Viagra vs. Cialis: What's the Difference?

Summary

Viagra and Cialis are prescription medications that work by increasing blood flow in response to sexual stimulation. Both belong to a class of medications called PDE5 inhibitors, but they contain different active ingredients and differ in how long their effects may last. Understanding these differences, along with potential side effects and safety considerations, can help you have a more informed conversation with a healthcare practitioner.

Viagra and Cialis are two well-known medications, but they aren't interchangeable in every situation. 

Each has its own characteristics, and what works for one person may not be the right fit for another. Understanding how these medications differ can help you have a more informed conversation with your healthcare practitioner about your options.

What is the difference between Viagra and Cialis?

Viagra contains sildenafil, while Cialis contains tadalafil. Both medications belong to the PDE5 inhibitor class, which helps increase blood flow during sexual stimulation.

The main differences relate to duration, timing, dosing options, and how each medication may fit into an individual's treatment plan.

For Canadian product information, see Health Canada's Viagra listing and Cialis listing.

How does Viagra work?

Viagra contains sildenafil, which blocks the PDE5 enzyme. This helps maintain the chemical signals that relax smooth muscle and increase blood flow to the penis during sexual stimulation.

Sildenafil does not automatically cause an erection. Sexual stimulation is still necessary for the medication to work.

It commonly begins working within 30 to 60 minutes, although food, individual response, and other factors can affect the timing.

A high-fat meal may delay its effects, so follow the instructions provided with your medication and by your prescribing practitioner.

How does Cialis work?

Cialis contains tadalafil, which also inhibits the PDE5 enzyme. Like sildenafil, it helps increase blood flow during sexual stimulation.

The key difference is how long tadalafil remains effective. Its effects may last up to 36 hours, giving it a longer window of action than sildenafil.

This does not mean an erection lasts for 36 hours or that the medication works continuously without sexual stimulation. Rather, the medication may support the body's response to sexual stimulation during that period.

Tadalafil is also available in dosing regimens intended for daily use when prescribed. Daily dosing is different from taking medication as needed and should only be followed according to a practitioner's instructions.

Cialis vs. Viagra: Which lasts longer?

Cialis generally lasts longer than Viagra.

• Viagra: Its effects commonly last around four hours, although the duration varies.
• Cialis: Its effects may last up to 36 hours.

This difference can influence how each medication fits into a person's routine. However, a longer duration does not automatically mean one medication is more effective or more appropriate for everyone.

The right option depends on individual health factors, other medications, preferences, and the prescribing practitioner's assessment.

Remember that an erection lasting four hours or longer requires immediate medical attention, regardless of which medication was taken.

How quickly do Viagra and Cialis work?

Both medications can begin working within approximately 30 to 60 minutes, but their onset is not identical for everyone.

With Viagra, a high-fat meal may delay how quickly the medication takes effect. Tadalafil's absorption is generally less affected by food.

Neither medication works instantly in every situation. The response may depend on the dose, individual factors, and whether sexual stimulation occurs.

Do not take an extra dose because the medication seems slow to work. Follow the prescribed instructions and ask a pharmacist or prescribing practitioner if you have questions about timing.

What are the side effects of Viagra vs. Cialis?

Because Viagra and Cialis belong to the same medication class, they share several potential side effects. However, some effects are more commonly associated with one medication than the other.

Common side effects of Viagra

Sildenafil may cause:

• Headache
• Facial flushing
• Indigestion
• Nasal congestion
• Dizziness
• Temporary visual changes, including changes in colour perception

Common side effects of Cialis

Tadalafil may cause:

• Headache
• Indigestion
• Back pain
• Muscle aches
• Nasal congestion
• Flushing

Back pain and muscle aches are particularly associated with tadalafil. These symptoms often resolve, but persistent or severe symptoms should be discussed with a healthcare practitioner.

The side effects listed here are not exhaustive. The likelihood and severity of side effects can vary between individuals and may depend on the dose and other health factors.

Are the side effects of Viagra worse than Cialis?

Not necessarily. Neither medication is universally associated with worse side effects.

Some people may experience side effects with one medication but not the other. Existing health conditions, other medications, and individual responses can influence tolerability.

A healthcare practitioner can review these factors when assessing which option may be appropriate.

When should you seek medical attention?

Both medications can cause rare but serious adverse effects.

Seek immediate medical attention if you experience chest pain, sudden loss of vision or hearing, a severe allergic reaction, or an erection lasting four hours or longer.

If you experience chest pain after taking either medication, seek emergency help and tell the medical team what you took and when. Do not take nitrates for chest pain unless emergency clinicians specifically direct your care.

Can you take Viagra and Cialis together?

You should not combine Viagra and Cialis unless a qualified healthcare practitioner has specifically directed your treatment.

Both medications affect the same enzyme pathway. Taking them together can increase the risk of side effects, including dangerously low blood pressure.

The same caution applies to combining either medication with other PDE5 inhibitors. Tell your prescribing practitioner about all medications and supplements you use before starting treatment.

Are Viagra and Cialis safe for everyone?

Neither medication is suitable for everyone. A healthcare practitioner should review your medical history, current medications, and relevant health conditions before prescribing either option.

One particularly important consideration is the use of nitrate medications, which may be prescribed for chest pain. Combining nitrates with sildenafil or tadalafil can cause a dangerous drop in blood pressure.

Other factors that may require assessment include:

• Heart conditions and blood pressure concerns
• Kidney or liver conditions
• Certain eye conditions or previous vision problems
• Other medications that may interact with PDE5 inhibitors
• Previous adverse reactions to similar medications

This list is not exhaustive. Never assume a medication is safe for you based solely on its availability or on someone else's experience.

What about generic Viagra and Cialis?

Generic versions of sildenafil and tadalafil are available in Canada. These contain the same active ingredients as their corresponding brand-name medications and must meet applicable regulatory requirements.

When comparing products, check the active ingredient, strength, product information, and regulatory status. Generic products may differ in appearance, packaging, and non-medicinal ingredients.

A pharmacist can help answer questions about a specific product or a potential switch between brands and generics. Any change should be consistent with your prescription and professional guidance.

Exploring medication options through Pocketpills

If you want to learn more about available medication options, Pocketpills offers online medication information and virtual care for eligible Canadians.

You can visit the Viagra and Cialis’ medication page to review available strengths, dosage information, side effects, and precautions.

If you're exploring whether a prescription may be appropriate, you can also begin an online assessment. A licensed Canadian practitioner can review the information you provide and determine the appropriate next steps. Prescribing depends on clinical assessment and eligibility, and an in-person appointment may be recommended when necessary.

Frequently asked questions

Is Cialis better than Viagra?

Neither medication is universally better. Cialis lasts longer, while Viagra has a shorter typical duration of action. The most appropriate option depends on individual health factors, medication interactions, and the prescribing practitioner's assessment.

Does Cialis last longer than Viagra?

Yes. Cialis may remain effective for up to 36 hours, while Viagra commonly has an effect for around four hours. These timeframes vary, and neither medication causes a continuous erection throughout its duration of action.

Can you switch between Viagra and Cialis?

A switch may be possible, but it should be discussed with a healthcare practitioner. They can review your response, medical history, other medications, and the appropriate timing of any change. Do not take the medications together unless specifically directed.

Do Viagra and Cialis have the same side effects?

They share several possible side effects, including headache, indigestion, flushing, and nasal congestion. Visual changes are associated with sildenafil, while back pain and muscle aches are more characteristic of tadalafil. Either medication can also cause serious adverse effects.

Can you take Viagra or Cialis with alcohol?

Alcohol can contribute to dizziness and lower blood pressure, and heavy drinking may affect sexual performance. Ask a healthcare practitioner about alcohol use in the context of your medication, health conditions, and other medicines.

Are generic versions available in Canada?

Yes. Generic sildenafil and tadalafil products are available in Canada. Confirm the product's active ingredient and regulatory status, and ask a pharmacist if you have questions about a specific generic product.