SLS Endorsement ED Prescription Explained

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SLS Endorsement ED Prescription: Your UK Guide

Published: 17 October 2026

An SLS endorsement ED prescription refers to a prescription for erectile dysfunction treatment that may be issued under specific NHS arrangements, though most ED prescriptions in the UK are private. Whether you're seeking treatment through the NHS or a private service, licensed oral medicines such as sildenafil (Viagra) and tadalafil (Cialis) are available after a clinical assessment by a UK-registered prescriber [1]. Understanding your options helps you access safe, effective treatment for erectile dysfunction.

What is an SLS endorsement ED prescription?

SLS stands for 'Selected List Scheme', a historical NHS classification that allowed certain medicines to be prescribed on the NHS only in specific circumstances. For erectile dysfunction, NHS prescriptions are generally restricted to men with particular medical conditions such as diabetes, prostate cancer treatment, spinal injury, or severe distress due to ED [2]. Most men in the UK obtain ED treatment through private prescriptions, either from their GP or a registered online pharmacy.

When you request an ED prescription through Cured Pharmacy, our UK-registered prescribers review your medical history, current medications, and health conditions during an online consultation. This ensures the treatment is safe and suitable for you, regardless of whether it would qualify for NHS funding. All our ED medicines are licensed in the UK and dispensed by our GPhC-registered pharmacy (9012511).

If you believe you may be eligible for NHS treatment, speak to your GP. They can assess whether your circumstances meet the criteria and issue an NHS prescription if appropriate. For most men, however, private treatment offers a convenient, affordable alternative with the same high clinical standards.

How does an SLS endorsement ED prescription work in practice?

In practice, an SLS endorsement means your GP writes 'SLS' on an NHS prescription to indicate the medicine falls within the permitted criteria. Without this endorsement, pharmacies cannot dispense ED medicines on the NHS for most patients. The criteria are quite narrow: you typically need a diagnosis such as diabetes with neuropathy, treatment for prostate cancer, multiple sclerosis, spinal cord injury, or significant psychological distress documented by a specialist [2].

For the majority of men experiencing erectile dysfunction, a private prescription is the usual route. This does not mean the care is any less rigorous. At Cured Pharmacy, every consultation is reviewed by a UK prescriber who checks your medical history, current medicines (especially nitrates, alpha-blockers, and other blood-pressure drugs), and any conditions that might make PDE5 inhibitors unsuitable [3][4]. The prescriber ensures there are no dangerous interactions and that the dose is appropriate for you.

Private prescriptions also offer greater choice. You can select from a range of licensed treatments—sildenafil, tadalafil, vardenafil, or avanafil—and choose between generic and branded options to suit your budget and preferences. The clinical assessment is the same whether the prescription is NHS or private; what differs is who pays for the medicine.

Checking your eligibility

If you think you may qualify for an NHS prescription, book a face-to-face appointment with your GP. Bring a list of your current medications and any diagnoses related to the conditions mentioned above. Your GP will assess your medical history and, if appropriate, issue an SLS-endorsed prescription. If you do not meet the NHS criteria, your GP can still issue a private prescription, or you can use a registered online service like Cured Pharmacy for convenience and discretion.

What ED treatments are available on prescription?

All licensed oral treatments for erectile dysfunction in the UK are PDE5 inhibitors. These medicines work by increasing blood flow to the penis when you are sexually aroused; they do not cause an erection on their own [1]. The main options are sildenafil (Viagra), tadalafil (Cialis), vardenafil (Levitra), and avanafil (Spedra). Each has a slightly different onset and duration of action, so your prescriber will help you choose the one that fits your lifestyle.

Sildenafil is usually taken about one hour before sexual activity, with effects lasting around four to six hours. Tadalafil can be taken on-demand (at least 30 minutes before sex, with effects lasting up to 36 hours) or as a lower daily dose for spontaneity. Vardenafil works in about 25 to 60 minutes, and avanafil is the fastest-acting, often effective within 15 to 30 minutes [3][4][5][6]. All require sexual stimulation to work and should be taken no more than once a day (or once daily for the daily tadalafil dose).

Beyond tablets, there are other prescription options. Vitaros is an alprostadil cream applied to the tip of the penis, and Caverject is an alprostadil injection. These are usually reserved for men who cannot use PDE5 inhibitors or have not responded to them [7]. Your prescriber will discuss the full range of treatments during your consultation and recommend the most appropriate option based on your health and preferences.

Understanding SLS endorsement ED prescription costs and access

If you qualify for an NHS prescription with SLS endorsement, you pay the standard NHS prescription charge in England (currently £9.90 per item, or free if you are exempt). In Scotland, Wales, and Northern Ireland, NHS prescriptions are free. However, because the eligibility criteria are strict, most men pay privately for ED treatment [2].

Private prescriptions can be more affordable than many people expect. At Cured Pharmacy, generic sildenafil starts from £0.45 per tablet (£0.36 with first-order code Ednew), and generic tadalafil from £7.95 (£6.36 with code Ednew). Branded Viagra is £37.95 (£30.36 with Ednew), and branded Cialis is £12.00 (£9.60 with Ednew). Other options include Sildenafil 100mg (Teva) at £16.99 (£13.59 with Ednew), Tadalafil 20mg (Teva) at £9.99 (£7.99 with Ednew), Avarante (tadalafil) 10mg at £11.49 (£9.19 with Ednew), Vardenafil at £16.95 (£13.56 with Ednew), and Spedra (avanafil) at £20.95 (£16.76 with Ednew).

Accessing treatment online is straightforward. You complete a confidential health questionnaire, a UK prescriber reviews it, and if approved, your medicine is dispensed and posted in discreet packaging. This process meets the same clinical and legal standards as a face-to-face GP appointment, ensuring your safety and the quality of your care.

Comparing NHS and private routes

The NHS route offers lower cost if you qualify, but appointments can take time and eligibility is limited. Private prescriptions provide faster access, greater choice of treatments, and the convenience of online consultations. Both routes require a proper medical assessment, so the clinical safety is equivalent. Choose the option that best suits your circumstances and budget.

When to see a doctor about erectile dysfunction

Erectile dysfunction can be an early warning sign of cardiovascular disease or diabetes, so it is important to speak to a GP if you are experiencing persistent problems [1][10]. Your doctor will take a full medical history, check your blood pressure, and may arrange blood tests to look for underlying conditions such as high cholesterol, diabetes, or low testosterone. Treating these conditions can sometimes improve erectile function and reduce your risk of heart attack or stroke.

You should see a GP urgently if you develop sudden erectile dysfunction alongside chest pain, breathlessness, or other symptoms of heart disease. Also seek advice if ED is causing significant distress, affecting your relationship, or if you have other symptoms such as reduced libido, fatigue, or mood changes, which might suggest hormonal or psychological causes [2].

Even if you choose to use an online service like Cured Pharmacy, it is still worth having a general health check with your GP, especially if you have not had one recently or if you have risk factors such as smoking, high blood pressure, obesity, or a family history of heart disease. Erectile dysfunction is common—affecting around half of men aged 40 to 70 to some degree—and is very treatable, but it should prompt a broader look at your overall health [10].

Safety and interactions with SLS endorsement ED prescription medicines

PDE5 inhibitors are safe for most men, but they are not suitable for everyone. You must never take them if you use nitrate medicines (such as GTN spray, isosorbide mononitrate, or isosorbide dinitrate) for angina, or nicorandil, riociguat, or recreational drugs known as 'poppers' (amyl or alkyl nitrites). Combining these with a PDE5 inhibitor can cause a dangerous drop in blood pressure [3][4][5][6].

If you take alpha-blockers for an enlarged prostate or high blood pressure (such as doxazosin, tamsulosin, or alfuzosin), you may still be able to use a PDE5 inhibitor, but your prescriber will start you on the lowest dose and ensure you are stable on the alpha-blocker first. Some medicines that affect liver enzymes—such as ritonavir, cobicistat, ketoconazole, itraconazole, or clarithromycin—can raise PDE5 levels in your blood, requiring dose adjustments or making some PDE5 inhibitors unsuitable. Always declare every medicine, supplement, and recreational substance you use during your consultation [12].

PDE5 inhibitors are also not suitable if you have very low blood pressure, severe heart failure, unstable angina, or have had a recent heart attack or stroke. If you have a history of sudden vision loss (non-arteritic anterior ischaemic optic neuropathy, or NAION) or certain inherited eye conditions, your prescriber will need to assess the risks carefully. During your consultation, be honest about your health and medications so your prescriber can ensure the treatment is safe for you.

What to do if you experience side effects

Common side effects of PDE5 inhibitors include headache, flushing, indigestion, and nasal congestion. These are usually mild and short-lived [3][4]. If you experience an erection lasting more than four hours (priapism), sudden loss of vision or hearing, or chest pain during sex, seek urgent medical help. Stop taking the medicine and contact your prescriber if side effects are troublesome or persistent. Never adjust your dose without advice.

Scientific References

1. NHS. (n.d.). Erectile dysfunction (impotence). NHS website. https://www.nhs.uk/conditions/erection-problems-erectile-dysfunction/ [accessed 17 October 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 17 October 2026]
3. Joint Formulary Committee. (n.d.). Sildenafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/sildenafil/ [accessed 17 October 2026]
4. Joint Formulary Committee. (n.d.). Tadalafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/tadalafil/ [accessed 17 October 2026]
5. Feldman, H. A., Goldstein, I., Hatzichristou, D. G., Krane, R. J., & McKinlay, J. B. (1994). Impotence and its medical and psychosocial correlates: Results of the Massachusetts Male Aging Study. Journal of Urology, 151(1), 54–61. https://pubmed.ncbi.nlm.nih.gov/8254833/ [accessed 17 October 2026]
6. Electronic Medicines Compendium. (n.d.). Summaries of Product Characteristics and Patient Information Leaflets. https://www.medicines.org.uk/emc/ [accessed 17 October 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.