Editorially reviewed by Dr Fatimah Khan, registered with the Pakistan Medical and Dental Council (PMDC no. 104595-P). Editorial medical reviewer; does not prescribe or review patient assessments.
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When might alprostadil injections be considered?
Alprostadil is a medicine used for erectile dysfunction (ED). A clinician may consider an injection treatment when tablets are unsuitable or have not helped. This does not mean an injection is automatically the next step: persistent erection difficulties need assessment of their possible causes and the treatments already tried. The NHS ED guide describes that wider assessment.
Alprostadil acts locally to relax tissue and improve blood flow. This article concerns intracavernosal injection, meaning an injection into erectile tissue. Other presentations, such as urethral products, have their own instructions and availability; they are not interchangeable.
Training is part of the treatment
The UK Caverject product information requires a physician to select the dose through supervised titration. Initial injections are given by medically trained personnel. Home administration requires instruction and an assessment of the patient's ability to use the medicine.
The training covers preparation, hygiene, injection-site rotation, the prescribed amount and disposal. This guide does not provide an injection technique or starting dose. A written article cannot replace observed training.
Before home treatment, ask:
- Who will supervise the initial doses and assess my technique?
- Which exact presentation and equipment will I use?
- What follow-up will check for pain, scarring or a change in response?
- Who should I contact if an erection lasts longer than expected?
Pain and prolonged erections
Injection-related pain, bleeding and bruising can occur. Fibrosis or changes in penile shape are reasons for regular examination. Describing the injection as easy or less painful than expected would minimise experiences that vary between patients.
An erection lasting four hours requires immediate medical assistance, as advised in the Caverject information. Do not wait for a routine appointment or attempt another injection. Your clinician should provide a clear emergency plan before treatment starts.
Who needs particular assessment?
Caverject is unsuitable for some people, including those with conditions predisposing to priapism, certain penile deformities or penile implants, and men for whom sexual activity is medically inadvisable. Medicines affecting bleeding and other health conditions must be discussed. This is not an exhaustive eligibility checklist.
Tablets and specialist treatment
Our Cialis and Viagra comparison explains oral ED medicines. Injection treatment involves a different route and additional training; a comparison should not imply it is universally more effective or appropriate.
Prescrivia is a technology intermediary, not a clinic or medical provider. Independent clinicians determine the appropriate assessment and referral pathway. An online assessment does not guarantee injection treatment, specialist access or a prescription.
General information only, not medical advice. Follow the leaflet for your actual product and discuss decisions with a qualified clinician. See the current clinical, legal and language review statuses for this edition.
Sources
- Pfizer UK Caverject injection SmPC: indication, supervised titration, training, contraindications, fibrosis and prolonged erection.
- NHS guidance on ED assessment and options beyond oral medicines.
Sources checked online on 6 October 2026. UK and US guidance is identified as such; it does not establish availability or prescribing rules across all European countries.