Does Metformin Cause Erectile Dysfunction? Here’s What the Research Says
Key takeaways:
The link between metformin and erectile dysfunction (ED) isn’t fully clear. Some studies suggest that metformin may lower testosterone levels and libido (sex drive), potentially contributing to ED. Others suggest that it can improve blood flow and erections.
Diabetes itself is a common risk factor for ED. High blood glucose (blood sugar) can damage the blood vessels and nerves involved in erections. Diabetes is also linked to other health conditions that can worsen ED, such as high blood pressure and high cholesterol.
Managing ED often requires a combination of short- and long-term strategies. Medications such as Viagra (sildenafil) can help in the short term, while lifestyle changes, mental health support, and regular checkups can make a difference over time.
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You’ve been doing your part to manage Type 2 diabetes. You’ve made changes to your diet and started moving more, and your healthcare professional prescribed metformin to help manage your blood glucose (blood sugar). But now you’re noticing something you didn’t expect — trouble with erections. You can’t help but wonder if your medication could be partly to blame.
If this sounds familiar, you're not alone. Many men who take metformin have similar questions about how it might affect their erections and broader sexual health.
Here, we’ll break down what the research says about the link between metformin and erectile dysfunction (ED).
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Does metformin cause erectile dysfunction?
Maybe. There’s not a clear answer. Some studies indicate yes, while others push back against this notion. Diabetes itself also increases the risk of ED, which makes it hard to pinpoint metformin's specific role. Here’s a summary of what we know.
These small studies have linked metformin to ED:
One analysis found a connection between metformin use and ED among men with Type 2 diabetes.
A few studies suggest that metformin may be linked to lower testosterone levels and sex drive (libido). Lower testosterone levels had mixed effects on erection quality.
In a case report, one man developed ED a couple of weeks after starting metformin. His symptoms went away after he stopped taking metformin, and they came back 15 days after he restarted it. (Keep in mind that case reports are helpful for highlighting unusual cases. They’re not able to establish cause-and-effect relationships.)
Other data suggests that metformin has neutral or beneficial effects on ED:
Some researchers believe that metformin can improve penile blood flow. This may be useful for treating ED cases related to reduced blood flow (called arteriogenic ED).
One small, randomized study looked at men without diabetes who weren't responding well to Viagra (sildenafil) for ED. Researchers found that adding metformin to their treatment plan improved their erectile function after 4 months of treatment.
All said, the jury is still out. Larger studies are needed to clarify these findings and determine if metformin impacts erections and, if so, how. If you experience ED while taking metformin, reach out to your healthcare professional for advice.
The link between diabetes and erectile dysfunction
Diabetes is a common cause of ED. Generally speaking, it’s related to how high blood sugar affects your body over time. Consistently elevated blood sugar levels can damage the blood vessels and nerves that contribute to sexual function. This damage can reduce blood flow to the penis and interfere with the signals that trigger and maintain an erection.
Diabetes can also affect hormone levels, particularly testosterone levels. Many men with Type 2 diabetes have lower-than-normal testosterone, which can reduce libido and worsen ED symptoms. What’s more, diabetes is often linked to other health issues — such as high blood pressure, high cholesterol, and obesity — that can contribute to ED. Medications for diabetes and related conditions may contribute to these symptoms, as well.
This GoodRx Health article about diabetes and ED discusses the link between the two in-depth.
Diabetes and men’s health: Diabetes is a known risk factor for erectile dysfunction (ED). GoodRx physicians detail why it happens and how to manage it.
New to metformin? It’s normal to have questions. Here, pharmacists answer some of the most common questions about metformin, including how long it takes to work.
Metformin side effects: Metformin’s most well-known side effect is diarrhea, but other risks are also possible.
How to treat erectile dysfunction from metformin or diabetes
Managing ED from metformin or diabetes often calls for a blended approach. Some options can help right away, while others work better over time.
Short-term ED management tips
If you’re experiencing ED, several treatments can help. Oral pills, such Viagra or Cialis (tadalafil), are generally the most convenient options. If these don’t work for you, your prescriber might recommend penile injections. They may also recommend mechanical options, such as vacuum pumps or tension rings.
If you think that metformin is fully or partially responsible for your symptoms, talk to your prescriber. Depending on your situation, you may be able to switch to a different medication that your body tolerates better. Don’t stop taking metformin on your own, though.
Long-term ED management tips
One of the most foundational things you can do to improve ED over time is keeping your blood sugar in its target range. Doing so helps protect the blood vessels and nerves that support sexual function. Maintaining this target range may include various lifestyle changes, such as following a diabetes-friendly diet, incorporating more activity into your daily routine, and working toward your target body weight. Minimizing your alcohol intake helps, too.
Other strategies include:
Taking care of your mental health: Living with diabetes can be stressful, and depression or anxiety can make ED worse. Several treatments are available, though. Taking the initiative to improve your mental health can indirectly improve your sexual function.
Investing in your relationship: ED can strain relationships, leading to added stress and anxiety. Maintaining open communication with your partner and, if necessary, seeking couples therapy can help you maintain intimacy and reduce performance anxiety.
Staying on top of regular checkups: ED may be a sign of broader health issues. Regular check-ins for heart health, kidney function, and other diabetes complications can help catch problems early — before they affect your sexual health even more.
Quiz: Is it erectile dysfunction?
Frequently asked questions
No. Metformin isn’t known to lower sex drive in women. Some data suggests it may actually improve sexual function. Research on women living with conditions such as Type 2 diabetes or polycystic ovary syndrome has found that the medication can enhance certain aspects of sexual function, such as sex drive, satisfaction, and lubrication.
Yes. Most people can take Viagra with metformin. The pair don’t interact with each other. If you’re interested in taking an ED medication such as Viagra, ask a healthcare professional if it’s safe for you to try.
No. Metformin doesn’t appear to harm the prostate. In some cases, it may even be beneficial. For instance, some research suggests that metformin may lower the risk of developing prostate cancer or slow its progression. But more studies are needed to confirm this. Some data shows that it doesn’t make a significant difference.
The bottom line
Metformin is an oral medication that treats Type 2 diabetes. Metformin doesn’t appear to directly cause erectile dysfunction (ED), but some research suggests that it might lower testosterone and libido (sex drive) in men — which could affect their erections. Other studies suggest that metformin might actually improve blood flow and help with ED. Diabetes itself is a common risk factor for ED, though, making it tough to tease apart what’s driving your symptoms.
If you’re experiencing ED while taking metformin, talk to your healthcare professional. They can help you figure out what’s contributing to your symptoms and how to address them.
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References
Al-Kuraishy, H. M., et al. (2016). Erectile dysfunction and low sex drive in men with type 2 DM: The potential role of diabetic pharmacotherapy. Journal of Clinical & Diagnostic Research.
American Diabetes Association. (n.d.). Low testosterone.
Cai, T., et al. (2021). Effect of metformin on testosterone levels in male patients with Type 2 diabetes mellitus treated with insulin. Frontiers in Endocrinology.
Centers for Disease Control and Prevention. (2024). Diabetes and men.
Feng, L., et al. (2024). Causal association between antidiabetic drugs and erectile dysfunction: Evidence from Mendelian randomization. Frontiers in Endocrinology.
Gateva, A., et al. (2012). Sexual function in patients with PCOS and/or obesity before and after metformin treatment. Advances in Sexual Medicine.
He, K., et al. (2019). The effect of metformin therapy on incidence and prognosis in prostate cancer: A systematic review and meta-analysis. Scientific Reports.
Hu, Y., et al. (2021). Rapid changes in serum testosterone in men with newly diagnosed Type 2 diabetes with intensive insulin and metformin. Diabetes Care.
Kitaw, T. A., et al. (2024). The global burden of erectile dysfunction and its associated risk factors in diabetic patients: An umbrella reviews. BMC Public Health.
Krysiak, R., et al. (2017). Sexual functioning and depressive symptoms in women with diabetes and prediabetes receiving metformin therapy: A pilot study. Experimental and Clinical Endocrinology & Diabetes.
Kuhl, E. A. (2024). Metformin does not slow disease progression in low-risk prostate cancer. ASCO Daily News.
Ngu, M. H., et al. (2023). Erectile dysfunction as a possible important side effect of metformin: A case report. Malaysian Family Physician.
Patel, J. P., et al. (2017). Effects of metformin on endothelial health and erectile dysfunction. Translational Andrology and Urology.
Rey-Valzacchi, G. J., et al. (2013). Addition of metformin to sildenafil treatment for erectile dysfunction in eugonadal nondiabetic men with insulin resistance. A prospective, randomized, double-blind pilot study. Journal of Andrology.
Tseng, C.-H. (2021). The effect of metformin on male reproductive function and prostate: An updated review. The World Journal of Men’s Health.
Yang, B., et al. (2025). Effects of anti-diabetic drugs on erectile dysfunction: A systematic review and meta-analysis. Diabetes, Metabolic Syndrome and Obesity.
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