Based on NIH | Does metformin increase the risk of sexual side effects, such as decreased libido or erectile dysfunction?

Metformin does not appear to commonly cause sexual side effects like decreased libido or erectile dysfunction; in people with diabetes, better glucose control with metformin may even help protect sexual function by reducing diabetes-related nerve and blood vessel damage. ^{[1] [2]} In official consumer drug information, “decreased sexual ability in men and women” is described as a complication of diabetes rather than a typical direct side effect of metformin. ^{[3] [4]}

Quick summary

• Evidence suggests antihyperglycemic drugs, including metformin, tend to be neutral or protective for erectile function when they improve diabetes control. ^[5]
• Large, authoritative drug labels for metformin do not list decreased libido or erectile dysfunction as typical adverse effects. ^{[6] [7]}
• Diabetes itself is strongly linked to sexual dysfunction; metformin’s role in improving metabolic status may lower that overall risk, though individual responses can vary. ^{[1] [2]}

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What official information says

• Metformin’s consumer and professional drug summaries emphasize gastrointestinal effects, B12 deficiency risk over time, and rare serious events (like lactic acidosis), but do not list erectile dysfunction or reduced libido as common metformin adverse effects. ^{[6] [7]}
• Consumer-facing summaries that mention “decreased sexual ability” do so in the context of complications from diabetes (neuropathy), not as a direct metformin effect. ^{[3] [4]}

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What research shows about diabetes and sexual function

• Diabetes is a major risk factor for erectile dysfunction (ED) in men, roughly tripling risk compared with men without diabetes, largely due to high blood sugar damaging blood vessels and nerves. Improving glucose control and cardiometabolic health helps. ^{[1] [2]}
• A systematic review found that antihyperglycemic therapies overall show a protective role for erectile function, with dietary patterns like the Mediterranean diet also beneficial. ^[5]

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Metformin and hormones or libido

• In men with obesity and low testosterone (without diabetes), a randomized trial showed metformin improved insulin resistance but did not produce significant changes in erectile function on its own; combination with testosterone increased testosterone levels but still did not change erectile function measures over one year. ^[8]
• These findings suggest metformin doesn’t typically worsen sexual function, and hormonal changes are not a consistent effect without other interventions. ^[8]

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Practical points for users

• If you notice decreased libido or erectile difficulties while taking metformin, there are several possible contributors:
  • Underlying diabetes severity or fluctuating blood sugar can impair sexual function. Optimizing glucose control remains central. ^{[1] [2]}
  • Other medications (for blood pressure or depression, for example) are known causes of ED; reviewing your full medication list can help identify culprits. ^{[9] [10]}
  • Low testosterone can coexist with obesity and diabetes; targeted evaluation and management may help. ^[11]
• Lifestyle steps improved diet quality, regular exercise, quitting smoking, and managing cholesterol and blood pressure can support sexual health and vascular function. ^{[1] [2]}

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When to seek help

• Persistent changes in sexual desire or performance deserve a whole‑picture review: glucose control, medication list, cardiovascular status, and hormone levels. Options like PDE‑5 inhibitors (sildenafil, tadalafil, etc.) are often effective and can be considered if appropriate for your health profile. ^[12]
• Don’t stop metformin on your own; if symptoms started after a dose change, your clinician can help decide whether a trial dose adjustment or alternative therapy is reasonable while addressing more common causes of sexual dysfunction. ^[9]

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Bottom line

Based on authoritative drug information and clinical research, metformin is not commonly associated with sexual side effects such as decreased libido or erectile dysfunction, and improved diabetes control with metformin may help reduce the risk of diabetes‑related sexual problems. If you experience sexual symptoms, it’s more likely due to diabetes itself, other medications, or hormonal and cardiovascular factors, and a targeted evaluation can guide effective treatment. ^{[6] [7] [5] [1] [2] [9] [12] [10]}