> ## Documentation Index
> Fetch the complete documentation index at: https://docs.hi-doctor.ai/llms.txt
> Use this file to discover all available pages before exploring further.
# Alprostadil for erectile dysfunction
> How alprostadil cream, injection and urethral pellet work, EU authorisation dates, and the side effects reported in trials.
Alprostadil is a man-made copy of the natural signalling substance prostaglandin E1, applied to or injected into the penis to widen the blood vessels directly so blood flows in and produces an erection. Unlike oral tablets, it acts locally in the erectile tissue rather than through the whole body, which is why its main side effects are also local — burning, pain or redness where it is applied, and rarely an erection that lasts too long needing urgent medical attention.
## What it is
**Active ingredient:** Alprostadil · **Dosage form on catalogue:** Cream 3 mg/g, on demand
Alprostadil is a prostaglandin E1 medicine that directly dilates the blood vessels of the penis. It's considered when oral PDE5 inhibitors are ineffective or contraindicated. It's given as a urethral cream, a urethral pellet, or an intracavernous injection — each route has its own efficacy and tolerability profile.
It is indicated for adult men whose erectile dysfunction is unsuited to, or not helped by, oral tablets.
## How it works
Alprostadil is chemically identical to prostaglandin E1, a signalling substance the body already makes. It is not swallowed — it is placed into or onto the penis itself, so it acts on the erectile tissue at the site rather than circulating through the whole body first.
It relaxes the smooth muscle of the corpora cavernosa — the two spongy cylinders that run the length of the penis — and widens the cavernosal arteries feeding them. Blood flow into the erectile tissue rises, and that increase in flow is what produces rigidity.
## EU authorisation
Alprostadil has been authorised for use in the EU since **29 November 1994**, so a licensed doctor can prescribe it when it is clinically appropriate.
* **AEMPS CIMA — Caverject 20 microgramos** (alprostadil, intracavernosal injection), reg. 60535, first authorised in Spain 29 November 1994, indicated for erectile dysfunction.
* **AEMPS CIMA — Virirec 3 mg/g crema** (alprostadil topical), reg. 78357, first authorised April 2014; the same cream was approved via the EU decentralised procedure as Vitaros in 2013.
## What the studies reported
The IIEF changes reported for the cream are small in absolute terms, and the authors describe the SEP2 and SEP3 improvements as slight though statistically significant. Those studies ran for 12 weeks and cover the topical cream only, not the injected or intraurethral forms.
| Source | What it studied |
| ---------------------------------- | ------------------------------------------------------------------ |
| *Urology* 2006 (PMID 16904458) | Integrated analysis of alprostadil topical cream in 1,732 patients |
| *N Engl J Med* 1996 (PMID 8596569) | Efficacy and safety of intracavernosal alprostadil |
| *N Engl J Med* 1997 (PMID 8970933) | Transurethral alprostadil, MUSE Study Group |
## What has been reported
| Effect | Route | Reported frequency |
| --------------------------------------------------------- | --------------- | --------------------------------------------------------------------------------------------------------------------------------------------- |
| Penile burning, pain, redness; genital pain/discomfort | Cream | Common (EU product information). Trial withdrawal rate 30% at 300 mcg vs 20% at 200 mcg |
| Penile pain | Injection | Very common (EU product information). Six-month self-injection study: mild pain in 50% of men at some point, but after only 11% of injections |
| Prolonged erection (4–6 h) | Injection | 4% of patients (EU product information); self-injection study 5% |
| Priapism (>6 h) | Injection | 0.4% (EU product information); self-injection study 1% |
| Priapism | Cream | Uncommon (EU product information). 0.06% across two 3-month studies; 0.4% in a study lasting more than 6 months |
| Penile fibrosis (angulation, nodules, Peyronie's disease) | Injection | 3% in clinical trials, rising to about 8% in an 18-month self-administration study. Haematoma 3%, bruising 2% |
| Dizziness / fainting (low blood pressure) | Cream | 0.4%, 0.4% and 0.5% at the 100, 200 and 300 mcg doses in the phase 3 studies |
| Vulvovaginal burning, vaginitis (female partner) | Cream | Common (EU product information) |
| Penile pain | Urethral pellet | Most common effect, after 10.8% of treatments; in-clinic low blood pressure in 3.3% of men; no priapism or fibrosis reported |
An erection lasting **4 hours or more is priapism**, and it is a medical emergency. Untreated priapism can permanently damage erectile tissue.
## Who it is not suitable for
The harvest does not set out a formal contraindication list for alprostadil beyond the effects above. What is documented: patients are advised not to drive or do hazardous tasks until they know how they react, because of the dizziness and fainting reported in cream trials, and a partner may experience vulvovaginal burning or vaginitis. The reviewing doctor weighs your full history before deciding whether alprostadil is appropriate.
## How Hi-Doctor handles it
If a doctor decides alprostadil is right for you, they explain the chosen route and how to use it.
Correct technique matters, and your doctor explains the protocol and the warning signs to watch for.
The consultation fee is listed on [pricing](/essentials/pricing); the medicine itself is paid separately at a pharmacy.
## Common questions
Alprostadil cream starts working within 5 to 30 minutes of application. The effect lasts long enough for sexual activity. Injection works faster, usually within 5 to 20 minutes. Urethral pellets produce an erection within 5 to 10 minutes in most men.
They work in completely different ways. Alprostadil acts locally on the erectile tissue and does not circulate through the whole body like PDE5 inhibitors, so it avoids systemic side effects such as headache, facial flushing and indigestion. However, alprostadil causes local pain and burning, and carries a risk of priapism (a prolonged erection needing urgent treatment). A doctor weighs both options against your medical history.
Penile pain is the most common side effect across all forms. With the cream, burning, pain and redness are common. With the injection, mild penile pain occurred in 50% of men at some point during a six-month study but only after 11% of injections. With the urethral pellet, mild pain was reported after 10.8% of treatments.
Priapism is an erection lasting 4 hours or more, and it is a medical emergency. Untreated priapism can permanently damage the erectile tissue and lead to lasting erectile dysfunction. In EU product information, priapism occurred in 0.4% of injection patients and 0.06% of cream patients in clinical studies.
Yes. Vulvovaginal burning and vaginitis are listed as common reactions in female partners in the EU product information for the cream.
Yes, if a doctor decides it is appropriate. Alprostadil is considered when PDE5 inhibitors are ineffective or contraindicated. A licensed doctor reviews your full history before deciding.
## Related reading
* [MUSE](/library/medicines/muse) — the same active ingredient, alprostadil, as a urethral pellet
* [Caverject](/library/medicines/caverject) — alprostadil as an intracavernosal injection
* [Tadalafil (Cialis)](/library/medicines/cialis) — an oral alternative when tablets are suitable
* [Erectile dysfunction](/library/conditions/erectile-dysfunction) — the condition this treats
* [How a consultation works](/essentials/how-it-works)
* [Safety and eligibility](/essentials/safety)
## Start a consultation
Answer the sexual health questionnaire and a registered doctor reviews it.
They decide whether treatment is appropriate, which one, and at what dose —
and declining is a normal outcome. See [what it costs](/essentials/pricing)
and [how the review works](/essentials/how-it-works).
This page is reference information, not medical advice and not a prescription.
Whether a medicine is appropriate for you is decided by a registered doctor
after reviewing your consultation.