Sildenafil vs Viagra: What Is the Difference?

When you compare erectile dysfunction (ED) treatments, you may come across Viagra and sildenafil. Are they the same thing, or is one more effective than the other? While it may look like you're choosing different medications, sildenafil and Viagra are the same.

Sildenafil is the active ingredient in both medications, while Viagra is the brand name that the company Pfizer gave to sildenafil when it was launched in 1998. They work in the same way and come in similar dosages. Their difference mainly lies in price.

This guide explains the differences between Viagra and sildenafil tablets with guidance on where you can safely purchase these medications in the UK.

Key Takeaways

• Sildenafil and Viagra contain the same active ingredient, sildenafil citrate, and work in the same way to treat erectile dysfunction.
• The main difference is price, where generic sildenafil is usually cheaper than branded Viagra.
• Both medications usually start working within 30 to 60 minutes and remain effective for around 4 to 6 hours.
• Generic sildenafil and standard Viagra require a prescription in the UK, but you can get Viagra Connect 50 mg through a pharmacy without a prescription after a suitability check.

What Are Sildenafil and Viagra?

Sildenafil is a medication in the PDE5 inhibitor class (drugs that widen blood vessels and increase blood flow). It's licensed in the UK to treat erectile dysfunction in men and pulmonary arterial hypertension under a different brand name.

In the late 1980s and early 1990s, scientists at Pfizer's UK research facility developed sildenafil to treat angina (chest pain from reduced blood flow to the heart). The medication had poor results for chest pain, but male clinical trial participants noticed improved erections.

An erection depends on blood flow into the penis. Sildenafil blocks an enzyme called PDE5, which allows blood vessels to relax and blood flow to increase, hence the side effect. However, note that sildenafil doesn't cause erections or heighten desire on its own. You would still need sexual stimulation for it to have any effect.

Viagra is the original brand of sildenafil marketed by Pfizer as the first oral ED medication in the UK. Pfizer held exclusive rights to the pill, but in 2013, other manufacturers got the freedom to produce the same medicine as generic sildenafil.

Similarities Between Viagra and Sildenafil

These erectile dysfunction medications have the following things in common:

• Same Active Ingredient: They contain the medically active ingredient sildenafil citrate.
• Mechanism of Action: Both Viagra and sildenafil belong to the class of PDE5 inhibitors.
• Requirement for Arousal: Neither acts as an aphrodisiac or produces an automatic erection; both require natural sexual stimulation to work.
• Dosage Strengths: They come in standard doses of 25 mg, 50 mg, and 100 mg.
• Timing & Duration: The ED pills take 30 to 60 minutes to become effective and remain active in the body for approximately four to six hours.
• Side Effect Profile: Erectile dysfunction treatments have the same potential side effects, including headaches, facial flushing, indigestion, nasal congestion, and temporary visual tinting (changes in color perception).
• Medical Suitability: Anyone who's eligible to take Viagra is also eligible to take generic sildenafil (and vice versa).
• Health Contraindications: Patients with certain health conditions, such as severe cardiovascular disease, recent stroke or heart attack, low blood pressure, or taking nitrate medications, can't take Viagra or sildenafil.
• Age Requirements: Only adults aged 18 and over can take these medications.

Viagra vs Sildenafil: The Key Differences

The following are the main differences between the two:

Cost

Sildenafil is the generic version, so it's less expensive than branded Viagra. Drug manufacturers didn't fund the original research and can therefore produce the medicine more cheaply, unlike Pfizer.

Appearance

Prescription Viagra is a blue diamond-shaped tablet. Generic sildenafil looks different depending on the manufacturer, but it's often a white or blue pill in a plain round or oval shape. Because Viagra has such a distinct appearance, some people are cautious when buying generic medication. However, the pill should work the same if it comes from a legitimate registered pharmacy.

Availability

Generic sildenafil and standard Viagra both require a prescription, which means you need to go through a consultation with a registered provider before taking the medication.

However, you can get Viagra Connect in the UK without a prescription. It's a 50 mg sildenafil product that the Medicines and Healthcare products Regulatory Agency (MHRA) reclassified from a prescription-only medicine to a pharmacy pill in 2017.

Note that a pharmacist must still check whether Viagra Connect is suitable for you, and they can decline to supply it.

Sildenafil vs Viagra Tablets: Does One Work Better Than the Other?

Viagra and sildenafil work in the same way because they have the same active ingredient and dosages. One is not stronger or more effective than the other at the same dose.

Health regulatory authorities in the UK require generic medications to be bioequivalent to their brand-name counterparts. This means that generic sildenafil must give the same amount of active ingredient to your bloodstream at the same speed as brand-name Viagra.

Which One Should You Choose?

Because both medications rely on the same chemical compound, choosing between them for most people comes down to price and availability.

You can buy either one, depending on what's available at your pharmacy and what you're willing to pay, since the generic version is cheaper. People without a prescription should consider purchasing Viagra Connect through a registered pharmacy.

Sildenafil and Viagra Alternatives

Sildenafil is not the only PDE5 inhibitor available in the UK. There are other medications for eligible patients, including:

• Tadalafil (Cialis): Generic Cialis lasts longer than sildenafil (up to 36 hours), which is why some people call it 'the weekend pill'.
• Vardenafil (Levitra / Staxyn): Works similarly to sildenafil and lasts about four to five hours. Staxyn comes as an orally disintegrating tablet that dissolves on the tongue without water.
• Avanafil (Spedra / Stendra): A newer PDE5 inhibitor that works very quickly, often within 15–30 minutes.

Other ED Treatments

In some cases, oral pills may be ineffective or unsafe (for example, due to side effects). In such cases, doctors may recommend direct localized prescription treatments, such as:

• Penile Injections (e.g., Alprostadil / Caverject / Tri-Mix): A doctor may inject medication directly into the side of the penis using a tiny needle. It causes an automatic erection within five to 15 minutes, even without arousal.
• Urethral Suppositories (MUSE): This is a tiny medicated pellet that you place inside the urethra (the tip of the penis) using an applicator. The drug dissolves into the surrounding tissue to trigger blood flow.
• Testosterone Replacement Therapy (TRT): When low testosterone is the underlying cause of ED or low libido, a doctor may prescribe TRT via gels, patches, pills, or injections.

Getting Treatment with Curely

Curely is a UK-registered online pharmacy and clinic that supplies medications, including Viagra and sildenafil.

Treatment starts with a short consultation covering your medical history and any medicines you currently take. A qualified clinician reviews your answers to determine whether treatment is appropriate for you.

Once you get a prescription, we deliver the medication to your address discreetly, in unbranded packages. No in-person GP appointments or pharmacy visits; you can do everything from the comfort of your home.

Start your consultation with Curely today to treat erectile dysfunction and other men's health issues.

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FAQs

Is Sildenafil the Same as Viagra?

Yes. Sildenafil is the generic form but contains the same active ingredient as branded Viagra and works in the same way. They're both prescription pills for treating ED in men. The differences between these medications are cost, appearance, and manufacturer.

Why Is Sildenafil Cheaper Than Viagra?

Generic manufacturers of sildenafil didn't fund the original research or clinical trials, so they can produce the pill at a lower cost. Also, when a drug's patent expires, many licensed pharmaceutical companies can sell the same generic medication, causing high supply and thus low wholesale prices.

How Long Does Sildenafil Take to Work?

The active ingredient starts to work within 30 to 60 minutes. However, this varies depending on individual response and whether you eat a heavy or high-fat meal. Speak to your prescriber if you notice no reaction within an hour of taking sildenafil or Viagra with sexual stimulation.

Final Thoughts

Sildenafil and Viagra are the same medicine, and the choice between the two is mostly about price and what's available to you. Note that you should only buy ED medication from registered clinics and pharmacies with a valid prescription, or a health check in the case of Viagra Connect.

Curely offers high-quality Viagra and sildenafil after a thorough clinical assessment, as well as over-the-counter options. We'll send your medication in discreet packaging because we value your privacy. Start your consultation today.

References

1. Ghofrani HA, Osterloh IH, Grimminger F. Sildenafil: from angina to erectile dysfunction to pulmonary hypertension and beyond. Nature Reviews Drug Discovery. 2006;5(8):689-702.
2. Lexchin J. Bigger and Better: How Pfizer Redefined Erectile Dysfunction. PLoS Medicine. 2006;3(4):e132.