> ## 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. # Vitaros (alprostadil cream) > How alprostadil cream works for erectile dysfunction, the UK authorisation, and the local side effects reported in trials. Alprostadil is a copy of prostaglandin E1, a substance the body makes naturally that widens blood vessels. Vitaros is the cream form — applied to the tip of the penis rather than swallowed or injected — so it acts on the blood vessels directly at the site. It relaxes the smooth muscle of the corpora cavernosa and widens the cavernosal arteries feeding them, increasing blood flow into the erectile tissue. Because it acts directly on the blood vessels, it does not depend on the signalling pathway used by PDE5 tablets such as sildenafil or tadalafil. ## What it is Alprostadil, chemically identical to prostaglandin E1. Cream, 3 mg/g, applied at the tip of the penis on demand. Vitaros holds national authorisations rather than a centralised EU one; the details on this page come from the United Kingdom authorisation (MHRA, holder The Simple Pharma Company Limited). It is not listed in the Spanish medicines register, so availability differs markedly from one European country to another. It has been authorised in EU countries for erectile dysfunction as a cream since 2014. Because it is a cream rather than a tablet, it is used mainly when tablets are unsuitable. ## How it works Alprostadil is applied to 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, so blood flow into the erectile tissue rises. Because it acts directly on the blood vessels, it does not depend on the signalling pathway used by PDE5 tablets such as sildenafil or tadalafil. A different pathway from oral erectile dysfunction tablets. Acts on the blood vessels at the site, not system-wide. Considered when oral PDE5 tablets aren't the right fit or aren't allowed. ## What the studies reported An integrated analysis of alprostadil topical cream in 1,732 patients was published in [Urology 2006](https://pubmed.ncbi.nlm.nih.gov/16904458/) (PMID 16904458\). The cream studies ran for 12 weeks; the IIEF changes reported are described by the authors as small in absolute terms, with SEP2 and SEP3 improvements described as slight though statistically significant. A related intraurethral pellet form of alprostadil was studied in the transurethral pivotal trial reported in [N Engl J Med 1997](https://pubmed.ncbi.nlm.nih.gov/8970933/) (PMID 8970933, MUSE Study Group) — mild penile pain was its most common side effect, occurring after 10.8% of treatments, with in-clinic low blood pressure in 3.3% of men and no priapism or penile fibrosis reported. Every NCT identifier in Hi-Doctor's evidence base links to its ClinicalTrials.gov record; a readout is not the same as peer-reviewed publication. ## What has been reported | Effect | Frequency reported | | ------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------- | | Penile burning, penile pain, penile erythema, genital pain and discomfort | Common in EU product information | | Withdrawal from the trial due to side effects | 30% in the 300 microgram group vs. 20% in the 200 microgram group | | Priapism (erection lasting more than 6 hours) | Uncommon — 0.06% (1 patient) across two 3-month studies, 0.4% (5 patients) in a study lasting more than 6 months | | Dizziness and fainting (symptomatic low blood pressure) | 0.4%, 0.4% and 0.5% of patients on the 100, 200 and 300 microgram doses | | Vulvovaginal burning and vaginitis in a female partner | Common in EU product information | An erection lasting 4 hours or more is priapism, and it is a medical emergency. Untreated priapism can permanently damage erectile tissue. Patients are advised not to drive or do hazardous tasks until they know how they react to the cream. ## Who it is not suitable for A doctor assesses history and current medication before prescribing, and decides whether Vitaros or another sexual health option is appropriate. For men for whom an injection is more suitable, [Caverject](/library/medicines/caverject) is the alprostadil intracavernosal injection form, reviewed separately. ## Common questions Vitaros is alprostadil 3 mg/g cream applied to the tip of the penis. Alprostadil is chemically identical to prostaglandin E1, a substance the body makes naturally. It relaxes the smooth muscle of the corpora cavernosa and widens the arteries feeding them, increasing blood flow into the erectile tissue. Because it acts locally, it does not depend on sexual arousal in the same way PDE5 tablets do. Vitaros is a cream rather than a tablet, so it is used mainly when tablets are unsuitable. It works through a different pathway from PDE5 inhibitors such as [sildenafil](/library/medicines/viagra) or [tadalafil](/library/medicines/tadalafil). Because it acts on the blood vessels at the site, the main side effects are also local. Penile burning, penile pain, penile erythema, genital pain and discomfort are all listed as common in the EU product information. Vulvovaginal burning and vaginitis in a female partner are also listed as common. Dizziness and fainting occurred in 0.4% to 0.5% of patients across the three dose groups in the phase 3 studies. Priapism (an erection lasting more than 6 hours) was seen in 1 patient (0.06%) across two 3-month studies, and in 5 patients (0.4%) in a study lasting more than 6 months. An erection lasting 4 hours or more is a medical emergency — untreated priapism can permanently damage erectile tissue. Vitaros holds national authorisations rather than a centralised EU one. It has been authorised in EU countries for erectile dysfunction as a cream since 2014. It is not listed in the Spanish medicines register, so availability differs from one European country to another. ## How Hi-Doctor handles it The questionnaire covers symptoms, cardiovascular history, current medication and allergies — see how [eligibility works](/essentials/how-it-works). Certain answers, such as nitrate medication, rule treatment out entirely because of a dangerous interaction; see [safety](/essentials/safety) for how these checks run. Vitaros is one of several [sexual health options](/essentials/treatments) a doctor may consider. The consultation cost is set out on [pricing](/essentials/pricing); the medicine itself is paid separately at a pharmacy. ## 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.