Not being able to get or keep an erection is stressful at any time. When it happens while you are travelling in Spain — away from your own doctor, unsure how the healthcare system works, and reluctant to explain the problem in a foreign language — the stress compounds. Erectile dysfunction affects roughly half of all men between the ages of 40 and 70 to some degree, and effective medication exists.[1] Getting a sildenafil prescription in Spain as a tourist is entirely possible, and you do not need to sit in a clinic waiting room to do it.
How Erections Work and What Goes Wrong
An erection is a vascular event — it depends on blood flow. When you become sexually aroused, your brain sends signals through nerves in the spinal cord to the blood vessels in the penis. Those nerve signals trigger the release of a chemical called nitric oxide. Nitric oxide causes the smooth muscle lining the two spongy chambers of the penis (the corpora cavernosa) to relax, allowing blood to rush in and fill them.[2]
As those chambers expand with blood, they press against the veins that normally drain blood away, trapping it inside. The result is a firm erection. The whole process works like a dam — pressure builds only when the inflow valve opens and the outflow gets compressed shut.
Erectile dysfunction happens when any part of this chain is disrupted. The most common cause is reduced blood flow to the penis, often due to the same arterial narrowing that leads to heart disease: high blood pressure, high cholesterol, diabetes, and smoking all damage the lining of blood vessels over time.[3] Nerve damage — from diabetes, prostate surgery, or spinal injury — can interrupt the signals that start the process. Low testosterone reduces sex drive but can also impair the nitric oxide pathway directly. And certain medications, including some antidepressants, blood pressure drugs, and antihistamines, can interfere at various stages.[1]
Psychological factors — performance anxiety, stress, relationship tension, depression — can also cause or worsen ED, sometimes creating a cycle where one episode of difficulty triggers anxiety about the next. However, even in younger men where psychological factors are prominent, there is often an underlying physical contributor. One does not rule out the other.[4]
Symptoms and Signs of Erectile Dysfunction
ED is not an all-or-nothing condition. It exists on a spectrum. Some men cannot achieve any erection at all. Others get a partial erection that is not firm enough for penetration. Many can achieve a full erection but lose it before or during intercourse. Occasional difficulty — after heavy drinking, extreme fatigue, or high stress — is normal and does not constitute ED.[1]
Doctors typically define ED as a persistent or recurrent inability to achieve or maintain an erection sufficient for satisfactory sexual performance, lasting at least three months.[2] That said, if the problem is affecting your wellbeing or your relationship right now — including during a trip — there is no reason to wait three months before seeking treatment.
Sildenafil works within 30 to 60 minutes for most men and remains effective for four to six hours. The medication does not create an erection on its own — sexual arousal is still required.
There are a few signs that ED may point to a broader health issue. If you have also noticed reduced morning erections, that suggests a physical rather than purely psychological cause. ED that develops gradually over months or years is more likely to be vascular. Sudden onset, especially if linked to a specific event or stressor, leans more toward psychological — though a medical evaluation is still warranted.[3]
Prescription Medications for Erectile Dysfunction
Both sildenafil and tadalafil belong to a class of drugs called PDE5 inhibitors. They work by blocking an enzyme (phosphodiesterase type 5) that breaks down the chemical responsible for relaxing smooth muscle in the penis. The result is stronger, longer-lasting blood flow when you are sexually aroused. Neither drug creates arousal — they enhance the body's natural response to it.
Sildenafil (Viagra)
Sildenafil was the first PDE5 inhibitor approved for erectile dysfunction. It works by increasing blood flow to the penis when you are sexually aroused. Clinical trials show that sildenafil produces erections sufficient for intercourse in approximately 70–85% of men with ED, across a range of underlying causes including diabetes and post-prostatectomy.[2] It is best taken on an empty stomach, as a high-fat meal can delay its onset by up to an hour.
Tadalafil (Cialis)
Tadalafil works through the same mechanism as sildenafil but has a significantly longer half-life. A single dose remains active in the body for up to 36 hours, earning it the nickname "the weekend pill." This longer window removes the need to time the dose precisely before sexual activity. Tadalafil is also less affected by food, so it can be taken with or without a meal. Efficacy is comparable to sildenafil, with clinical trials showing successful intercourse in 70–80% of men.[5]
What Spanish Pharmacies Can and Cannot Sell You
This is where many tourists run into a wall. In Spain, sildenafil and tadalafil are classified as prescription-only medications — medicamentos con receta médica. No farmacia in Spain can legally sell you Viagra or Cialis without a valid prescription, regardless of whether the medication was available over the counter in your home country. The UK, for example, reclassified low-dose sildenafil (Viagra Connect, 50 mg) for pharmacy sale in 2018, but that ruling does not apply in Spain. Walking into a Spanish pharmacy and asking for it will result in a polite but firm refusal.[6]
What Spanish pharmacies can offer without a prescription are general supplements — zinc, L-arginine, maca root — sometimes marketed for sexual health. These do not have clinical evidence comparable to PDE5 inhibitors and should not be relied on for treating ED. The pharmacist can also sell condoms, lubricants, and over-the-counter pain relief for any unrelated symptoms. If you already have a valid prescription — either from a Spanish doctor, a receta electrónica privada (private electronic prescription), or a recognized foreign prescription — the pharmacist will dispense the medication with no issues. Generic sildenafil in Spain typically costs between €5 and €20 depending on the dose and quantity.