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Enjoy sex like you used to
Metformin is the most widely prescribed medication for people with type 2 diabetes. It can improve blood sugar control and reduce the chances of developing diabetes-related complications.
Erectile dysfunction (ED) is a common health issue affecting men of all ages. It has a particularly high incidence among men with type 2 diabetes mellitus, possibly because of:
Shared risk factors like obesity
Nerve damage
Blood vessel disease
But does metformin cause erectile dysfunction?
Researchers continue to look into how metformin affects sexual health. Some research shows it may actually help reduce ED in those with diabetes, whereas other data suggests it could be a contributing factor to ED.
Read on to learn more about the relationship between metformin and ED. We’ll also discuss how metformin works in your body and what other factors can contribute to erectile dysfunction.
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Erectile dysfunction is when you’re unable to achieve an erection firm enough or maintain it long enough for sexual intercourse. It can affect men of all ages for many different reasons, such as:
Psychological factors
Neurological issues
Problems with blood flow or blood vessels
Hormonal problems
Medication side effects
ED is extremely common and may affect as many as 52 percent of men between the ages of 40 and 70.
Although it generally becomes more common with age, it can affect people at all life stages, even early adulthood. About one in four men under 40 seek medical help for ED.
Metformin is a medication used for blood sugar control in people with type 2 diabetes. It’s often the first-line treatment when lifestyle changes alone aren’t enough to lower blood glucose levels.
Over time, chronically high blood sugar can damage many tissues in your body, such as nerves and blood vessels. Damage to these tissues might contribute to other conditions like ED.
Metformin is taken orally through immediate-release or extended-release tablets. It helps lower blood sugar levels by:
Reducing liver glucose production
Decreasing intestinal absorption of glucose
Improving insulin sensitivity
Does metformin cause erectile dysfunction, though? Keep scrolling for insight.
Though anybody with a penis can develop ED, the risk is much higher in men with diabetes or metabolic syndrome.
Metabolic syndrome is a collection of five conditions that often happen together and increase a person’s risk of diabetes or heart disease. They include:
High blood sugar
Low levels of HDL (high-density lipoprotein) or “good” cholesterol
High levels of triglycerides in the blood
A large waist circumference
High blood pressure (hypertension)
The risk of erectile dysfunction is estimated to be about 3.5 times higher in men with diabetes than those without. Those with type 2 diabetes also seem to develop more severe ED or ED that doesn’t respond as well to medications.
Factors that might elevate the risk of ED in diabetic patients include:
Impaired blood flow to the penis
Blood vessel problems (endothelial dysfunction)
Nerve damage (neuropathy)
Several risk factors for ED overlap with the risk factors for type 2 diabetes, including:
Obesity
High blood pressure
Cardiovascular disease (heart disease)
High LDL (low-density lipoprotein) or “bad” cholesterol
Learn more about the connection between ED and diabetes in our blog.
The process of getting an erection is complex. It requires the coordination of many body parts, including your brain, nerves, and blood vessels.
Here’s how it works:
Sexual stimulation or sexual thoughts inhibit your sympathetic nervous system and activate parasympathetic nerves.
The activation of these nerves leads to an increased production of a molecule called nitric oxide by the lining (endothelium) of the blood vessels in your penis.
Elevated nitric oxide relaxes muscles inside your penis and its blood vessels. This causes the blood vessels in your penis to widen (a process called vasodilation) and increases blood flow. This allows blood flow to your penis to increase by 20 to 40 times.
Studies looking at the penile function of castrated men suggest that the hormone testosterone is also vital for achieving erections. However, lower-than-normal levels may still be enough to maintain erections in most men.
The increased risk of ED in people with diabetes can be attributed to multiple causes, such as:
Impaired nerve function
Impaired relaxation of the smooth muscle inside your penis
Reduced testosterone levels, which may decrease sexual desire and prevent the blood vessels in your penis from relaxing
So it’s possible ED is related to diabetes but not a result of diabetes medication.
Other conditions linked to ED include:
Heart and blood vessel diseases (cardiovascular disease)
High blood pressure
Chronic kidney disease
Multiple sclerosis
Undergoing prostate cancer treatment or getting surgery for bladder cancer could also result in erectile dysfunction.
It can also happen because of an injury to your penis, spinal cord, prostate, bladder, or pelvis.
It’s unclear if metformin causes erectile dysfunction or how it affects men sexually. Researchers are still examining whether metformin might contribute to the development of ED or protect against it.
Does metformin cause ED? Erectile dysfunction hasn’t been reported as a side effect of metformin in clinical trials. But the World Health Organization—Uppsala Monitoring Centre lists ED as a probable side effect of metformin.
As noted, low testosterone levels may play a role in ED. And low testosterone levels are common in men with type 2 diabetes, possibly due to a release of inflammatory molecules in people with insulin resistance.
In a 2021 study from China, researchers administered insulin to men with newly diagnosed type 2 diabetes. Half the participants were also given metformin. After one month, those given metformin had lower testosterone levels than the group given insulin alone. However, the erection quality didn’t vary between the two groups based on the results of the International Index of Erectile Function survey.
In a second 2021 study by the same research group, testosterone levels remained lower in the metformin group after three months.
A 2023 case study followed a 57-year-old man who developed ED shortly after taking metformin. The researchers found that discontinuing the medication relieved his ED. After restarting metformin, the patient got erectile dysfunction again, suggesting that metformin was the cause of his ED.
Some research suggests that metformin might actually help treat or prevent ED in men with diabetes. However, as of now, there’s limited human evidence looking at whether taking metformin may improve testosterone levels or ED.
Taking anti-diabetic medications such as metformin can help you keep your blood sugar levels under control while preventing damage to your blood vessels and nerves that can contribute to ED.
Theoretically, metformin might also benefit those with ED by enhancing the bioavailability of nitric oxide in the spongy part of the penis called the corpus cavernosum. This could lead to better relaxation of the muscles in your penis and improved blood flow.
Animal research and early human studies also suggest that metformin may help reduce sympathetic nervous system activity that’s often overactive in people with diabetes — a potential culprit of ED symptoms.
Beyond that, metformin can help with weight loss and weight management. As with our weight loss oral medication kits, it can be prescribed off-label for this purpose.
The most common side effects of metformin reported in clinical trials include:
Diarrhea, nausea, or vomiting
Abdominal pain or upset stomach
Constipation, bloating, or gas
Heartburn (acid reflux)
Dizziness
Headache
Upper respiratory infections
Taste disturbances
Some folks who take metformin might experience several side effects, while others might not notice any.
Besides metformin, some of the most common medications used to treat type 2 diabetes include:
Insulin. Insulin mimics a hormone produced by the pancreas. It helps lower blood sugar levels by moving glucose from your blood to other tissues.
Glucagon-like peptide (GLP)-1 receptor agonists. GLP-1 receptor agonists like Ozempic® (semaglutide) stimulate the production of insulin and help you feel full longer.
Alpha-glucosidase. These medications work by keeping your blood sugar from rising too quickly after eating.
Biguanides. Biguanides, including metformin, decrease the amount of sugar your liver makes, decrease how much your intestines absorb, and reduce insulin resistance.
Dopamine-2 agonists. Dopamine-2 agonists increase your sensitivity to insulin.
Dipeptidyl peptidase-4 (DPP-4) inhibitors. These medications block the enzyme DPP-4 (dipeptidyl peptidase 4) and help you produce more insulin when it’s needed.
Meglitinides. Meglitinides help stimulate the body’s production of insulin.
Sodium-glucose transport protein 2. These medications work by preventing the kidneys from holding on to glucose and helping the body get rid of it through urine.
Sulfonylureas. Sulfonylureas stimulate your pancreas to make your body produce more insulin. They’re among the oldest medications for type 2 diabetes but may contribute to the development of ED.
Thiazolidinediones. These medications help decrease glucose in the liver and help fat cells better use insulin.
If your healthcare provider thinks metformin or other medications may be contributing to your sexual dysfunction, they might recommend changing your prescription.
But it’s important that you don’t stop taking medications for diabetes control unless your medical provider says it’s okay.
Beyond the other diabetes drugs listed above, your provider may suggest medications such as oral phosphodiesterase type 5 (PDE5) inhibitors to help improve blood flow to your penis. This group of ED medications includes:
Sildenafil (Viagra®)
Tadalafil (Cialis®)
Vardenafil (Levitra®, Staxyn®)
Avanafil (Stendra®, Vivus®)
These medications are often first-line treatments for ED and work by enhancing relaxing blood vessels in your penis. They’re effective in many diabetic men, though some men with diabetes may require higher doses.
For those who don’t respond to oral medications, other treatment options include vacuum erection devices, penile injections, and penile implants.
Does metformin cause erectile dysfunction? It’s not listed as a side effect. Research is still ongoing on whether metformin may contribute to the development of ED or if it might actually improve erectile function.
Here’s what to keep in mind about metformin and ED:
Some evidence suggests metformin may influence testosterone levels, which could make it harder to achieve the blood flow necessary for erections and may lower your sex drive. However, in many cases, even many men with low testosterone are still able to achieve erections.
Some evidence also suggests that metformin may improve sexual function by helping preserve blood vessels and neurological health.
Whether you have diabetes or not, taking care of your overall health and reducing stress can help reduce your risk of ED and improve your quality of life.
Lifestyle changes you can make to help treat or prevent ED include:
Reducing stress
Getting regular exercise
Maintaining a healthy weight
Limiting alcohol and tobacco use
Eating a healthy diet, such as the Mediterranean diet
Treating underlying health conditions
See a urology specialist or another healthcare provider if you think that metformin or other medications may be contributing to your ED. They can talk to you about diabetes care and ED treatment options.
To explore erectile dysfunction medications and potentially access a prescription online, start with our free virtual sexual health assessment.
This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. Learn more about our editorial standards here.
Hims & Hers has strict sourcing guidelines to ensure our content is accurate and current. We rely on peer-reviewed studies, academic research institutions, and medical associations. We strive to use primary sources and refrain from using tertiary references. See a mistake? Let us know at [email protected]!
This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. Learn more about our editorial standards here.
Dr. Kelly Brown is a board certified Urologist and fellowship trained in Andrology. She is an accomplished men’s health expert with a robust background in healthcare innovation, clinical medicine, and academic research. Dr. Brown was previously Medical Director of a male fertility startup where she lead strategy and design of their digital health platform, an innovative education and telehealth model for delivering expert male fertility care.
She completed her undergraduate studies at University of North Carolina at Chapel Hill (go Heels!) with a Bachelor of Science in Radiologic Science and a Minor in Chemistry. She took a position at University of California Los Angeles as a radiologic technologist in the department of Interventional Cardiology, further solidifying her passion for medicine. She also pursued the unique opportunity to lead departmental design and operational development at the Ronald Reagan UCLA Medical Center, sparking her passion for the business of healthcare.
Dr. Brown then went on to obtain her doctorate in medicine from the prestigious Northwestern University - Feinberg School of Medicine and Masters in Business Administration from Northwestern University - Kellogg School of Management, with a concentration in Healthcare Management. During her surgical residency in Urology at University of California San Francisco, she utilized her research year to focus on innovations in telemedicine and then served as chief resident with significant contributions to clinical quality improvement. Dr. Brown then completed her Andrology Fellowship at Medical College of Wisconsin, furthering her expertise in male fertility, microsurgery, and sexual function.
Her dedication to caring for patients with compassion, understanding, as well as a unique ability to make guys instantly comfortable discussing anything from sex to sperm makes her a renowned clinician. In addition, her passion for innovation in healthcare combined with her business acumen makes her a formidable leader in the field of men’s health.
Dr. Brown is an avid adventurer; summiting Mount Kilimanjaro in Tanzania (twice!) and hiking the incredible Torres del Paine Trek in Patagonia, Chile. She deeply appreciates new challenges and diverse cultures on her travels. She lives in Denver with her husband, two children, and beloved Bernese Mountain Dog. You can find Dr. Brown on LinkedIn for more information.
Education & Training
Andrology Fellowship, Medical College of Wisconsin
Urology Residency, University of California San Francisco
M.D. Northwestern University Feinberg School of MedicineB.S. in Radiologic Science, Chemistry Minor, University of North Carolina at Chapel Hill
Published as Kelly Walker
Cowan, B, Walker, K., Rodgers, K., Agyemang, J. (2023). Hormonal Management Improves Semen Analysis Parameters in Men with Abnormal Concentration, Motility, and/or Morphology. Fertility and Sterility, Volume 118, Issue 5, e4. https://www.sciencedirect.com/journal/fertility-and-sterility/vol/120/issue/1/suppl/S
Walker, K., Gogoj, A., Honig, S., Sandlow, J. (2021). What’s New in Male Contraception? AUA Update Series, Volume 40. https://auau.auanet.org/content/update-series-2021-lesson-27-what%E2%80%99s-new-male-contraception
Walker, K., Shindel, A. (2019). AUA Erectile Dysfunction Guideline. AUA Update Series, Volume 38. https://auau.auanet.org/content/course-307
Walker, K., Ramstein, J., & Smith, J. (2019). Regret Regarding Fertility Preservation Decisions Among Male Cancer Patients. The Journal of Urology, 201(Supplement 4), e680-e681. https://www.auajournals.org/doi/10.1097/01.JU.0000556300.18991.8e
Walker, K., & Smith, J. (2019). Feasibility Study of Video Telehealth Clinic Visits in Urology. The Journal of Urology, 201(Supplement 4), e545-e545. https://www.auajournals.org/doi/10.1097/01.JU.0000556071.60611.37