Tadalafil Vs Cialis: Are They The Same?

If you're exploring treatment options for erectile dysfunction, you may have heard of two types of medication: Cialis and tadalafil.

But what's the difference between the two? In this article we'll compare their effectiveness, side effects and cost, to help you decide which may be right for you.

Article Summary:

• Cialis is the brand name for a drug containing tadalafil, which is a proven treatment for erectile dysfunction.
• Tadalafil is the active ingredient in Cialis, but since 2017 it's also been available on prescription as a generic (non-branded) medication.
• The main difference between Cialis and tadalafil is cost. Because tadalafil is generic, it's often significantly cheaper than Cialis.

Cialis and tadalafil: a brief history

Cialis was one of the first medicines to be approved for the treatment of erectile dysfunction. It's been used to treat people assigned male at birth (AMAB) around the world for over 20 years. [1]

Eli Lilly was the original manufacturer of Cialis. In 2002, following years of thorough clinical trials, it was approved for the treatment of erectile dysfunction in Europe. A year later, Cialis was also approved by the Food and Drug Administration (FDA) for use in the USA. [2]

Cialis and tadalafil are "bioequivalent". This means that they contain the same active ingredients, work in the same way and meet the same safety and quality standards. And this is because tadalafil isn't just the name of the generic drug: it's also the active ingredient in Cialis.

In 2017, the Eli Lilly patent on Cialis ended. This meant that other manufacturers were now able to begin producing their own, non-branded versions of Cialis: generic tadalafil. Today, both the Eli Lilly product, Cialis, and the generic drug, tadalafil, are available to buy in the UK (subject to eligibility and a valid prescription).

How do Cialis and tadalafil work?

Like Viagra, Cialis (and tadalafil) belong to a class of drugs known as PDE5 inhibitors. These drugs help to relax the blood vessels around your penis, increasing blood flow and helping you have prolonged erections when you're aroused. [3]

However, clinical trials have shown that Cialis (and tadalafil) may have a longer lasting effect than Viagra. [4]

Both Cialis and tadalafil are available as either "daily" or "on-demand" treatments:

• Cialis Daily (and Tadalafil Daily) is taken once a day so the drug is always in your system, to provide continuous support. This may make it easier to have spontaneous sex.
• Cialis 36 Hour (and Tadalafil 36 Hour) is the on-demand option. When taken around 30 minutes before sex, it may remain effective for up to 36 hours. [2] This is why it's often nicknamed "the weekend pill". You won't have a constant erection for that time, but you may be able to achieve one whenever you experience sexual arousal.

Neither drug has an impact on your sex drive, and they only help you get erections in response to sexual stimulation. [5] It's also important to remember that Cialis Daily, Tadalafil Daily, Cialis 36 Hour and Tadalafil 36 Hour only treat erectile dysfunction. They have no effect on premature ejaculation or any other sexual dysfunctions. [6]

What do they look like?

Cialis is an oral, tablet-based medication. It’s available in 2.5 mg, 5 mg, 10 mg and 20 mg doses. Its tablets are yellow, film-coated and almond-shaped.

Generic tadalafil is also an oral, tablet-based medication. Like Cialis, it’s available in 2.5 mg, 5 mg, 10 mg and 20 mg doses. It has a similar appearance to Cialis.

What's the price difference between Cialis and tadalafil?

The biggest difference between Cialis and tadalafil is price. Tadalafil is a generic medication, so its price isn't controlled by a single manufacturer. This means that it's often available at a much lower cost than Cialis.

Cialis, on the other hand, is only produced by Eli Lilly, which controls the price without any competition. Since Cialis is a well-known brand name, the manufacturer is able to charge a premium.

Here's a comparison of their prices:

Effectiveness

Because Cialis and tadalafil contain the same active ingredient, they're equally effective at treating erectile dysfunction.

In clinical trials, tadalafil has been shown to have an 80% success rate in the treatment of erectile dysfunction. [7]

Tadalafil has also been shown to be effective for the treatment of pulmonary arterial hypertension (PAH), a medical condition where blood pressure in the lung's arteries is too high. [8] Just like with erectile dysfunction, it works thanks to its relaxing effect on the blood vessels.

Side effects

Cialis and Tadalafil are medically equivalent, which means they also share the same side effects.

Common side effects (seen in 1 to 10 in every 100 patients) include:

• Headaches
• Back pain
• Muscle aches
• Pain in arms and legs
• Facial flushing
• Nasal congestion
• Indigestion [3] [9]

Uncommon side effects (seen in every 1,000 patients) may include:

• Dizziness
• Stomach ache
• Feeling sick (nausea) and being sick (vomiting)
• Reflux
• Blurred vision
• Eye pain
• Difficulty in breathing
• Presence of blood in urine
• Pounding heartbeat sensation
• A fast heart rate
• High blood pressure
• Low blood pressure
• Nose bleeds
• Ringing in the ears
• Swelling of the hands, feet or ankles
• Feeling tired [3] [9]

Although rare, it's important to be aware of the risks of severe side effects. If you experience any of the following side effects, seek immediate medical help by calling 999:

• Allergic reactions, including rashes, swelling of the face or throat blistering of the skin, mouth, eyes and genitals
• Chest pain
• An erection which lasts more than 4 hours (priapism)
• Sudden loss of vision [3] [9]

For a full list of potential side effects, drug interactions, warnings and precautions, read the patient information leaflet (PIL). This is available online, and will also be provided with your medication.

Who shouldn't take Cialis or tadalafil?

Treatment with Cialis or tadalafil may not be suitable for everyone. For example, if you have low blood pressure or uncontrolled high blood pressure, or if you've recently had a stroke or heart attack. [3] [9]. For a full list of conditions which may interact with Cialis and tadalafil, check your patient information leaflet (PIL). And always remember to share your complete medical history with your medical provider before starting a new treatment.

You should also avoid drinking grapefruit juice while you're taking Cialis or tadalafil, because it can affect the way your body metabolises the medication. This could lead to unsafe levels of tadalafil in your bloodstream and increase your risk of severe side effects, as well as conditions like dangerously low blood pressure (hypotension). [10] [11]

Tadalafil vs Cialis: Which is better?

So, what's the difference between Cialis and tadalafil? The truth is, very little. Both drugs are medically equivalent. They improve blood flow to your penis in the same way, and are equally effective at helping you get harder erections. They also have the same potential side effects.

In fact, the main difference between the two is price. If you'd prefer the more cost-effective option, tadalafil may be better for your needs. However, if you'd prefer to use a brand-name product, consider Cialis. It comes down to personal preference.

The other consideration is a lower dose "on-demand" treatment versus a higher dose "daily" treatment. Again, the choice is yours: it comes down to your medical provider's recommendation, as well as your personal needs and preferences. If you'd prefer to only take medication as and when you need it, Cialis 36 Hour or Tadalafil 36 Hour may be the right treatment for you.

Likewise, if you'd prefer a medication which allows for more spontaneous sex, it's worth asking your medical provider if Cialis Daily or Tadalafil Daily is suitable for you.

Thinking about trying an erectile dysfunction medication?

Erectile dysfunction medicine is subject to approval, and should only be prescribed by a registered healthcare professional.

If you have any questions about erectile dysfunction treatment, our friendly team are here to help.

Find out which treatment may be suitable for you with MedExpress.

References

1. Cialis® (tadalafil) marks 10 years since U.S. approval | Eli Lilly and Company [Internet]. Eli Lilly and Company. 2023. Available from: https://investor.lilly.com/news-releases/news-release-details/cialisr-tadalafil-marks-10-years-us-approval
2. Coward R, Carson C. Tadalafil in the treatment of erectile dysfunction. Therapeutics and Clinical Risk Management. 2008 Dec;Volume 4(6):1315–29.
3. Package leaflet: Information for the user CIALIS ® 5 mg film-coated tablets tadalafil [Internet]. [cited 2026 Jun 3]. Available from: https://www.medicines.org.uk/emc/files/pil.7432.pdf
4. Doggrell SA. Comparison of clinical trials with sildenafil, vardenafil and tadalafil in erectile dysfunction. Expert Opinion on Pharmacotherapy. 2005 Jan;6(1):75–84.
5. Can ED drugs really help your sex life? - Harvard Health [Internet]. Harvard Health. 2019. Available from: https://www.health.harvard.edu/mens-health/can-ed-drugs-really-help-your-sex-life
6. Abou Faddan AH, Gaber HD, Oamonov D. Effect of a tadalafil 5-mg single daily dose on lifelong premature ejaculation: A single-blinded placebo-controlled study. Arab Journal of Urology. 2022 Feb 26;20(2):100–4.
7. Sontag A, Rosen RC, Litman HJ, Ni X, Araujo AB. The role of initial success rates and other factors in determining reliability of outcomes of phosphodiesterase inhibitor therapy for erectile dysfunction: a pooled analysis of 17 placebo-controlled trials of tadalafil for use as needed. The journal of sexual medicine [Internet]. 2013 Feb;10(2):541–50. Available from: https://pubmed.ncbi.nlm.nih.gov/22905853/
8. Schwarz E. The emergence of oral tadalafil as a once-daily treatment for pulmonary arterial hypertension. Vascular Health and Risk Management. 2010 Apr;273.
9. Package leaflet: Information for the user TADALAFIL 2.5 mg FILM-COATED TABLETS [Internet]. [cited 2026 Jun 3]. Available from: https://products.tevauk.com/mediafile/id/53589.pdf
10. Shen X, Chen F, Wang F, Huang P, Luo W. The Effect of Grapefruit Juice on the Pharmacokinetics of Tadalafil in Rats. BioMed Research International. 2020 Jan 25;2020:1–6.
11. Thorpe M. Grapefruit Warning: Can Interact With Common Medications [Internet]. Healthline. Healthline Media; 2017. Available from: https://www.healthline.com/nutrition/grapefruit-and-medications