Side effects / Start here

ED treatment safety, know the warning signs.

Side effects, medicine interactions and heart health before treatment. For an erection lasting more than 3 to 4 hours, chest pain, or sudden changes to your sight or hearing, call 999 or go to A&E.

pages in this section

Every page lists its sources and is checked against them. We only cite trusted medical sources such as the NHS, NICE, the MHRA and each medicine's official product information.

Start here1 page

Contacting your prescriberWhen to contact the prescriber who supplied your ED medicine, and how to prepare so you get a useful answer.Checked against its sources

Priority safety content3 pages

Urgent warning signsRare but serious symptoms that need emergency help while taking ED medicines, and where to go.Checked against its sources
Heart health before treatmentWhy your prescriber asks about your heart, blood pressure and other medicines before recommending an ED medicine.Checked against its sources
Medicine and substance interactionsMedicines, drinks and substances that can interact with ED medicines. Always give your prescriber a full list of what you take.Checked against its sources

Symptoms explained2 pages

Common side effectsThe side effects people most often notice with sildenafil and tadalafil. They're usually mild and short-lived.Checked against its sources
Vision and hearing changesTemporary vision changes are a known side effect of sildenafil. Sudden loss of sight or hearing is different and needs urgent help.Checked against its sources