Erectile dysfunction: causes, treatments and when to seek help

Erectile dysfunction, ED for short, is one of the most common reasons a man in his forties, fifties or sixties finally books a GP appointment, and one of the most underdiscussed reasons he puts it off for three years first.

As a GP I see it every week, and in almost every case the conversation is shorter, less embarrassing and more productive than the patient feared.

This guide walks you through what ED actually is, what causes it, what tests your GP will arrange, which treatments are licensed in the UK and when to push back if the first option does not suit you.

What counts as erectile dysfunction?

Clinically, ED is the persistent inability to achieve or maintain an erection sufficient for satisfactory sexual activity, lasting at least three months. Occasional difficulty after a heavy night, a stressful week or a new partner is not ED, it is being human. Genuine ED is consistent, reproducible across partners and situations, and usually progressive. The NHS erection problems page uses a similar definition and is a reassuring place for patients to start.

Is ED mostly psychological or physical?

In men under forty, psychological factors, including performance anxiety, relationship tension and depression, dominate. From forty five onwards, vascular causes account for the majority. The giveaway signs of a physical cause are:

• Gradual onset over months to years.
• Loss of morning and nocturnal erections, not only partnered ones.
• Reduced firmness even with reliable stimulation.
• Coexisting risk factors such as hypertension, diabetes, dyslipidaemia, smoking, obesity or sleep apnoea.

A psychological pattern looks different: sudden onset, preserved morning erections, situational variation and a clear emotional trigger. Most men sit somewhere in between and the consultation teases out the mix.

Why your GP will ask about your heart

ED often predates a cardiac event by three to five years.

A man presenting with new onset ED at fifty has a meaningfully increased risk of coronary disease, and that is the single best reason to see a GP rather than order tablets off a random website.

At minimum your clinician should:

• Measure blood pressure in both arms.
• Check fasting lipids, glucose or HbA1c, and kidney and liver function.
• Ask about morning testosterone, especially if libido is low.
• Calculate a QRISK3 score and discuss cardiovascular prevention.
• Screen for depression and alcohol intake.
• Ask about snoring and daytime sleepiness pointing to obstructive sleep apnoea.

The patient.info erectile dysfunction overview summarises the assessment protocol clearly for non-clinicians.

Medicines that commonly cause ED

Before starting any ED treatment it is worth reviewing the list of usual culprits:

• Thiazide diuretics such as bendroflumethiazide.
• Older beta blockers, particularly atenolol and propranolol.
• Spironolactone.
• Finasteride and dutasteride, although incidence is low.
• SSRIs and SNRIs, with sertraline and paroxetine the usual offenders.
• Opioids, long term use suppresses testosterone.
• Recreational cocaine, alcohol binges and heavy cannabis use.

A thoughtful medication review alone resolves ED for a meaningful minority of patients. Never stop a prescribed medicine without discussion, but do raise it.

Lifestyle changes that actually move the needle

I understand the eye roll when a GP recommends lifestyle change for something a patient would prefer to treat with a tablet. The evidence for ED specifically is strong though:

• Stopping smoking improves erectile function within six to twelve months.
• Losing ten percent of body weight restores function in roughly a third of obese men.
• 150 minutes of moderate exercise a week is comparable to a low dose PDE5 inhibitor in mild cases.
• Reducing alcohol below fourteen units a week improves both erections and mood.
• Treating sleep apnoea with CPAP restores erectile function in many men where testosterone was suppressed by fragmented sleep.

These work best alongside, not instead of, medication in moderate to severe cases.

Which PDE5 inhibitor is right for you?

Four phosphodiesterase-5 inhibitors are licensed in the UK. Each has a slightly different profile and your GP or online prescriber will match the drug to your pattern of sex, speed of onset required and coexisting conditions.

Sildenafil

Sildenafil, the generic of Viagra, is the default first line. Onset around thirty to sixty minutes, duration four to six hours, take on an empty stomach for reliable absorption. Doses 25mg, 50mg, 100mg. Works well for planned intercourse.

Tadalafil

Tadalafil, generic of Cialis, has a much longer half life giving a thirty six hour window of responsiveness. Often preferred by men who prefer spontaneity. Also available as a low dose 2.5mg to 5mg daily regimen which some men find transformative. Dose neutral to food.

Vardenafil

Vardenafil sits between sildenafil and tadalafil in half life. Useful for men who get facial flushing or headaches on sildenafil. Similar meal effect to sildenafil.

Avanafil

Avanafil in Spedra has the fastest onset of any licensed PDE5 inhibitor, fifteen to thirty minutes, and a cleaner side effect profile. Often the best option for men who dislike the flush of sildenafil or the muscle ache of tadalafil.

The BNF treatment summary for erectile dysfunction lists all four with doses, cautions and interactions.

When the first tablet does not work

Roughly a third of men do not respond to the first PDE5 inhibitor they try. Before concluding it has failed:

1. Confirm you have tried the maximum licensed dose.
2. Confirm you have taken it at least six times with adequate sexual stimulation, on an empty stomach if sildenafil or vardenafil.
3. Confirm alcohol was moderate and you were not exhausted.
4. Try switching class, for example sildenafil to tadalafil, which resolves another third of apparent failures.
5. Consider daily low dose tadalafil for chronic rather than on demand use.

If two agents at maximum dose fail, referral to a urology or andrology clinic is warranted. Second line options include intracavernosal alprostadil injection, intraurethral alprostadil, vacuum devices and, in selected cases, penile prosthesis surgery.

Erectile dysfunction and premature ejaculation together

Around a third of men with ED also report premature ejaculation, PE. The two can feed each other, with rushed intercourse leading to loss of erection and vice versa. Licensed UK treatment for PE is dapoxetine, prescribed after assessment. You can read more on the premature ejaculation category page. Combining dapoxetine with a PDE5 inhibitor is common and safe under prescriber supervision.

The elephant in the consulting room: relationships and mental health

ED rarely sits in isolation from the rest of a man's life. Depression, anxiety and relationship strain are both causes and consequences.

A proper consultation gives space to raise these and offers signposting to talking therapies where relevant.

Your GP or online prescriber can refer to NHS Talking Therapies in England or the equivalent in Scotland, Wales and Northern Ireland, and your partner should be part of the conversation where possible.

What a responsible online ED service looks like

The erectile dysfunction treatment page sets out how we assess new consultations. In short we expect a full medical history, a review of current medicines, a blood pressure reading within the last twelve months, and ongoing prescriber availability. We will decline treatment if safety signals appear, and we will share the outcome with your NHS GP at your request. That is what the MHRA distance selling logo is meant to guarantee.

Red flags to bring forward urgently

• New chest pain with exertion or sex.
• Sudden loss of erection with simultaneous groin or perineal pain, which may indicate vascular dissection.
• Priapism lasting more than four hours, which is a urological emergency, phone 999.
• Sudden visual or hearing disturbance after a PDE5 inhibitor.
• Any collapse or faint after combining a PDE5 inhibitor with an unknown substance, disclose honestly.

The takeaway

Erectile dysfunction is common, treatable and often the visible tip of a cardiovascular iceberg that your GP would much rather catch now than after a heart attack.

The licensed UK options work, they are affordable, and they are safer by orders of magnitude than anything purchased outside a GPhC registered pharmacy. Book the appointment.

The conversation takes ten minutes and you will wonder why you waited.

For a deeper dive on counterfeits and why the grey market is so dangerous, see why unprescribed ED pills are so risky. For safe ordering in general, ordering medicine online safely covers the wider rules.

Daily versus on demand PDE5 therapy

Most men start with on demand treatment, taking a tablet thirty to sixty minutes before planned activity. For men who have sex more than twice a week, or who find the planning itself anxiety provoking, low dose daily Cialis once a day (tadalafil 2.5mg to 5mg) is often life changing. Steady state levels mean spontaneity returns. It also treats benign prostatic hyperplasia symptoms in men who have both conditions, a useful two for one. Side effects are generally milder at the lower dose, although back and leg ache occur in around five percent of users.

Testosterone and ED: the common misconception

Many men hope their ED is a testosterone deficiency problem, perhaps because testosterone sounds more flattering than blocked arteries.

In fact fewer than ten percent of ED cases are driven primarily by low testosterone, and PDE5 inhibitors work regardless of testosterone level.

A morning total testosterone is worth measuring if libido is flat, mood is low or you have other signs of hypogonadism.

Where it is genuinely low and symptomatic, testosterone replacement is a specialist decision, not something to self source from an online bodybuilding pharmacy.

The counterfeit testosterone market carries all the same risks as the counterfeit ED market, plus the added bonus of cardiovascular thrombosis from unreliable dosing.

Partner perspectives matter

ED affects two people, not one. Partners often report feeling blamed, rejected or worried about their own attractiveness.

Bringing them into the conversation early short circuits a lot of relationship damage.

Psychosexual therapy through Relate or an NHS referral can be transformative when the psychological element is prominent. Medication plus therapy outperforms medication alone in most randomised trials.

Do not underestimate how much practical difference an open conversation at home makes.

What about pumps, bands and other devices?

Vacuum erection devices, sometimes called penis pumps, are a legitimate second line option on the NHS and are particularly useful after prostate surgery.

They look unappealing but the evidence is reasonable. Constriction rings worn at the base of the penis can prolong a partial erection and are safe when used correctly.

Over the counter herbal remedies, by contrast, range from mildly placebo to frankly dangerous.

Several have been found by MHRA to contain undeclared sildenafil at unknown doses, which is doubly bad because the man believes he is taking a herbal product and may be on a nitrate.

ED after prostate surgery

Radical prostatectomy damages the cavernous nerves and a proportion of men develop ED afterwards.

Early penile rehabilitation with daily low dose tadalafil, starting within weeks of surgery, improves long term recovery.

Second line options include intracavernosal alprostadil and, in persistent cases, penile prosthesis implantation by a specialist andrologist.

This is a conversation for the urology team, not an online prescriber, but knowing the pathway helps patients advocate for themselves.

When to refer to a specialist

Most ED is managed entirely in primary care. Referral to urology or andrology is warranted for:

• Failure of two PDE5 inhibitors at maximum dose.
• Suspected Peyronie's disease with painful curvature.
• Young men with sudden onset suggesting vascular or neurological cause.
• Testosterone replacement decisions in men with unusual biochemistry.
• Post prostatectomy rehabilitation.

A good GP or online prescriber will make the referral rather than try to solve everything at arm's length.