Erections and sex drive

Changes in erections or sex drive are a fair question, with or without these medicines. First, when to get care.

When to get care

• Now

  If you use an erection medicine and an erection lasts more than 4 hours, get emergency care now.

  This isn't an effect of GLP-1 medicines. The label of tadalafil, a common erection medicine, says to seek emergency treatment.

• Soon

  If your erections, sex drive or energy have changed and aren't coming back, talk to your doctor in the next few days.

  It can be a sign of something worth checking, like high blood pressure, high cholesterol, diabetes or a hormone change.

What's known

On erections, the studies disagree and none proves cause. Some database studies found more erection problems in men on these medicines, with small absolute numbers and other possible explanations. Others saw erections improve along with weight loss.

On sex drive: in a small trial of men with obesity and low testosterone, desire went up on liraglutide and on testosterone gel, with no clear difference between them, measured with a scale that wasn't validated. In healthy men whose testosterone wasn't low, a short placebo-controlled trial saw no change in desire or function.

None of the six US and European labels reviewed list erection problems, low sex drive or testosterone.

A change that doesn't come back deserves a conversation: it can come from blood pressure, cholesterol, diabetes or hormones, which are worth checking anyway.

If you use erection medicines: neither the tadalafil label nor the GLP-1 labels reviewed describe an interaction between them. Nitrates, used for chest pain, must never be combined with erection medicines. On days with vomiting or diarrhea, blood pressure can drop more easily, which also matters with erection and blood pressure medicines.

Planning to have kids? None of the US or European labels asks men to stop these medicines before trying; that rule is for women. The labels say the effect on human fertility is unknown, and studies in male animals found no effect. It's a good question for your doctor.

To take to your appointment

• I've noticed a change in my erections. Is it worth looking into?
• My sex drive has changed. Could it be my health, my weight or the treatment?
• We're thinking about having kids. Does my treatment change anything?