ED guide
Evidence status: EstablishedWhen ED Tablets (Viagra, Cialis) Stop Working
Why might Viagra or Cialis not work for me?
PDE5 tablets such as sildenafil (Viagra) and tadalafil (Cialis) need sexual stimulation, the right dose and timing, and an erectile mechanism that can respond. Apparent failure is often caused by incorrect use, a counterfeit product, a drug interaction or an untreated cause such as low testosterone, diabetes or poor blood flow. A urologist can check these before moving to other options.
Key fact: PDE5 inhibitors are guideline-supported first-line therapy for many men with erectile dysfunction, unless contraindicated. (European Association of Urology, 2026; page updated )
Private & confidential enquiry. You do not need to call.
Key takeaways
- Check use first: dose, timing, food (for sildenafil), stimulation and whether the product is genuine.
- Persistent failure points to an underlying cause worth assessing, including blood flow, nerves, hormones and other medicines.
- Next options include a different PDE5 inhibitor or schedule, vacuum devices, penile injections, shockwave therapy in selected men and, for severe ED, an implant.
Before deciding a tablet has failed
Dose and timing
Sildenafil is usually taken before sex, and a heavy meal can delay it. Tadalafil acts over a longer window. Ask the prescriber whether your dose and timing suit the medicine.
Stimulation
These tablets support the erection response to sexual stimulation. They do not create an erection on their own.
A genuine product
Tablets bought from unregulated online sellers may be counterfeit or contain the wrong dose. Use a registered pharmacy.
Interactions and safety
Never combine PDE5 tablets with nitrates or nitric-oxide donors. Tell the prescriber about all medicines, heart conditions and low blood pressure.
Enough trials
A prescriber can advise how many attempts to allow before changing dose or medicine. Do not increase a dose yourself.
Causes worth looking for if tablets keep failing
Blood-flow problems
Arterial insufficiency or venous leak can limit the response to tablets.
Learn more →Low testosterone
Confirmed deficiency may reduce desire and response to tablets.
Learn more →Diabetes and nerve damage
Neuropathy and vascular disease can reduce the response.
Learn more →Surgery or other medicines
Pelvic surgery and some medicines affect erections.
Learn more →Options a urologist may discuss next
- Adjusting the PDE5 inhibitor, dose or schedule under medical advice.
- Treating the underlying cause, such as blood sugar, blood pressure or testosterone deficiency.
- Vacuum erection devices and intracavernosal injections, which are established options when tablets are unsuitable or ineffective.
- Low-intensity shockwave therapy for selected men with vasculogenic ED. The EAU recommendation is weak.
- Experimental options such as PRP, stem cells and exosomes, discussed only after assessment. The 2026 European Association of Urology (EAU) guideline says intracavernosal PRP for erectile dysfunction should be used only in a clinical-trial setting.
- A penile implant for severe ED that does not respond to other treatment.
Compare the options
The most appropriate treatment depends on the underlying cause of ED.
| Treatment | Typical candidate | Invasiveness | Number of sessions | Recovery | Primary treatment concept | Clinical assessment required |
|---|---|---|---|---|---|---|
| P-Shot (PRP) | Selected men with organic ED after assessment | Minimally invasive (injection) | Protocol varies; confirmed at assessment | Usually short; instructions given by the clinician | Injected platelet-rich plasma, proposed to support tissue repair | Yes |
| Shockwave / EdSWT | Vasculogenic ED; some partial responders to tablets | Non-invasive (no injection) | Clinic protocol: 12 sessions over about 2 to 3 months | No downtime expected for most men; confirmed by the clinic | Low-intensity shockwaves, proposed to support blood-flow pathways | Yes |
| Stem Cell | Selected men when established options were unsuitable or ineffective | Minimally invasive; may involve cell collection | Individualised; explained at assessment | Depends on the procedure; confirmed by the clinic | Cell-based preparation, proposed to support tissue repair | Yes |
| Exosome | Men asking about an investigational option | Minimally invasive if offered | Not established; confirmed only if offered | Confirmed if offered | Cell-derived vesicles, proposed to support repair signalling | Yes |
| PDE5 medication (e.g. sildenafil, tadalafil) | Many men with ED, unless contraindicated (for example with nitrates) | Non-invasive (tablet) | Ongoing, as needed or daily depending on the medicine | None | Increases the blood-flow response to sexual stimulation | Yes (prescription, with a health check) |
| Penile injections (e.g. alprostadil) | Men for whom tablets are unsuitable or ineffective | Self-injection after training | As needed before sex | None | Medicine injected into the penis to produce an erection | Yes (training and dose setting) |
| Penile implant | Severe or refractory ED after other options | Surgical | One operation | Surgical recovery; instructions given by the surgeon | A device placed in the penis that allows an erection | Yes (surgical assessment) |
A guide for discussion with your urologist, not a ranking or recommendation. Regenerative therapies are experimental or investigational for ED.
Your physician
Dr. Niyazi Umut Özdemir
Urological Surgeon, UZ Clinic Antalya
Responsible for assessment and treatment planning at the clinic, with a clinical focus on male sexual health and penile rehabilitation.
Rated 4.5 on Google (47 reviews, as of 2 Oct 2026)Qualifications
- • Medical education at Ege University
- • Specialisation in urology
- • Turkish Association of Urology board certification
- • Clinical practice in Antalya, Turkey
Clinical focus
- • Erectile dysfunction assessment and treatment planning
- • Penile rehabilitation
- • Vasculogenic (blood-flow related) erectile dysfunction
- • Shockwave therapy, PRP and regenerative approaches
Education and roles
- • Ege University Faculty of Medicine (2000); urology specialisation, Ege University (2005)
- • Head of the Antalya branch, CİSED
Professional memberships
- • Turkish Urological Association
- • Society of Urological Surgery (Ürolojik Cerrahi Derneği)
- • European Association of Urology (EAU)
- • Turkish Andrology Association
- • Aegean Urological Association (Ege Üroloji Derneği)
- • Ankara Urologists Association
Ask the urologist about your case
Send your history and the clinic will advise which options may be relevant. Suitability is decided after medical assessment.
Frequently asked questions
Why is Viagra not working for me?
Common reasons are incorrect timing, a heavy meal with sildenafil, too little stimulation, a counterfeit product, an interaction or an untreated cause such as low testosterone, diabetes or poor blood flow.
Is Cialis better if Viagra does not work?
Some men respond to one PDE5 inhibitor better than another, and tadalafil acts over a longer window. A prescriber decides whether switching is appropriate for your health and medicines.
What can I try if ED tablets do not work?
A urologist may discuss treating the cause, a different schedule, vacuum devices, penile injections, shockwave therapy for selected men, or an implant for severe ED. Regenerative treatments are experimental.
Can I take more tablets if the dose does not work?
No. Do not exceed the prescribed dose. Speak to the prescriber, who can check for interactions and decide whether a change is safe.
Do ED tablets work after prostate surgery or with diabetes?
They may help some men, but response can be lower when nerves or blood vessels are affected. A urologist can advise which options are realistic for your case.
Sources
- EAU Guidelines on Sexual and Reproductive Health: Management of Erectile DysfunctionEuropean Association of Urology, 2026 · Guideline
- Erectile Dysfunction: AUA GuidelineAmerican Urological Association, 2018 · Guideline
Related guides
Send your case for confidential review
You do not need to know which treatment you need. Share a few details and the clinic can advise which options may be relevant to your case.
- 1. Send your caseAbout 2 minutes, private.
- 2. Coordinator contacts youBy WhatsApp, phone or email.
- 3. Doctor assessmentThe urologist decides suitability.
Private & confidential enquiry. You do not need to call.
This page provides general information and does not diagnose ED or decide whether a treatment is suitable for you. Suitability and expected benefit vary between patients and are decided after medical assessment. Treatments described as experimental or investigational are discussed with full informed consent. Seek urgent care for chest pain, new neurological symptoms, penile injury or an erection lasting more than four hours.