Metformin and Erectile Dysfunction: Link Between and Sexual Side Effects

Does metformin cause erectile dysfunction? That’s one of the most common questions men ask when they start this widely prescribed diabetes medication. The honest answer is: it’s complicated.

Metformin itself usually doesn’t directly cause ED, but in some cases, it may influence testosterone, sexual desire, or erections. At the same time, it can also improve sexual health by lowering blood sugar, supporting weight loss, and protecting blood vessels.

In this article, we’ll break down what the science says about metformin and erectile dysfunction, the risks, the possible benefits, and why diabetes itself often plays a bigger role than the medication.

What is Metformin, and Why Is It Prescribed

It is a well-known, FDA-approved medication used to help manage type 2 diabetes. It works by lowering how much sugar your body absorbs from food, reducing the sugar your liver makes, and helping your body respond better to insulin, i.e, lowers the blood sugar levels in the body.

Doctors usually recommend it in conjunction with a healthy diet and regular exercise for optimal results. Interestingly, its benefits aren’t limited[1] to people with diabetes. Doctors sometimes prescribe it for other conditions too, like Prediabetes, Gestational diabetes, and Polycystic ovarian syndrome (PCOS)

Does Metformin Cause Erectile Dysfunction?

The relationship between metformin and erectile dysfunction is complex. There are both potential negative and positive effects of metformin on erections. Some studies link it to erectile dysfunction[3], possibly due to its testosterone level-lowering effect and changes in how muscles in the penis contract.

A well-documented case[4] study in 2023 involved a 57-year-old man who developed erectile dysfunction shortly after starting metformin. His symptoms improved after stopping the metformin and came back when he restarted it.

The World Health Organization’s Uppsala Monitoring Centre[5] has flagged erectile dysfunction as a probable side effect of metformin. Even though erectile dysfunction as a side effect of metformin is rare, it can occur.

According to Allo Health, nearly 1 in 2 men experience erectile dysfunction, which is based on our internal clinical data of more than 2.5 lakh patients who have visited our clinics.

Let's dive deeper.

Metformin and Erectile Dysfunction: The Link

One of the more consistent findings across studies[2] is that it may reduce testosterone levels in men. Research has shown that within just 1 to 3 months of starting metformin, some men experience a noticeable drop in testosterone levels.

Men taking metformin have been found to have lower total, free, and bioavailable testosterone compared to those on other diabetes medications like sulfonylureas.

Why does this matter? Testosterone plays a key role in sex drive, energy, mood, and erectile function. Lower testosterone also affects blood flow in the penis(penile blood flow), contributing to erectile dysfunction

This decline in testosterone level could, in some cases, overrule the positive effects of better blood sugar control.

How Does Metformin Reduce Testosterone Levels

It may affect male sexual function through several pathways:

• It can inhibit enzymes involved in testosterone production, which can reduce testosterone levels.
• It may also affect Sertoli and Leydig cells[6] -the cells responsible for supporting sperm production and making testosterone.

Can Metformin Improve Erectile Dysfunction in Some Cases?

For many men, especially those with type 2 diabetes, it can indirectly improve sexual function by supporting overall health. Here's how:

Blood Sugar Control

• High blood sugar levels[8] in diabetes can leave you feeling drained, foggy, and fatigued - all of which can dampen your sex drive.
• Metformin improves insulin sensitivity and helps stabilize blood glucose levels, which may boost your overall energy, stamina, and interest in sex.

Weight Loss

• Obesity is a common concern among men with type 2 diabetes, and obesity a known risk factor for erectile dysfunction.
• Metformin can sometimes support weight loss, which helps boost blood circulation and heart health, two key factors for better sexual performance.

Reduced Inflammation

• Chronic inflammation is common in diabetes and obesity, and it harms your blood vessels, including those that supply the penis.
• Metformin has anti-inflammatory effects, which may help improve endothelial function[9](the inner lining of the blood vessels).
• This leads to increased nitric oxide production(which helps in relaxing blood vessels) and thus supports healthier erections.

Improved Hormonal Balance

• While metformin can lower testosterone, it also addresses insulin resistance-related hormonal imbalances.
• For men whose sexual dysfunction comes from an insulin-driven hormone imbalance, metformin may provide benefits.

How Diabetes Itself Affects Erections

Let's try to understand the link between diabetes and erectile dysfunction and how diabetes can directly and indirectly affect sexual health in men[7]:

1. Blood Vessel Damage

High blood sugar → Damages blood vessel walls → Less nitric oxide (NO) → Poor blood flow → ED

2. Atherosclerosis (Plaque Buildup)

Diabetes → Narrowed arteries → Reduced penile blood flow → Weaker erection

3. Nerve Damage (Neuropathy)

High blood sugar → Damages erection-control nerves → Muscles don’t relax → Impaired erectile response

The relationship between metformin and male sexual health is a complex one that depends on various factors, including individual health conditions and the specific effects of the drug.

It is sometimes difficult to understand and differentiate whether the impact on sexual health is due to the medication or to diabetes itself.

Diabetes, not metformin, is often the bigger reason men experience erectile issues. By managing blood sugar, we’re also protecting the very blood vessels and nerves needed for healthy erections.

When to Talk to Your Doctor

Experiencing changes in sexual function along with diabetes can feel distressing, but you don’t have to handle it alone. Open communication with your doctor is the best way to manage these side effects effectively. Consider reaching out to your doctor if you notice:

Changes in Libido

• A sudden drop or shift in sex drive.
• If it’s affecting your quality of life or relationships.

Erectile Dysfunction Symptoms

• Difficulty getting or maintaining an erection after starting metformin.
• Your doctor can help determine whether metformin is part of the issue and suggest alternatives or supportive treatments.

Other Side Effects

• Persistent fatigue, digestive issues, or mood changes.
• If these symptoms dampen sexual interest or performance, it’s worth asking about adjusting your treatment.

4 Tips to Manage Sexual Health While on Metformin

1. Monitor Your Symptoms

• Keep a simple log of changes in your sex drive, mood, energy, stress, or erectile function.
• Note when you started metformin and any patterns you notice. This can help your doctor figure out what’s really happening.

2. Avoid Self-Medication

• Many supplements claim to boost libido, but not all are safe to take with metformin.
• Always talk to your doctor before trying anything new. Some options may help, but only if they don’t interfere with your treatment.

3. Lifestyle Changes

• Exercise regularly, eat a balanced whole-food diet, limit alcohol, and quit smoking.
• These habits improve blood sugar levels, circulation, energy, and hormone balance, all essential for healthy sexual function.

4. Address Emotional and Mental Health

• Stress, anxiety, or low mood can directly affect your sex life.
• Remember, your mind and body are connected -caring for both is key to overall sexual well-being.

Key Takeaway

Does metformin cause erectile dysfunction? It is rare, but it can cause erectile dysfunction by affecting testosterone levels.

But now what we do know is that the effects of metformin vary from person to person. That’s why it’s important to listen to your body and stay mindful of any changes you experience while on the medication.

If you notice anything unusual, like shifts in your sex drive, energy, or mood, don’t ignore it. Most importantly, never stop taking metformin without talking to your doctor first.