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Does Metformin Cause Erectile Dysfunction?

Metformin is usually prescribed for diabetes treatment. However, there is a controversy that metformin is linked to the development of ED. This article aims at discussing whether there is any positive or negative connection between metformin and ED with substantial scientific evidence.

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How Does A Normal Erection Work?

A normal erection is a neurovascular phenomenon that involves the flow of blood into your penis. During sex arousal, neuro signals from your brain will be sent to your penis. That’s when nitric oxide (NO), a vasodilator that stimulates blood flow, gets activated.

NO, released by the inner lining of the vascular cells, induces short-term penile smooth muscle relaxation along with quick blood flow to your penis. 

Once the blood fills the penis, its discharge will get controlled to attain and maintain a firm erection. In short, erection depends on the release of nitric oxide.

How Does Diabetes Negatively Affect Erection?

Diabetes (high blood sugar level) causes metabolic disorder leading to the dysfunction of the inner lining of the vascular cells. Hence, there will be reduction in nitric oxide synthesis and release. 

It can also damage nerves that trigger muscle relaxation essential to maintain an erection firm enough for sexual intercourse. This condition is called erectile dysfunction (ED).

Hence, diabetes is the major risk factor for erectile dysfunction. In fact, there was a threefold increased risk of ED in males with diabetes compared to non-diabetic males.

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What Is Metformin?

Metformin is the commonly prescribed first-line medication for type 2 diabetes. It regulates the sugar level released by your liver into the blood. It also enhances your body’s response to insulin, the blood sugar-regulating hormone. Hence, it is classified as an insulin sensitizer.

Does Metformin Positively Or Negatively Impact ED?

Metformin can improve ED by managing several diabetic complications that may cause ED.

A 2017 research study reported that metformin treatment can positively alter the following pathways that contribute to ED, which includes:

  • Mediating sympathetic nerve activity
  • Activating nitric oxide response to increase penile blood flow

A 2012 study showed that the metformin treatment in nondiabetic men with ED and poor response to Viagra improves erectile function.

However, there are several studies that explain how metformin negatively causes ED.

A 2016 research study concluded that metformin causes a significant reduction in sex drive, testosterone level, and induction of low testosterone-induced erectile dysfunction.

A 2021 research study, however, revealed that metformin may significantly reduce testosterone levels which may contribute to sexual dysfunction. Although, the effect of prolonged consumption of metformin on testosterone in males requires further study.

Is It Possible To Treat Metformin-induced Erectile Dysfunction While Managing Diabetes?


In case you are consuming metformin and notice increased ED or reduced sex drive, don’t hesitate to inform your doctor.

Your doctor may recommend reducing the metformin dose. If this drug has been prescribed recently, your doctor may recommend giving adequate time for your body to adjust to metformin. After several weeks, it is possible that ED might improve.

If you have severe ED, your doctor might even change the medication. In all cases, do not stop taking metformin without consulting your doctor.

Is Taking Viagra (Or Other ED Medications) With Metformin Safe?


A research study has reported that metformin taken along with Viagra (Sildenafil) can significantly improve erectile dysfunction. 

Phosphodiesterase-5 inhibitors (PDE5 inhibitors) like Viagra can relax your blood vessel walls for blood to reach the penis easily. Metformin can increase the activity of Viagra by improving insulin resistance and nitric oxide activity in the vascular endothelium of the penis. 

Still, it is always better to consult your doctor before taking metformin along with Viagra.

The Takeaway

In summary, the positive and negative findings of metformin on ED are quite contrasting and we cannot draw a definite conclusion. In fact, the connection between ED and metformin is not well studied and needs more investigation.

However, if you are experiencing erectile dysfunction, make sure to consult a doctor and inform them about Metformin consumption. 

Here at Noah, our doctors are well equipped with the knowledge to help you determine the root cause of your erectile dysfunction problem. Hearing your personal concerns, they will recommend the best treatment suited for you and can also prescribe the right medication to fix your ED problem.

Additionally, lifestyle changes such as regular exercise, quitting smoking and consuming a well-balanced diet increase the potential effect of metformin in managing ED and diabetes.


Articles featured on Noah are for informational purposes only and should not be constituted as medical advice, diagnosis or treatment. If you have any medical questions or concerns, please talk to your healthcare provider. If you're looking for a healthcare provider, click here.


Knoblovits P, et al Metformin improves erectile function in nondiabetic patients with insulin resistance and erectile dysfunction. J Clin Endocrinol Metab 2009; 94(6 suppl): Abstract P2-347 (Link)

Hu Y, Ding B, Shen Y, et al. Rapid changes in serum testosterone in men with newly diagnosed type 2 diabetes with intensive insulin and metformin. Diabetes Care. 2021;44(4):1059-1061. doi:10.2337/dc20-1558 (Link)

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, J Clin of Diagn Res. 10(12), FC21-FC26. (Link)

Rey-Valzacchi GJ, Costanzo PR, Finger LA, et al. Addition of metformin to sildenafil treatment for erectile dysfunction in eugonadal nondiabetic men with insulin resistance. A prospective, randomized, double-blind pilot study. J Androl. 2012;33(4):608-614. doi:10.2164/jandrol.111.013714 (Link)

Patel JP, Lee EH, Mena CI, Walker CN. Effects of metformin on endothelial health and erectile dysfunction. Transl Androl Urol. 2017;6(3):556-565. doi:10.21037/tau.2017.03.52 (Link)

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Published On
December 20, 2021

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