ED Pills

Tadalafil vs. Sildenafil: Which is Better?

April 26, 2021

Medically reviewed by

Anthony Puopolo, MD

An estimated 30 million men in the United States are routinely affected by erectile dysfunction. When something is this common, there are often tons of potential treatment options. Some of the most popular and effective treatments for erectile dysfunction are prescription medications, including sildenafil, the active ingredient in Viagra®, and tadalafil, the active ingredient in Cialis®.

While they're both highly effective treatments for erectile dysfunction, they have quite a few differences – and each has valid claims regarding superiority.

What Are Tadalafil and Sildenafil?

Both tadalafil (Cialis®) and sildenafil (Viagra®) are oral medications that are used for treating erectile dysfunction. They are in a class of drugs called phosphodiesterase 5 (PDE5) inhibitors that also include vardenafil (Levitra) and avanafil (Stendra).

Erections are caused by the engorgement of the penis with blood. Under regular conditions, sexual stimulation and arousal leads to the production and release of nitric oxide in the penis. Nitric oxide is responsible for the activation of the enzyme guanylate cyclase, which causes the production of cyclic guanosine monophosphate (cGMP).

It is this cGMP that is primarily responsible for the erection as it affects the amount of blood that the blood vessels will deliver and remove from the penis.

PDE5 is an enzyme that breaks down cGMP. Tadalafil and sildenafil inhibit PDE5. By preventing the destruction of the cGMP and allowing it to accumulate and persist for longer in the penis, the penis can remain engorged, firm, and long for longer.

Think of PDE5 inhibitors like the brakes on the car. Removing the brakes allows the car to go faster and further more easily.

Which One Came First, Viagra or Cialis?

Viagra (sildenafil) is a few years older than Cialis (tadalafil) and was the first oral treatment for erectile dysfunction approved by the FDA.

On March 27th, 1998, Viagra (sildenafil) became the first oral pill, and first PDE5 inhibitor, to be approved by the Food and Drug Administration to treat erectile dysfunction in the U.S. Viagra (sildenafil) was developed and sold exclusively by the pharmaceutical company Pfizer for 15 years until their patents expired in 2017 and the first generic versions were introduced.

After this, other companies were legally allowed to produce, market, and sell their own version of sildenafil. The first generic sildenafil was approved in March of 2016 and released on the market in December of 2017.

Cialis was first approved for treating erectile dysfunction on November 21st, 2003 and was the third PDE5 inhibitor to hit the market (after vardenafil [Levitra]).

The pharmaceutical company named Eli Lilly was the developer and patent-holder for tadalafil until November of 2017. After key patents expired, several other companies were permitted to make their own versions of tadalafil and sell these cheaper options on the market.

Which One Lasts Longer?

Cialis (tadalafil) will stay in your body for four to six times longer than Viagra (sildenafil).

Both Viagra (sildenafil) and Cialis (tadalafil) can reach their maximum effectiveness in as little as an hour, but for some patients they may work more quickly.

One of the largest differences between the two medications is how long they stay in your body. Viagra (sildenafil) will stay in your body for six to eight hours but Cialis (tadalafil) can work for an incredible 24 to 36 hours. For this reason, Cialis is often known as "the weekend pill." While this means that the benefits of the drug will last longer, it also means that any side effects can as well.

If you experience any side effects while taking erectile dysfunction medications, it may be a better choice to go for the one with the shorter duration

Is There A Difference In Dosage?

Yes, Viagra (sildenafil) is only taken “as needed” with doses of 25 mg, 50 mg, and 100 mg. Cialis (tadalafil) can be prescribed for daily use with doses of 2.5 mg or 5 mg, but also “as needed” like Viagra at 10 mg or 20 mg.

Since Cialis (tadalafil) will stay in your body longer, it changes the options for the prescription a little when compared to Viagra (sildenafil). For example, Cialis can either be taken as a daily dose or only when needed.

For individuals that are not sure when sexual activity may occur and want to be prepared for all situations, daily usage is probably the best choice. This tadalafil dose is between 2.5 mg and 5 mg and should only be taken once a day. You should not exceed 10 mg in 72 hours. Cialis can be prescribed to be only taken when needed as well. These doses will typically start at 10 mg and increase to 20 mg or decrease to 5 mg depending on results. Viagra, on the other hand, is only available on an “as needed” basis. The dose options are 25 mg, 50 mg, or 100 mg.

Does Food Affect Them?

It’s possible for Viagra (sildenafil) to be negatively impacted by food, while Cialis (tadalafil) is not affected by food at all.

Viagra will generally work within 30 minutes of ingestion, but its effects can be delayed or diminished depending on food. If you are to eat a large, heavy, or high-fat meal, sildenafil's effects could be negatively impacted. It’s recommended to take Viagra on an empty stomach if possible, but having a light meal beforehand shouldn’t cause much harm.

Cialis, on the other hand will typically work within 45 minutes of ingestion, but its activity is not affected by food.

Alcohol can potentially create issues for both options, so it’s best to limit it to one or two drinks at most. Moderate to heavy alcohol consumption while using them could lead to dampening the effects of the medications or blood pressure related health issues.

Which One is Cheaper?

The cost will depend on several factors, but Viagra (sildenafil) is often cheaper.

Depending on where you're looking and what your specific insurance plan covers, the prices you pay may be different than the following costs.

That being said, in most cases the brand name Cialis is not typically covered by Medicare or most insurance plans. Some plans may cover the generic version of tadalafil. The average retail cost of generic tadalafil is roughly $275 for 30 tablets at a 2.5 mg dose.

The brand name of Viagra is also not usually covered by Medicare and most insurance plans. Some insurance plans may offer to cover the generic sildenafil. The average retail cost of generic sildenafil can range from $140 to $400 for 30 tablets of a 25 mg dose.

Rex MD has both medications for even less.

Are There Any Side Effects?

Since Cialis will stay in your system longer than Viagra, it’s important to know what the side effects can be as it may alter your decision. The longer it’s in your system, the longer you may feel the side effects. The most common side effects of Cialis are headache, indigestion, and flushing of the face or body, but even these are fairly uncommon.

Other possible side effects may include:

Headaches
Indigestion
Flushing
Nosebleeds
Trouble sleeping
Fever
An erection lasting longer than normal
Respiratory infection
Nausea
Vomiting
Blurred vision or a blue tint
Bronchitis
Sore throat
Runny nose

Other more serious symptoms are possible and could potentially be life threatening.

While these are rare, it’s important to keep in mind that they are possible:

Low blood pressure, which can cause blurry vision, dizziness, fainting, lightheadedness, nausea or vomiting, sleepiness, and weakness
Increased shortness of breath or issues breathing
Priapism or an erection that lasts more than four hours
Vision problems, such as losing vision in one or both eyes
Hearing problems, such as sudden hearing loss or tinnitus
Heart problems, such as heart attack, stroke, or irregular heart beat

While the side effects listed above do happen, they are fairly rare. However, there are a few other situations that are important to avoid in order to stay as safe as possible while taking either medication.

You should not be taking Viagra or Cialis if you are:

Over 65 years old
Take nitrates or alpha blockers
Take Riociguat for pulmonary arterial hypertension
Are not healthy enough for sexual activity

Do More People Like Tadalafil or Sildenafil?

It can be hard to compare drugs directly, but the research seems to indicate that more men and their partners prefer tadalafil to sildenafil when give the choice. A 2017 meta-analysis of sildenafil and tadalafil research concluded: "Tadalafil shares a similar efficacy and safety with sildenafil and significantly improves patients' sexual confidence. Furthermore, patients and their partners prefer tadalafil to sildenafil. Hence, tadalafil may be a better choice for ED treatment."

There you have it.

The Takeaway:

It can depend on a few factors, but tadalafil is often preferred by both men and their partners, despite Viagra’s long-time popularity.

The benefits of Cialis (tadalafil) make it, objectively, a superior option when compared to Viagra (sildenafil). Although sildenafil has been around longer and is often a cheaper alternative, tadalafil will not only last longer, but has a daily dose option and is not affected by food. This makes it the more versatile option of the two and easier to manage.

While preference often comes down to personal experience, if you're dealing with ED, getting any assistance is the best first step.

Rex MD is here for that, with generic ED meds ordered online and delivered to your door, if approved. It's fast and easy, and it's all at rock-bottom prices.

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