The Independent Pharmacy

Comparison Of Sildenafil vs Tadalafil

Andy Boysan
Andy BoysanBPharmDirector & Superintendent Pharmacist

Reviewed on 29 Dec 2023

For many men facing the challenges of erectile dysfunction (ED), exploring the differences between treatment options like Sildenafil vs Tadalafil can be a key step in finding a solution that brings both comfort and confidence.

Sildenafil Tablets (25mg, 50mg & 100mg)
Sildenafil Tablets (25mg, 50mg & 100mg)
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Sildenafil, commonly referred to by the brand name Viagra, offers a rapid onset, which makes it well-suited for spontaneous sexual activity. In contrast, Tadalafil (Cialis) has an extended duration in the body, providing more flexibility for planning sexual encounters. Recognising these distinctions in the timing of action directly guides recommendations when starting ED treatment.

Tadalafil 2.5mg & 5mg Once Daily Tablets
Tadalafil 2.5mg & 5mg Once Daily Tablets
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In this guide, we'll cover all the differences between Sildenafil and Tadalafil so you can make the right choice for you.

Key Findings:

  • Sildenafil (Viagra) acts quicker, with effects in 30-60 minutes, but lasts only 4-6 hours
  • Tadalafil (Cialis) takes between 30 minutes to 2 hours to work but enables erections for up to 36 hours
  • Both medications improve erection hardness and have comparably mild side effect profiles

Sildenafil vs Tadalafil at a Glance

FeatureSildenafil (Viagra)Tadalafil (Cialis)
Onset of Action30-60 minutes30 minutes to
2 hours
Duration of Effect4-6 hoursUp to 36 hours
Dosage Options25-100mg, taken
as needed
10-20mg for
as-needed use;
5mg daily
Flexibility for UseSuited for immediate
Flexible for planned
or spontaneous encounters
Side EffectsHeadaches, flushing,
ndigestion, nasal congestion,
dizziness, back pain,
visual changes
Headaches, flushing,
indigestion, nasal congestion,
dizziness, back pain
Erection HardnessSlightly firmer peak
erections in some cases
Longer-lasting erection
capability over 36-hour
SuitabilityIdeal for shorter-term
treatment and immediate needs
Better for longer-lasting
effectiveness and flexibility

Sildenafil vs Tadalafil: What’s the Difference?

Sildenafil and Tadalafil have emerged among the most effective and commonly prescribed oral medications for effectively treating erectile dysfunction (ED). Both Sildenafil and Tadalafil work by blocking certain chemicals in the body, which helps increase blood flow to the penis, aiding in erections.

However, there are noteworthy differences between these ED treatment options:

  • Sildenafil is sold widely under the brand name Viagra, while Tadalafil goes by the brand name Cialis
  • Time to onset is faster with Sildenafil, producing effects within 30-60 minutes on average
  • Tadalafil elicits a much longer duration of action, lasting up to 36 hours, with effects that can persist from 24-36 hours after a dose
  • Both medications have similar systemic side effects, but Sildenafil is more prone to temporary visual changes like blurred vision or blue-tinted vision

In weighing the choice between using Sildenafil or Tadalafil for ED, men should reflect on lifestyle preferences and the importance of quick onset versus prolonged duration. Discussing these tradeoffs with a healthcare professional can further assist in selecting the optimal treatment regimen.

Sildenafil vs Tadalafil: How Do They Work?

Sildenafil and Tadalafil work by increasing blood flow to the penis. This allows men to get and maintain erections when sexually aroused.

These medications help by relaxing muscles and widening blood vessels in the penis, which allows more blood flow for an erection. They stop certain signals that would normally prevent this increased blood flow.

By preventing the breakdown of certain chemicals, Sildenafil and Tadalafil enhance erections during sexual activity. The drugs do not instantly produce erections on their own without stimulation. Their effects depend on the body's natural sexual response.

In summary, both options improve erections by widening blood vessels for better blood flow. But normal arousal is still needed to trigger their effects. Comparing how these common erectile dysfunction treatments work helps men understand what to expect.

Sildenafil vs Tadalafil: How Much to Take and When

For Sildenafil, first-time users often begin at a 50mg dose taken approximately 1 hour prior to anticipated sexual activity. The dose may be adjusted between 25-100mg as needed to attain satisfactory erections, but no single dose should surpass 100mg due to health risks at higher doses. Moreover, Sildenafil should not be taken more than once daily with at least 24 hours between doses.

In contrast, Tadalafil has a longer-acting duration and can be taken either as needed prior to sex or regularly each day. For as-needed use, an initial dose of 10mg is typical, taken at least 30 minutes before intercourse. This starting dose may be increased to 20mg or adjusted between 10-20mg based on response, with 20mg being the maximum for a single dose.

As with any new medication, following the prescribing doctor’s instructions for ED drugs is imperative. Dosage guidelines should be carefully followed to safely realise optimal effects. Patients should communicate with their healthcare provider if they have additional questions surrounding how to take Sildenafil or Tadalafil properly.

Sildenafil vs Tadalafil: Which One Acts Faster?

Sildenafil typically has an onset of action of 30-60 minutes.

In comparison, Tadalafil can take as little as 30 minutes to work in some men based on various individual factors but may take 2 hours to reach maximum concentrations in the blood. Consequently, the ability to attain erections from a dose of Tadalafil often occurs closer to the 2-hour mark on average. Tadalafil (Cialis) is often called “the weekend pill” due to its longer duration of action.

Overall, Sildenafil has a definitively faster on-set window than Tadalafil. For spontaneity around sexual activity, Sildenafil offers a slightly quicker path to onset after ingestion. However, planned or daily dosing of Tadalafil provides significantly greater flexibility thanks to a much longer duration of action.

Winner: Sildenafil (faster onset)

Sildenafil vs Tadalafil: Which Lasts Longer?

On average, Sildenafil lasts for approximately 4-6 hours before being eliminated from systemic circulation. This means that after ingesting Sildenafil, the effects enabling erections generally persist for 4-6 hours in the body. Consequently, Sildenafil is well suited for shorter-term treatment in preparation for a specific romantic encounter.

In contrast, Tadalafil has a significantly longer duration with a half-life of 17.5 hours on average. Clinically, this translates into up to 36 hours of enabled erections after taking Tadalafil before sexual stimulation is required again to produce effects. Due to exceeding a day in duration, Tadalafil has been bestowed the moniker “the weekend pill.”

Clearly, Tadalafil’s duration outpaces Sildenafil by a wide margin. While Sildenafil lasts for several hours, a single dose of Tadalafil can enable erections for up to a day and a half. This distinction directly impacts suitability for either shorter planned encounters or wider multi-day periods of sexual activity.

Winner: Tadalafil (longer lasting)

Sildenafil vs Tadalafil: Which Leads to Harder Erections?

Evaluating and comparing the hardness and quality of erections achieved is important to men seeking sexual satisfaction from erectile dysfunction (ED) treatment. Sildenafil and Tadalafil take slightly different approaches toward optimising erection potential.

In a study comparing the two, Sildenafil showed a slight advantage in helping a slightly higher number of men achieve their firmest erections. This suggests Viagra may promote firmer peak erections for some patients.

However, Tadalafil generated longer-lasting erection capability that study volunteers qualitatively preferred over shorter periods of maximal hardness. Cialis provided a greater proportion of the 36-hour dosing period with erections of moderate to high hardness.

So, while Sildenafil seemed to assist slightly better erection hardness at peak, Tadalafil delivered persistent erection hardness over a longer duration which men appreciated. There does not appear to be a clear “winner” in achieving patient satisfaction.

As always, individual health factors like adherence to proper administration guidelines can influence relative results. Discuss tradeoffs between hardness versus duration with a healthcare provider when weighing ED medication options.

Winner: Both (similar effectiveness)

Sildenafil vs Tadalafil: Side Effects

Both ED treatments may cause:

  • Headaches
  • Flushing
  • Indigestion
  • Nasal congestion or a runny nose
  • Dizziness
  • Back pain

These adverse effects typically resolve on their own within several hours.

However, Sildenafil is more likely to cause temporary visual changes like blurred vision, increased light sensitivity, or a blue tinge to vision. Around 3% of men report these visual disruptions. In contrast, Tadalafil (Cialis) does not appear to significantly impact vision for most patients.

On rare occasions, more serious side effects may occur, like sudden hearing loss or priapism (a painful, prolonged erection). Such severe reactions are unusual but require immediate medical attention when observed.

While neither drug is free from potential adverse effects, the likelihood of visual changes provides a slight safety advantage towards choosing Tadalafil. However, both medications are generally well tolerated in most men, especially when using the lowest effective dose.

Winner: Tadalafil (milder side effects)

Sildenafil vs Tadalafil: Interactions

When taking any prescription medication, it’s imperative patients understand potential drug interactions. Both Sildenafil and Tadalafil for treating erectile dysfunction (ED) can pose safety risks when combined with certain other drugs.

Importantly, medications called nitrates, which are used for heart disease and controlling blood pressure, can have dangerous interactions with these ED medications. The additive blood pressure lowering effects increase the risk of side effects like fainting, heart attack, or stroke. Those using nitrate medications absolutely should not take PDE5 inhibitors like Sildenafil or Tadalafil.

These ED medications can also interact with other types of drugs, including those for blood pressure, fungal infections, bacterial infections, seizures, and HIV treatment. Always inform healthcare providers of any regular prescriptions or over-the-counter products when discussing or obtaining ED treatment.

To mitigate complications, have a physician review your medical history and medications list when seeking erectile dysfunction drugs. Be sure to immediately report any worrisome symptoms after taking Sildenafil or Tadalafil, particularly cardiovascular effects. Stay vigilant for interactions to safely incorporate ED treatment into your regimen.

Winner: Both (similar safety profiles)

Sildenafil vs Tadalafil: Can They Reverse ED?

A common question among men considering erectile dysfunction (ED) treatment is whether these medications can permanently reverse ED symptoms. Unfortunately, the answer is typically no in most cases. While they don’t “cure” ED, they are effective in treating the symptoms. Sildenafil, Tadalafil, and other ED drugs induce temporary improvements in erectile capacity but do not treat the underlying cause of ED.

For ED caused by issues like reduced blood flow or nerve damage, which often come with age, medications like Sildenafil or Tadalafil can't reverse these underlying problems. However, enhancing sexual function when taking ED meds builds confidence and helps couples restore intimacy, which indirectly aids in recovery.

Some research shows Tadalafil may protect erectile tissue health, which could hypothetically slow declines over time. However concrete evidence firmly establishing disease modification remains lacking thus far. No strong, controlled trial evidence exists showing these drugs definitively turn back time or arrest progression of ED once present.

In general, Sildenafil, Tadalafil and other ED treatments greatly assist erections when actively taking the medications but do not promise any permanent restoration of normal function after stopping. Combining pharmacotherapy with positive lifestyle changes provides the most enduring hope.

Can You Get Sildenafil or Tadalafil on NHS Prescription?

Yes, Sildenafil is commonly included on NHS prescription formularies for treating erectile dysfunction. Tadalafil is available only on prescription.

How to Choose the Right Option for You

Choosing between Sildenafil and Tadalafil for ED treatment is a deeply personal decision, one that balances your individual health needs and lifestyle preferences with care and understanding. Reflecting on lifestyle factors along with input from a healthcare provider allows customising the choice.

Consider when spontaneity around sexual activity is a priority. Sildenafil offers a faster onset, enabling erections from 30 to 60 minutes after taking a dose. This makes timing sexual encounters easier. However, effects last only 4-6 hours in total.

If flexibility for a wider Friday-to-Sunday sexual schedule is desired instead, Tadalafil works for up to 36 hours after one dose. The longer duration covers multi-day periods of intimacy from a single tablet. However, initial onset takes about 2 hours on average.

Discuss tradeoffs like the timing of effectiveness versus total duration with a doctor. Share any medical history factors like cardiovascular problems which may influence suitability. Outline your typical patterns of sexual engagement.

Arriving at an ED treatment plan aligned to individual circumstances and needs requires candid conversations between patients and medical professionals. Consider preferences, reflect on differences between Sildenafil and Tadalafil, and solicit tailored guidance.

Take Charge of Your Sexual Health

If you're feeling overwhelmed by erectile dysfunction, remember you're not alone. We invite you to explore discreet and understanding treatment options with The Independent Pharmacy, where your health and privacy are our top priorities.

We make physician consultations and customised ED treatment convenient through our secure platform. Begin by confidentially completing a short self-assessment to explore suitable medications like Sildenafil or Tadalafil.

Our UK-registered clinical team will promptly provide you with a list of treatments tailored to your needs and preferences. Then, you'll receive prescribed treatments delivered privately to your home.

You can also find more information in our erectile dysfunction guides.

Regain confidence in the bedroom – you have the power to take control of your sex life. Contact The Independent Pharmacy to start your journey to effectively managing ED:

We’re standing by, ready to help you discreetly achieve treatment success. Get in touch with us today.


Why is Tadalafil so cheap?

Tadalafil is now available as a generic medication since the original patent expired. Generic versions can be produced by competitors, increasing supply and lowering prices through market competition. Branded Cialis still maintains higher pricing.

Does Tadalafil keep you hard after coming?

Individual experiences can vary, but Tadalafil is not proven to directly prolong erections after ejaculation. Its long-lasting effects enable achieving erections when sexually stimulated again during the duration of action.

What is the best pill to stay hard longer?

Among oral ED medications, Tadalafil (Cialis) is considered the longest-lasting option. Effects enabling erections can persist for up to 36 hours from a single dose. This led to its “weekend pill” nickname. However, Tadalafil does not work without sexual stimulation.

Does Cialis make you harder than Viagra?

Small differences may exist in hardness or duration of erections when comparing Tadalafil (Cialis) and Sildenafil (Viagra). But few major studies directly measure comparative efficacy. Both produce firm erections in most men, but patient factors can influence individual responses.


Common questions about sildenafil - NHS (

How and when to take sildenafil - NHS (

How and when to take tadalafil - NHS (

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