Invicorp Side Effects: What You Need to Know

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Invicorp Side Effects: A UK Pharmacist's Guide

Published: 14 November 2026

Invicorp side effects are an important consideration if you're exploring injection treatments for erectile dysfunction (ED). Invicorp is a prescription-only dual-chamber injection containing alprostadil and aviptadil, used when oral tablets haven't worked or aren't suitable. This guide explains how Invicorp works, the side effects you might experience, who it may suit, and how it compares with tablet treatments available at Cured Pharmacy.

What is Invicorp and how does it work?

Invicorp is a prescription-only injection for erectile dysfunction that combines two active ingredients: alprostadil (a prostaglandin) and aviptadil (a vasoactive intestinal polypeptide). Unlike oral tablets such as sildenafil or tadalafil, which are taken by mouth and require sexual stimulation to work, Invicorp is injected directly into the side of the penis using a very fine needle about 5–20 minutes before sexual activity[7].

The injection works by relaxing the smooth muscle in the blood vessels of the penis, increasing blood flow and producing an erection regardless of sexual arousal. This mechanism makes Invicorp particularly useful for men who have not responded to oral PDE5 inhibitors (such as Viagra or Cialis), or who cannot take them due to contraindications such as nitrate use[2][7].

Invicorp is administered via intracavernosal injection, meaning the medicine is delivered directly into the corpus cavernosum (the erectile tissue). The dual-action formula is designed to improve effectiveness and reduce the dose of alprostadil needed, which may help minimise some side effects. However, because it is an injection, it requires proper training from a healthcare professional before use, and careful technique to avoid complications.

Common invicorp side effects and how to manage them

The most frequently reported invicorp side effects include pain at the injection site, which affects many users to some degree. This discomfort is usually mild to moderate and tends to improve with experience and correct injection technique[7]. Other common side effects include penile pain during or after the erection, bruising or bleeding at the injection site, and a feeling of warmth or tingling in the penis.

Headache, dizziness, and flushing can also occur, though these are generally less common with injections than with oral tablets. Some men notice small lumps or nodules forming under the skin of the penis (fibrosis) with repeated use, or a slight curvature of the penis (Peyronie's disease). These structural changes are more likely if injections are given too frequently or in the same spot[7].

To minimise side effects, it's essential to rotate injection sites, use the correct dose prescribed by your doctor, and follow the technique you were taught. Never inject more frequently than recommended (usually no more than three times per week, with at least 24 hours between doses). If pain persists, bruising is severe, or you notice any lumps or changes in penile shape, contact your GP or prescriber promptly for review.

Serious side effects requiring urgent attention

The most serious invicorp side effect is priapism—an erection lasting longer than four hours. Priapism is a medical emergency because prolonged erection can damage the erectile tissue permanently, leading to future ED[7]. If your erection lasts more than two hours, seek medical advice immediately; if it continues beyond four hours, go to A&E or call 999.

Other rare but serious reactions include signs of infection at the injection site (increasing redness, warmth, swelling, or pus), severe allergic reactions (rash, swelling of the face or throat, difficulty breathing), or sudden severe pain in the penis. Any of these symptoms require same-day medical assessment. Always keep the contact details of your prescriber and local A&E department to hand when using Invicorp.

Who might consider Invicorp instead of tablets?

Invicorp and other alprostadil injections are typically considered second-line treatments for ED, meaning they are usually tried after oral tablets have not worked or are unsuitable[2][8]. Men who do not respond adequately to sildenafil, tadalafil, vardenafil, or avanafil—even at the highest licensed doses—may benefit from an injection because it works via a different mechanism and does not rely on the same biochemical pathway.

Invicorp may also suit men who cannot take oral PDE5 inhibitors due to contraindications. For example, if you take nitrates for angina (such as GTN spray or isosorbide mononitrate), nicorandil, or riociguat, oral ED tablets are absolutely contraindicated because the combination can cause a dangerous drop in blood pressure[3][4]. Injections like Invicorp work differently and do not share this interaction, making them a safer option in these cases.

Additionally, some men prefer injections because the effect is more predictable and does not depend on sexual stimulation, meal timing, or alcohol intake. However, the need for self-injection, the risk of priapism, and the potential for penile pain or fibrosis mean that injections are not first-choice for most men. A thorough discussion with a GP or specialist is essential to weigh the benefits and risks, and training in correct injection technique is mandatory before starting treatment[2][7].

Is Invicorp available on the NHS?

Invicorp is a prescription-only medicine in the UK, and NHS availability is limited. The NHS generally restricts prescribing of ED treatments, including injections, to certain groups of men—for example, those with specific medical conditions such as diabetes, prostate cancer treatment, spinal injury, or other causes of ED that significantly affect quality of life[2]. Even within these groups, access can vary by local Clinical Commissioning Group (CCG) or Integrated Care Board (ICB) policies.

In practice, most men who wish to try Invicorp will need to see a specialist (such as a urologist or sexual health consultant) for assessment and training. Some NHS trusts offer alprostadil injections, but waiting times can be long. Private prescriptions are an alternative, though Invicorp and similar injection treatments tend to be more expensive than oral tablets, and ongoing costs can add up, especially if used regularly.

If you are considering Invicorp, start by discussing your ED with your GP. They can assess whether you meet NHS criteria, refer you to a specialist if appropriate, or discuss private options. It's important to have a full assessment to rule out underlying health conditions—such as cardiovascular disease or diabetes—that may be contributing to ED and require treatment in their own right[1][2].

Private prescription and training requirements

If you obtain Invicorp on a private prescription, you will still need proper training before using it at home. This training is usually provided by a specialist nurse or doctor and covers how to prepare the injection, choose the correct injection site, inject safely, and what to do if side effects occur. You will also be taught how to recognise priapism and when to seek emergency help[7].

Never attempt to use Invicorp or any other penile injection without this training. Incorrect technique can lead to serious complications, including scarring, infection, or prolonged erection. Your prescriber will also determine the correct starting dose and adjust it based on your response, so follow-up appointments are an important part of safe treatment.

How do invicorp side effects compare with tablet side effects?

When comparing invicorp side effects with those of oral ED tablets, the key difference lies in the nature and location of the side effects. Oral PDE5 inhibitors such as sildenafil, tadalafil, vardenafil, and avanafil commonly cause headache, flushing, indigestion, nasal congestion, and sometimes visual disturbances (a blue tinge to vision with sildenafil)[3][4][5][6]. These side effects are usually mild and short-lived, and many men find they lessen with continued use.

In contrast, invicorp side effects are more localised to the penis. Penile pain, injection-site discomfort, bruising, and the risk of fibrosis or curvature are specific to injections and do not occur with tablets[7]. However, systemic side effects such as headache and dizziness are less common with Invicorp than with oral tablets, because the medicine acts locally rather than circulating throughout the body.

The risk of priapism is significantly higher with injections than with tablets. While prolonged erection can occur with oral PDE5 inhibitors, it is rare; with Invicorp and other alprostadil injections, the risk is much more substantial, especially if the dose is too high or injections are used too frequently[7]. This makes careful dose titration and adherence to usage guidelines critical. Overall, tablets are generally better tolerated and more convenient for most men, which is why they remain the first-line treatment for ED[2][8].

Oral ED tablets available at Cured Pharmacy

If you're exploring alternatives to Invicorp, Cured Pharmacy offers a full range of licensed oral ED treatments, all available after a confidential online consultation reviewed by a UK prescriber. Sildenafil (generic Viagra) is available from £0.45 per tablet (£0.36 with first-order code Ednew), and tadalafil (generic Cialis) from £7.95 (£6.36 with code Ednew). Both are highly effective PDE5 inhibitors used by millions of men worldwide[9].

Branded options include Viagra at £37.95 (£30.36 with code Ednew) and Cialis at £12.00 (£9.60 with code Ednew). For men seeking faster onset, Spedra (avanafil) works in as little as 15–30 minutes and costs £20.95 (£16.76 with code Ednew)[6][11]. Vardenafil (generic Levitra) is also available at £16.95 (£13.56 with code Ednew), and Teva-branded generics offer additional choice.

All these tablets require sexual stimulation to work, are taken by mouth, and have a well-established safety profile. They are not suitable if you take nitrates, nicorandil, or certain other medicines, and your prescriber will check your medical history and current medications during the consultation. For most men, oral tablets are the most convenient, effective, and well-tolerated first-line treatment for ED[2][8]. If tablets have not worked for you, or if you have questions about moving to an injection, discuss this with your GP or a specialist.

How to get started with Cured Pharmacy

Getting treatment at Cured Pharmacy is straightforward. Complete a short online consultation covering your medical history, current medications, and any other health conditions. A UK-registered prescriber reviews every consultation to ensure the treatment is safe and suitable for you. If approved, your medicine is dispensed by our GPhC-registered pharmacy (9012511) and delivered discreetly to your door.

You can choose from a wide range of ED tablets, with options to suit different budgets, preferences, and lifestyles. Use code Ednew on your first order for a discount. If you have any questions, our pharmacist-led support team is available to help. Remember, ED can be an early warning sign of cardiovascular disease or diabetes, so if you're experiencing ED for the first time, it's important to see your GP for a full health check[1][2].

Scientific References

1. NHS. (n.d.). Erectile dysfunction (impotence). NHS website. https://www.nhs.uk/conditions/erection-problems-erectile-dysfunction/ [accessed 14 November 2026]
2. National Institute for Health and Care Excellence. (n.d.). Erectile dysfunction. Clinical Knowledge Summaries. https://cks.nice.org.uk/topics/erectile-dysfunction/ [accessed 14 November 2026]
3. Joint Formulary Committee. (n.d.). Sildenafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/sildenafil/ [accessed 14 November 2026]
4. Joint Formulary Committee. (n.d.). Alprostadil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/alprostadil/ [accessed 14 November 2026]
5. European Association of Urology. (n.d.). EAU Guidelines on Sexual and Reproductive Health. https://uroweb.org/guidelines/sexual-and-reproductive-health [accessed 14 November 2026]
6. Goldstein, I., Lue, T. F., Padma-Nathan, H., Rosen, R. C., Steers, W. D., & Wicker, P. A. (1998). Oral sildenafil in the treatment of erectile dysfunction. New England Journal of Medicine, 338(20), 1397–1404. https://pubmed.ncbi.nlm.nih.gov/9580646/ [accessed 14 November 2026]

Information on this page is for educational purposes only and is not medical advice. Prescription treatments require clinical assessment by a UK-registered prescriber. Always consult a qualified healthcare professional before starting or changing any medication.

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