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Dr Ashwin Sharma

Article by Dr Ashwin Sharma

Do Blood Thinners Affect Erections?


If you’re at risk of blood clots due to a cardiovascular condition or surgery, your doctor may prescribe you a blood thinning medication. [1] Because these drugs affect your blood, and healthy blood flow is essential for strong erections, you may be worried that taking them could have an effect on your sexual function. In this post, we break down how blood thinners work, the role of blood vessels in erectile function and whether anti-clotting medications can influence your sexual performance. 

What are blood thinners?

Blood thinners are a type of prescription drug that prevents the formation of blood clots in your blood vessels. There are two common types of blood thinners: anticoagulant medication (heparin and warfarin) and antiplatelet medication (aspirin). 

They’re commonly used to treat serious health conditions like deep vein thrombosis (a blood clot in a vein, usually in your leg), pulmonary embolism (a blood clot in your lung) or stroke.

How blood thinners work

Blood clots are a normal part of your body’s healing process. They form in a process called coagulation, where blood cells and proteins bind together to stop bleeding if you get an injury. [2] These clots usually dissolve on their own, but sometimes you may develop abnormal blood clots that break free and travel to your lungs or brain. This could cause a pulmonary embolism or stroke, which can be life-threatening.

There are many reasons why you may be at risk of blood clots, including:

  • Major surgery (particularly involving the abdomen, pelvis, hip, or legs)
  • Family history of blood clots 
  • Smoking 
  • Pregnancy
  • Oestrogen-containing contraceptives or hormone replacement therapy 
  • Long periods of sitting, such as car or plane trips
  • Prolonged bed rest due to hospitalisation or illness
  • Cancer
  • Overweight or Obesity 

These factors can slow or block normal blood flow, which may cause clots to form. Blood thinners help by preventing the blood from clotting too easily, either by stopping blood cells called platelets from clumping or by blocking certain proteins involved in the clotting process. This lowers the risk of dangerous clots forming.

The role of blood flow in erections 

Healthy blood flow is essential for strong erections. When you experience sexual arousal, your brain sends chemical signals to the smooth muscles around the arteries in your penis. This causes them to relax, widening the blood vessels and increasing blood flow into your penis. Once more blood enters your penis, pressure traps it, causing a sustained erection. [4]

Erections are usually the result of sexual stimulation, although sometimes they can occur spontaneously. 

What is erectile dysfunction?

Erectile dysfunction (ED) is the inability to get or maintain an erection hard enough for sexual activity. It’s a very common condition, affecting 4.3 million men of all ages across the UK. [5] 

ED can have many causes, including: high blood pressure, diabetes, mental health conditions, hormonal imbalances or some medicines. [6]

Can blood thinners cause erectile dysfunction?

Because blood thinners affect your blood flow and blood vessels, you may be wondering if they can affect your erectile function. There’s currently no evidence to suggest that blood thinners cause erectile dysfunction, or worsen existing ED symptoms. One study actually found that aspirin, an antiplatelet medication, may actually boost sexual function in men whose ED is caused by heart disease. [7]

Often, you take blood thinners with other prescription medications for cardiovascular disease. If you notice ED symptoms after starting treatment, it could be another drug that’s causing it. Some heart failure and blood pressure medications can cause sexual dysfunction. [8] Plus, some conditions themselves also put you at increased risk of erectile dysfunction. 

If you think treatments for other medical conditions are impacting your sexual health, speak to your doctor or clinical team. There are ways to help improve your sexual performance, without stopping treatments and compromising your heart health.

Treating erectile dysfunction 

ED can be treated using a class of drug known as PDE5 inhibitors. These medications help your blood vessels relax when you experience sexual arousal, improving blood flow to your penis and making it easier for you to get an erection. [9]

There are a variety of treatment options available to you, from popular brand-name medications like Viagra and Cialis to generic versions, like sildenafil and tadalafil. Most erectile dysfunction treatments must be prescribed by a healthcare professional working for a licensed healthcare provider like MedExpress. Our clinicians assess your medical history to find the most suitable treatment plan for you. Some ED medications can interact with other drugs and cause adverse effects, so it’s important you let your prescriber know about any other medications you take during your consultation. 

Looking to take control of your sexual performance? Explore your treatment options today

References: 

1. NHS. Overview – Anticoagulant Medicines [Internet]. NHS. 2021. Available from: https://www.nhs.uk/conditions/anticoagulants/ 

2. NHLBI. Blood Clotting Disorders – How Does Blood Clot? | NHLBI, NIH [Internet]. www.nhlbi.nih.gov. 2022. Available from: https://www.nhlbi.nih.gov/health/clotting-disorders/how-blood-clots 

3. Fogelson AL, Neeves KB. Fluid Mechanics of Blood Clot Formation. Annual review of fluid mechanics [Internet]. 2015 Jan 1 [cited 2020 May 20];47:377–403. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4519838/ 

4. How the Penis Works [Internet]. WebMD. Available from: https://www.webmd.com/erectile-dysfunction/how-an-erection-occurs 

5. Kessler A, Sollie S, Challacombe B, Briggs K, Van Hemelrijck M. The global prevalence of erectile dysfunction: a review. BJU International. 2019 Jul 2;124(4):587–99. 

6. NHS . Erectile dysfunction (impotence) [Internet]. NHS. 2019. Available from: https://www.nhs.uk/conditions/erection-problems-erectile-dysfunction/ 

7. Irfan M, Ismail SB, Noor NM, Hussain NHN. Efficacy of Aspirin for Vasculogenic Erectile Dysfunction in Men: A Meta-Analysis of Randomized Control Trials. American Journal of Men’s Health [Internet]. 2020 Sep 1 [cited 2021 Feb 6];14(5):1557988320969082. Available from: https://pubmed.ncbi.nlm.nih.gov/33111628/ 

8. Drugs that may cause erection problems: MedlinePlus Medical Encyclopedia [Internet]. Medlineplus.gov. 2019. Available from: https://medlineplus.gov/ency/article/004024.htm 

9. Dhaliwal A, Gupta M. PDE5 Inhibitor [Internet]. PubMed. Treasure Island (FL): StatPearls Publishing; 2020. Available from: https://www.ncbi.nlm.nih.gov/books/NBK549843/

Dr Ashwin Sharma
Dr Ashwin Sharma
Dr Ashwin Sharma is a medical doctor and writer with a particular interest in health technology, artificial intelligence and medical weight loss. He completed his training at the University of Leicester and Imperial College London, and has since been exploring the intersections of medicine, technology, and communication.
Originally published November 12 2024, updated November 12 2024