Does metformin cause ED?
Reviewed by Raagini Yedidi, MD,
Written by Lindsay Curtis
last updated: Sep 16, 2024
5 min read
Key takeaways
Metformin is a medication commonly prescribed to manage blood sugar levels in people with type 2 diabetes.
Although it can influence testosterone levels in some people, metformin is less likely to cause erectile dysfunction (ED) compared to diabetes-related factors.
Here's what we'll cover
Individuals with diabetes are three times more likely to experience erectile dysfunction (ED) than those without the condition. And given that metformin is a first-line treatment for type 2 diabetes, it’s natural to question the medication’s impact, if any, on sexual function. So, does metformin cause ED?
Ahead, we explore the link between diabetes, metformin, and ED and take a closer look at what the current research says about whether metformin can cause ED.
What is metformin?
Metformin is a first-line treatment for managing type 2 diabetes that helps control blood sugar (glucose) levels. It can reduce glucose production in the liver, decreasing the amount that’s released into the bloodstream. It can also help the body use insulin more effectively, lowering blood sugar levels by prompting cells to absorb glucose from the bloodstream and use it for energy.
In addition to its primary role in blood sugar management, some evidence suggests that metformin may contribute to weight loss in people with type 2 diabetes and obesity as well as lower the risk of cardiovascular disease in these patients.
Does metformin cause erectile dysfunction (ED)?
Erectile dysfunction (ED) is the inability to get or maintain an erection firm enough for sexual intercourse. While there are many reasons for ED, one common cause is diabetes. In fact, up to 66% of men with type 2 diabetes also experience ED.
Here’s the deal: Over time, high blood sugar levels—such as those characteristic of diabetes—can damage nerves and blood vessels throughout the body, including those in the penis. This can reduce blood flow as well as sexual sensation and responses in the penis, making it difficult for those with diabetes to achieve and maintain a firm erection.
Since metformin is one of the most commonly prescribed medications for type 2 diabetes and diabetes itself can cause ED, those who are considering the drug (or are just generally curious!) might wonder, “does metformin cause erectile dysfunction?”
Although research is ongoing, current findings on the connection between metformin and ED are somewhat complex.
Some studies suggest that metformin may help improve ED by increasing blood flow to the penis and enhancing nerve activity. Meanwhile, other findings suggest metformin may reduce testosterone levels, which can decrease libido and, in turn, contribute to ED.
Overall, the impact of metformin on testosterone and ED is relatively modest, and metformin has not been found to contribute to sexual dysfunction significantly. Rather, the impact of diabetes and subsequent damage to blood vessels and nerves are more likely to be the main drivers of ED in those with type 2 diabetes.
Side effects and risks associated with metformin
Metformin is generally safe and well-tolerated, but, like any other medication, it can cause side effects in some people, particularly at the onset of treatment. Symptoms tend to subside over time as the body adjusts to the drug, and taking metformin with food may help reduce or prevent side effects.
Common metformin side effects include:
Diarrhea
Nausea
Vomiting
Abdominal pain
Indigestion
Bloating
Loss of appetite
Less common but more serious side effects include:
Lactic acidosis. This is a rare but potentially fatal condition in which lactic acid builds up in the bloodstream, causing symptoms such as shortness of breath, dizziness, fatigue, malaise (feeling unwell), and lightheadedness. The risk of developing this side effect is higher in people with kidney disease because it can impair the body’s ability to clear metformin, which, in turn, can lead to accumulation that can cause lactic acidosis.
Vitamin B12 deficiency. Long-term use (typically 4–5 years, according to research) of metformin can interfere with the body's absorption of vitamin B12, potentially leading to a deficiency.
Hypoglycemia. Though rare, metformin can sometimes cause hypoglycemia (dangerously low blood sugar levels), especially when combined with other glucose-lowering medications or conditions. This can lead to symptoms such as confusion, weakness, excessive sweating, dizziness, shortness of breath, and heart palpitations.
What to do if you experience ED while taking metformin?
ED has many possible causes, and while metformin may reduce testosterone levels in some men (which can potentially lead to ED), other diabetes-related factors are more likely to contribute to the problem. For example, conditions common in people with diabetes, such as high blood pressure and cardiovascular (heart) disease, can cause or contribute to ED. Lifestyle habits like smoking and alcohol consumption and mental health concerns like anxiety and depression can also play a role.
If you're experiencing ED and think it might be related to your diabetes or metformin, talking to your healthcare provider is the first step to finding a solution. Your healthcare provider can determine whether metformin is truly affecting your testosterone levels or if other factors are causing the issue and adjust your treatment plan if necessary. And the good news is there are effective treatments available to help restore your sexual function and satisfaction.
Prescription medications known as phosphodiesterase type 5 (PDE5) inhibitors work in part by increasing blood flow to the penis, which can make it easier to achieve and maintain an erection for satisfactory sexual activity. Popular PDE5 inhibitors (all of which are oral drugs) include:
Vardenafil (formerly sold under the brand names Levitra and Staxyn)
Stendra (avanafil)
Viagra Important Safety Information: Read more about serious warnings and safety info.
Cialis Important Safety Information: Read more about serious warnings and safety info.
Not a fan of swallowing pills? Not to worry. Alternative formulations of PDE5 inhibitors are available, including sublingual treatment options like Ro Sparks, which combines tadalafil and sildenafil (the active ingredients in Cialis and Viagra, respectively) for fast-acting results. Another pill-free option is Ro’s Daily Rise Gummies; each fruit-flavored gummy contains 7 mg of tadalafil and offers a convenient and discreet way to manage ED.
Beyond medication, lifestyle changes can also help improve sexual function.
Exercising regularly. Consistent physical activity is one of the most effective ways to improve ED and overall sexual health. That’s because it can boost cardiovascular health as well as increase the production of nitric oxide—both of which can help improve blood flow to the penis to promote erections and alleviate ED. If you’re new to exercise or haven’t practiced in a while, incorporating regular aerobic activities like walking, running, or swimming can be a simple way to start. Research suggests aiming for at least 150 minutes of moderate aerobic exercise weekly.
Eat a healthy, balanced diet. This tactic can help improve ED by helping control blood sugar levels and supporting cardiovascular health. A Mediterranean-style diet, which focuses on incorporating whole foods like fruits, vegetables, whole grains, lean proteins, and healthy fats, has been shown to be particularly effective at addressing down-there issues (as well as promoting overall wellbeing, for that matter). What’s more, foods high in antioxidants (e.g. berries, leafy greens) as well as those rich in omega-3 fatty acids (e.g. salmon, trout) can reduce inflammation, and support heart health, all of which are important for managing erectile dysfunction.
Prioritize sufficient sleep. Getting enough shut-eye is essential for physical and mental health and can also affect sexual function. Testosterone levels naturally increase while you sleep, peaking during the first phase of deep sleep. Studies show that losing sleep, especially in the second half of the night, can significantly reduce the amount of testosterone in your body the next morning. Try to get 7 to 9 hours of quality sleep each night—something that can be more easily achieved by practicing smart sleep hygiene habits, such as creating a relaxing sleep environment, following a consistent sleep schedule, and avoiding distractions like electronics and substances like caffeine and alcohol close to bedtime.
Bottom line on metformin and ED
Metformin is a commonly prescribed medication for managing type 2 diabetes, helping control blood sugar levels. While metformin can reduce testosterone levels in some individuals and contribute to ED, diabetes-related complications are more likely to cause issues with erectile and sexual function.
DISCLAIMER
If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.
Al-Kuraishy, H. M. & Al-Gareeb, A. I. (2016). Erectile Dysfunction and Low Sex Drive in Men with Type 2 DM: The Potential Role of Diabetic Pharmacotherapy. Journal of Clinical and Diagnostic Research : JCDR, 10(12), FC21–FC26. doi: 10.7860/JCDR/2016/19971.8996. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5296448/
Allen, M. S. & Walter, E. E. (2018). Health-Related Lifestyle Factors and Sexual Dysfunction: A Meta-Analysis of Population-Based Research. The Journal of Sexual Medicine, 15(4), 458–475. doi: 10.1016/j.jsxm.2018.02.008. Retrieved from https://pubmed.ncbi.nlm.nih.gov/29523476/
Bahar, A., Elyasi, F., Moosazadeh, M., et al. (2020). Sexual dysfunction in men with type II diabetes. Caspian Journal of Internal Medicine, 11(3), 295–303. doi: 10.22088/cjim.11.3.295. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7442469/
Baranwal, N., Yu, P. K., & Siegel, N. S. (2023). Sleep physiology, pathophysiology, and sleep hygiene. Progress in Cardiovascular Diseases, 77, 59–69. doi: 10.1016/j.pcad.2023.02.005. Retrieved from https://pubmed.ncbi.nlm.nih.gov/36841492/
Bauer, S. R., Breyer, B. N., Stampfer, M. J., et al. (2020). Association of Diet With Erectile Dysfunction Among Men in the Health Professionals Follow-up Study. JAMA Network Open, 3(11), e2021701. doi: 10.1001/jamanetworkopen.2020.21701. Retrieved from https://pubmed.ncbi.nlm.nih.gov/33185675/
Cho, J. W. & Duffy, J. F. (2019). Sleep, Sleep Disorders, and Sexual Dysfunction. The World Journal of Men's Health, 37(3), 261–275. doi: 10.5534/wjmh.180045. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6704301/
de Jager, J., Kooy, A., Lehert, P., et al. (2010). Long term treatment with metformin in patients with type 2 diabetes and risk of vitamin B-12 deficiency: randomised placebo controlled trial. BMJ (Clinical Research Ed.), 340, c2181. doi: 10.1136/bmj.c2181. Retrieved from https://pubmed.ncbi.nlm.nih.gov/20488910/
Defeudis, G., Mazzilli, R., Tenuta, M., et al. (2022). Erectile dysfunction and diabetes: A melting pot of circumstances and treatments. Diabetes/Metabolism Research and Reviews, 38(2), e3494. doi: 10.1002/dmrr.3494. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9286480/
Dutta, S., Shah, R. B., Singhal, S., et al. (2023). Metformin: A Review of Potential Mechanism and Therapeutic Utility Beyond Diabetes. Drug Design, Development and Therapy, 17, 1907–1932. doi: 10.2147/DDDT.S409373. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10312383/
Dyatlova, N., Tobarran, N. V., Kannan, L., et al. (2023). Metformin-Associated Lactic Acidosis (MALA). StatPearls. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK580485/
Gerbild, H., Larsen, C. M., Graugaard, C., et al. (2018). Physical Activity to Improve Erectile Function: A Systematic Review of Intervention Studies. Sexual Medicine, 6(2), 75–89. doi: 10.1016/j.esxm.2018.02.001. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5960035/
Gonzalez-Lopez, C. & Wojeck, B. S. (2023). Role of metformin in the management of type 2 diabetes: recent advances. Polish Archives of Internal Medicine, 133(6), 16511. doi: 10.20452/pamw.16511. Retrieved from https://pubmed.ncbi.nlm.nih.gov/37317976/
He, Z., Yin, G., Li, Q. Q., et al. (2021). Diabetes Mellitus Causes Male Reproductive Dysfunction: A Review of the Evidence and Mechanisms. In Vivo (Athens, Greece), 35(5), 2503–2511. doi: 10.21873/invivo.12531. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8408700/
Imprialos, K. P., Stavropoulos, K., Doumas, M., et al. (2018). Sexual Dysfunction, Cardiovascular Risk and Effects of Pharmacotherapy. Current Vascular Pharmacology, 16(2), 130–142. doi: 10.2174/1570161115666170609101502. Retrieved from https://pubmed.ncbi.nlm.nih.gov/28595561/
Joseph, C. M. C. (2021). Symptomatic Hypoglycemia During Treatment with a Therapeutic Dose of Metformin. The American Journal of Case Reports, 22, e931311. doi: 10.12659/AJCR.931311. Retrieved from https://pubmed.ncbi.nlm.nih.gov/34075013/
Khattab, R., Albannawi, M., Alhajjmohammed, D., et al. (2023). Metformin-Induced Vitamin B12 Deficiency among Type 2 Diabetes Mellitus' Patients: A Systematic Review. Current Diabetes Reviews, 19(4), e180422203716. doi: 10.2174/1573399818666220418080959. Retrieved from https://pubmed.ncbi.nlm.nih.gov/35440313/
Kouidrat, Y., Pizzol, D., Cosco, T., et al. (2017). High prevalence of erectile dysfunction in diabetes: a systematic review and meta-analysis of 145 studies. Diabetic Medicine: A Journal of the British Diabetic Association, 34(9), 1185–1192. doi: 10.1111/dme.13403. Retrieved from https://pubmed.ncbi.nlm.nih.gov/28722225/
Nakrani, M. N., Wineland, R. H., & Anjum, F. (2023). Physiology, Glucose Metabolism. StatPearls. Retrieved from https://pubmed.ncbi.nlm.nih.gov/32809434/
Ngu, M. H., Zakaria, R., Mohd Zulkifli, M., et al. (2023). Erectile dysfunction as a possible important side effect of metformin: A case report. Malaysian Family Physician: The Official Journal of the Academy of Family Physicians of Malaysia, 18, 20. doi: 10.51866/cr.282. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10191187/
Odetayo, A. F. & Olayaki, L. A. (2023). Omega 3 fatty acid improves sexual and erectile function in BPF-treated rats by upregulating NO/cGMP signaling and steroidogenic enzymes activities. Scientific Reports, 13(1), 18060. doi: 10.1038/s41598-023-45344-4. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10593954/
Parmar, R. S., Verma, S., Neelkamal, Pathak, V. K., et al. (2022). Prevalence of erectile dysfunction in Type 2 diabetes mellitus (T2DM) and its predictors among diabetic men. Journal of Family Medicine and Primary Care, 11(7), 3875–3879. doi: 10.4103/jfmpc.jfmpc_1130_21. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9648286/
Patel, J. P., Lee, E. H., Mena, C. I., et al. (2017). Effects of metformin on endothelial health and erectile dysfunction. Translational Andrology and Urology, 6(3), 556–565. doi: 10.21037/tau.2017.03.52. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5503973/
Rahaman, M. M., Hossain, R., Herrera-Bravo, J., et al. (2023). Natural antioxidants from some fruits, seeds, foods, natural products, and associated health benefits: An update. Food Science & Nutrition, 11(4), 1657–1670. doi: 10.1002/fsn3.3217. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10084981/
Ram, E., Lavee, J., Tenenbaum, A., et al. (2019). Metformin therapy in patients with diabetes mellitus is associated with a reduced risk of vasculopathy and cardiovascular mortality after heart transplantation. Cardiovascular Diabetology, 18(1), 118. doi: 10.1186/s12933-019-0925-y. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7243386/
Rena, G., Hardie, D. G., & Pearson, E. R. (2017). The mechanisms of action of metformin. Diabetologia, 60(9), 1577–1585. doi: 10.1007/s00125-017-4342-z. Retrieved from https://pubmed.ncbi.nlm.nih.gov/28776086/
Rizk, P. J., Kohn, T. P., Pastuszak, A. W., & Khera, M. (2017). Testosterone therapy improves erectile function and libido in hypogonadal men. Current Opinion in Urology, 27(6), 511–515. doi: 10.1097/MOU.0000000000000442. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5649360/
Sakouhi, M., Matmour, D., Belakhdar, K., & Kraroubi, A. (2023). Étude Transversale sur les Effets Indésirables de la Chlorhydrate de Métformine chez 130 Patients Diabétiques Type 2 Admis au Centre Médical et à la Maison du Diabète de Sidi Bel-Abbès [Cross-Sectional Study on Adverse Effects of Metformin Hydrochloride on 130 Patients Type 2 Diabetic Admitted to Medical Center and Diabetes Home of Sidi Bel-Abbès]. Annales Pharmaceutiques Francaises, 81(4), 684–695. doi: 10.1016/j.pharma.2022.11.013. Retrieved from https://pubmed.ncbi.nlm.nih.gov/36464072/
Silva, A. B., Sousa, N., Azevedo, L. F., & Martins, C. (2017). Physical activity and exercise for erectile dysfunction: systematic review and meta-analysis. British Journal of Sports Medicine, 51(19), 1419–1424. doi: 10.1136/bjsports-2016-096418. Retrieved from https://pubmed.ncbi.nlm.nih.gov/27707739/=
Soukas, A. A., Hao, H., & Wu, L. (2019). Metformin as Anti-Aging Therapy: Is It for Everyone?. Trends in Endocrinology and Metabolism: TEM, 30(10), 745–755. doi: 10.1016/j.tem.2019.07.015. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6779524/
Tseng, C. H. (2022). The Effect of Metformin on Male Reproductive Function and Prostate: An Updated Review. The World Journal of Men's Health, 40(1), 11–29. doi: 10.5534/wjmh.210001. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8761231/
Xiao, Y., Xie, T., Peng, J., et al. (2023). Factors associated with anxiety and depression in patients with erectile dysfunction: a cross-sectional study. BMC Psychology, 11(1), 36. doi: 10.1186/s40359-023-01074-w. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9899110/
Yannas, D., Frizza, F., Vignozzi, L., et al. (2021). Erectile Dysfunction Is a Hallmark of Cardiovascular Disease: Unavoidable Matter of Fact or Opportunity to Improve Men's Health?. Journal of Clinical Medicine, 10(10), 2221. doi: 10.3390/jcm10102221. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8161068/
How we reviewed this article
Current version
Lindsay Curtis
Raagini Yedidi, MD
About the medical reviewer
