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Do Blood Thinners Affect Erections?
Do Blood Thinners Affect Erections?
Dr. Zoë Lees (PhD)
Dr. Sophie Dix (BSc, PhD)
12 November 2024 | Updated: 4 August 2026
4 August 2026
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:
- NHS. Overview - Anticoagulant Medicines [Internet]. NHS. 2021. Available from: https://www.nhs.uk/conditions/anticoagulants/
- 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
- 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/
- How the Penis Works [Internet]. WebMD. Available from: https://www.webmd.com/erectile-dysfunction/how-an-erection-occurs
- 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.
- NHS. Erectile dysfunction (impotence) [Internet]. NHS. 2019. Available from: https://www.nhs.uk/conditions/erection-problems-erectile-dysfunction/
- 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/
- Drugs that may cause erection problems: MedlinePlus Medical Encyclopedia [Internet]. Medlineplus.gov. 2019. Available from: https://medlineplus.gov/ency/article/004024.htm
- Dhaliwal A, Gupta M. PDE5 Inhibitor [Internet]. PubMed. Treasure Island (FL): StatPearls Publishing; 2020. Available from: https://www.ncbi.nlm.nih.gov/books/NBK549843/
Next scheduled review date: 4 August 2029
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Authors
Written by: Dr. Zoë Lees (PhD)
Dr. Zoë Lees is a medical writer at MedExpress specialising in obesity and health communication. She completed her PhD at the University of Glasgow, where she investigated adipose tissue (fat tissue) function in pregnancies complicated by pre-eclampsia and gestational diabetes. Her work focuses on translating complex clinical evidence into clear, engaging and evidence-based health information for patients and the public. At MedExpress, Zoë contributes to clinical content, educational resources and media communications across areas including weight management, GLP-1 therapies and metabolic disease. Zoë is particularly interested in improving public understanding of obesity as a chronic condition and ensuring patients have access to accurate, accessible health information grounded in current scientific evidence.
Medically reviewed by: Dr. Sophie Dix (BSc, PhD)
Dr. Sophie Dix is Head of Medical Affairs at MedExpress. A behavioural neuroscientist by training, Sophie has spent 30 years working at the intersection of medical research, pharmacology, technology and patient communication across the pharmaceutical industry, health technology and charity sectors. At MedExpress, Sophie's role is to ensure that everything the organisation does is grounded in the most current science. That means translating complex clinical evidence into accessible health information across the website, clinical pathways and media communications. It also means working with external press and broadcast media as a named expert commentator, making the science behind weight management and GLP-1 treatments understandable to a general audience. A core part of Sophie's work is building MedExpress's Real-World Evidence (RWE) programme: learning systematically from patient outcomes to understand what works in practice, not just in clinical trials. This patient-level insight feeds directly into improving patient experience and health outcomes. Sophie believes that patients make better decisions when they have access to accurate, evidence-based information. As an advocate for meaningful change in how obesity is understood, Sophie works to reduce stigma and raise awareness of the condition as an illness. This includes reframing the conversation around GLP-1s from aesthetics to public health, while highlighting the health benefits of weight loss and weight management.
Note from the experts
Remember: This blog shouldn’t be regarded as medical advice, diagnosis, or treatment. We make sure everything we publish is fact checked by clinical experts and regularly reviewed, but it may not always reflect the most recent health guidelines. Always speak to your doctor about any health concerns you have.