In short

  • Finasteride is a common treatment option for treating male pattern hair loss.
  • It is also used for enlarged prostates (benign prostatic hyperplasia).
  • Finasteride has been proven to be highly effective, leading to the majority of users experiencing reduced hair loss and even hair regrowth.

Finasteride is a common treatment option for treating male pattern hair loss. It is also used for enlarged prostates (benign prostatic hyperplasia). Finasteride has been proven to be highly effective, leading to the majority of users experiencing reduced hair loss and even hair regrowth. 

However, as with any medication, some users may experience side effects of finasteride, which can include sexual dysfunction in men. Despite erectile dysfunction being fairly uncommon in men who take finasteride, it can be a worry for many. This article will have a closer look into how finasteride can cause erectile dysfunction and what you can do if this occurs to you.

Does Finasteride Cause Impotence?

To understand why finasteride may lead to erectile dysfunction (ED), it is useful to have an understanding of how finasteride works. 

Finasteride is a type of medication called a 5-alpha reductase inhibitor. This means that finasteride blocks the enzyme 5-alpha reductase, which usually allows the conversion of the hormone, testosterone, to another hormone called dihydrotestosterone (DHT). 

DHT reduces the blood supply to the hair follicles on the scalp, leading to their shrinkage. This causes thinner hair to grow from the follicle and eventually can result in patches of hair loss. This process is the root cause of androgenetic alopecia.

By blocking 5-alpha reductase, finasteride ensures less testosterone will be converted to DHT. This means that hair follicles in the scalp will remain a normal size and as a result, will grow thicker, healthier hair. In some cases, finasteride can recover hair follicles which have stopped producing hair, leading to the appearance of new hair growth.

However, due to affecting the way testosterone is handled within your body, finasteride may cause erectile dysfunction. It is thought that, since finasteride blocks the conversion of testosterone to DHT, there will be more unconverted testosterone. This then triggers alternative pathways in the body to convert the testosterone into another hormone called estradiol. 

Estradiol is a hormone when in increased levels in men, can lead to a reduced libido and erectile dysfunction.

In some cases, stopping finasteride can lead to long term issues, such as post-finasteride syndrome.

Should I Use Finasteride if I Have a History of ED?

The decision to take finasteride tablets is dependent on each person. Everyone is unique, and the effects a medication will have will vary from person to person. It is important to highlight that sexual side effects including erectile dysfunction is an uncommon side effect when taking finasteride, with <2% experiencing them in one particular study. 

However, if you have concerns that you may be at risk of developing ED problems, then there are ways to help prevent it or treat it.

Alternative Hair Loss Treatments

There are other medication options to treat hair loss; while dutasteride works in a similar way to finasteride, treatments such as minoxidil operate mainly on the blood vessels themselves, making it less likely you will experience side effects related to ED. However, they do have their own potential side effects, and may not be suitable for all patients.

Continue Taking Finasteride

The first option recommended would be to continue taking finasteride despite experiencing adverse effects like ED. The reason for this is because it takes a period of time for your body to get used to taking a new medication, and this then can result in some symptoms that resemble side effects. These can disappear as time goes on when you keep taking finasteride.

Reduce Finasteride to a Lower Dose

You can discuss with a healthcare professional to see if decreasing your dose of Finasteride will help with ED. However, it is important to note that reducing your finasteride might mean that it will be less effective at preventing hair loss.

Avoid Taking NSAIDs

NSAIDs are medications that include aspirin and ibuprofen. Previous studies have shown that taking NSAIDs can increase the risk of developing ED in males. So, avoiding taking NSAIDs will help reduce the chance of ED.

Erectile Dysfunction Medications

If you want to continue to take finasteride at your normal dose and are still experiencing reduced libido and erectile dysfunction, then there are treatment options available. These include other medications, such as sildenafil, that can help with ED whilst continuing finasteride. However, it is important that you talk to your doctor before making decisions on deciding if this is the best and safest treatment option for you. 

These medications may also have potential side effects, including allergic reactions and effects on your cardiovascular system. 

Conclusion

Finasteride is a highly effective and relatively safe treatment option for hair loss. A side effect that can concern many men is the chance of developing erectile dysfunction. This is fairly uncommon. 

However, if you do experience ED whilst taking finasteride, there are options out there to help. Please discuss with a healthcare professional to understand more about finasteride and ED to see if it is the best treatment option for your hair loss.

Sources

References

3 sources were selected to match the subject of this article. Link destinations were checked twice when added. This does not mean every statement has been individually source-mapped or clinically approved.

  1. Propecia 1 mg Film-Coated Tablets — Summary of Product Characteristics

    electronic medicines compendium (emc) · HTML · SmPC · Last updated on emc 14 July 2026 · Link destination checked 5 September 2026

  2. Side effects of finasteride

    NHS · HTML · medicine safety guidance · Page last reviewed 2 August 2023 · Link destination checked 5 September 2026

  3. Adverse Sexual Effects of Treatment with Finasteride or Dutasteride for Male Androgenetic Alopecia: A Systematic Review and Meta-analysis

    PubMed / Acta Dermato-Venereologica · HTML · peer-reviewed systematic review and meta-analysis · 2019; PMID 30206635 · Link destination checked 5 September 2026

Reference links open the cited source pages. If you spot something out of date, tell our content team.

Who wrote this

Written and reviewed by our team

Authored by

Safiyyah Ramzan

Content Writer

Safiyyah started working with Simple Online Pharmacy in 2023 and is currently working towards a degree in medicine. With her clinical knowledge, she aims to write clinically sound content that is easy to understand for all audiences.

Read Safiyyah’s profile

Medically reviewed by

Karim Nassar, Co-Founder, Pharmacist & Author

Karim Nassar

Co-Founder, Pharmacist & Author

Karim is a registered pharmacist with the General Pharmaceutical Council (GPhC) and was a founding member of Simple Online Healthcare in 2015. With a Master of Pharmacy degree from Strathclyde University, Karim brings a strong foundation in pharmaceutical care and a passion for leveraging digital solutions to improve patient access to healthcare.

Read Karim’s profile

Published

Last medically reviewed

Sources cited

See 3 references

Keep reading

More Finasteride advice

View all Finasteride advice