyone—for example, they cannot be used if you take nitrates for angina, have severe heart problems, or have had certain eye conditions [3][4][5][6].

At Cured Pharmacy, our UK-registered prescribers review every consultation individually. If ED tablets are appropriate for you, we offer a range of licensed treatments at transparent prices, delivered discreetly to your door. All our medicines are genuine, UK-sourced, and dispensed by our GPhC-registered pharmacy (GPhC 9012511). You'll need to complete an online consultation, which a prescriber will review before approving and dispensing your treatment.

Treatment Options for Finasteride Erectile Dysfunction

If you and your prescriber decide that treating the erectile dysfunction is the right approach, several licensed medicines are available. PDE5 inhibitors are the first-line treatment for most men with ED and work by increasing blood flow to the penis during sexual stimulation [1][2]. They do not cause an automatic erection—you still need to be sexually aroused for them to work.

Sildenafil (the active ingredient in Viagra) is taken about an hour before sex and lasts for around four to six hours. Tadalafil (the active ingredient in Cialis) can be taken on-demand (working within 30 minutes and lasting up to 36 hours) or as a lower daily dose for men who prefer spontaneity. Vardenafil and avanafil are alternatives that work similarly to sildenafil but may suit some men better [3][4][5][6].

Your prescriber will help you choose the most suitable option based on your lifestyle, preferences, and medical history. At Cured Pharmacy, we stock both branded and generic versions of these medicines. Generic medicines contain the same active ingredient and work in the same way as the branded versions but are usually more affordable. All our treatments require a consultation and prescription from a UK-registered prescriber.

Non-Tablet Alternatives

If tablets are not suitable or effective for you, other options include Eroxon gel (a topical medical device available without prescription), Vitaros cream (alprostadil, applied to the urethra), or Caverject injections (alprostadil, injected into the penis). These alternatives work differently from PDE5 inhibitors and may be appropriate if tablets are contraindicated or have not helped [7]. Your GP or a specialist can discuss these options with you.

Scientific References

1. NHS. (n.d.). Erectile dysfunction (impotence). NHS website. https://www.nhs.uk/conditions/erection-problems-erectile-dysfunction/ [accessed 14 October 2026]
2. National Institute for Health and Care Excellence. (n.d.). Erectile dysfunction. Clinical Knowledge Summaries. https://cks.nice.org.uk/topics/erectile-dysfunction/ [accessed 14 October 2026]
3. Joint Formulary Committee. (n.d.). Sildenafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/sildenafil/ [accessed 14 October 2026]
4. Joint Formulary Committee. (n.d.). Tadalafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/tadalafil/ [accessed 14 October 2026]
5. Joint Formulary Committee. (n.d.). Vardenafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/vardenafil/ [accessed 14 October 2026]
6. Joint Formulary Committee. (n.d.). Avanafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/avanafil/ [accessed 14 October 2026]
7. Joint Formulary Committee. (n.d.). Alprostadil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/alprostadil/ [accessed 14 October 2026]
8. Electronic Medicines Compendium. (n.d.). Summaries of Product Characteristics and Patient Information Leaflets. https://www.medicines.org.uk/emc/ [accessed 14 October 2026]

Information on this page is for educational purposes only and is not medical advice. Prescription treatments require clinical assessment by a UK-registered prescriber. Always consult a qualified healthcare professional before starting or changing any medication.