Cialis is a medication belonging to the class of PDE5 inhibitors. Like its competitors, it blocks the degradative effect of cGMP-specific phosphodiesterase type 5 (PDE5) enzyme which interferes with the process of natural penile erection occurrence.

This anti-ED drug has one highly unique feature: prolonged duration of action. Well, how long does Cialis keep the male organ hard? What conclusions can be made from this?

How Long Does Cialis Stay in Your Body?

According to the official prescribing information, tadalafil, the key component of Cialis, stays in the body for 1.5 days (36 hours). Moreover, it can provide permanent effect when used on a daily basis. For this purpose, lowered dosages (2.5mg and 5 mg) are envisaged. Higher dosages, namely 10mg and 20mg are mainly used as needed, that is, only on days when a patient is planning to have sexual intercourse(s).

Although the drug can remain active in the body up to 36 hrs, this doesn’t mean a man will have an erection for this period. Cialis only works when a patient is sexually excited.

cialis science

Scientific Research: Some Academic Reveals by Healthcare Professionals

Let’s highlight some of the most important findings related to the duration of effect which were revealed during scientific research of tadalafil:

  • The maximum concentration of the pharmaceutical substance in the blood (Cmax) is observed in 2 hours after administration. Tadalafil pharmacokinetics are not affected by meals. (S Thomas Forgue, Beverley E Patterson, Alun W Bedding; Br J Clin Pharmacol. 2006 Mar.).
  • Although it may take about 2 hrs to achieve peak concentrations, the onset of effect was reported within 15 mins of taking and the efficiency persisted for up to 36 hours. (Samuel L Washington, III and Alan W Shindel; Drug Des Devel Ther. 2010; 4.).
  • The half-life of the remedy’s active agent is 17.5 hours in normal healthy male persons and more than 21 hours in the elderly. (Robert M Coward and Culley C Carson; Ther Clin Risk Manag. 2008 Dec.). From this, we can assume that Cialis may work over 36 hours in old patients, hence, they may require lowered doses.
  • The medicament may sometimes last even longer. This may be associated with the age of a patient (as indicated above). Scientists at University of Rome “Tor Vergata” reported that 5% and 2% of intercourses were recorded up to 48 hours and 60 hours respectively, while in placebo takers the rate of successfulness was 0% (Giovanni Vanni Frajese, Flavio Pozzi et al.; Clin Interv Aging. 2006 Dec.).

Cialis – “the Weekend Pill” (“Le Weekender”)

In 2003, Viagra (which came into the US market in 1998 after getting the Food and Drug Administration’s approval) faced a fierce competition. A new rival, Cialis, burst onto the shelves of American and Canadian pharmacies. Even before that, in 2002, it was granted marketing authorization throughout the European Union.

cialis weekend pill eu

This pharmaceutical product was invented by Eli Lilly and some other drugmaking companies back in 1990s but was tested for a long time, so its appearing was somewhat delayed. But it featured the undisputable advantage related to the time of its action.

In the European Union countries, particularly, in France and Belgium, the new product was rapidly dubbed “le weekender.” The explanation of that sophisticated nickname is simple: a patient can administer the yellow tablet on Friday evening and be able to have spontaneous sex till Sunday morning. Alternatively, he can take the pill on Saturday morning and have sexual intercourse(s) for the most part or even the whole weekends. This was a very attractive feature for ED sufferers. It is worth saying that Viagra and other meds from PDE5i class work about four to six hours. Hence Cialis functions 6 times longer (36÷6=6).

The Bottom Line on Cialis’ Duration of Effect

The prolonged time of work is definitely a good thing. It allows a man to make their relationships more romantic, enhance spontaneity of intimacy, and remove a burden of planning sex in advance from their shoulders. Nevertheless, such a feature is not always good for patients.

Say, a male can take some medications which may dangerously interact with the key agent of Cialis. For instance, these may be erythromycin and other CYP3A4 inhibitors which can make the effect of “the Weekend Pill” somewhat unpredictable. In such cases, it is better to have some interval between eliminations of pharmaceutical substances from the body. When a drug stays too long in the system, it is harder to ensure the needed interval between administrations (of Cialis and erythromycin, a CYP3A4 inhibitor, in this case). This may be especially hard for aged patients. In addition, the medication may negatively interact with grapefruit. For lovers of this red (or pink) hued fruit or grapefruit juice, it may be not suitable to wait for 1.5 days till the elimination of Cialis from the organism.

Summing up, in some occasions patients may prefer other ED medicines, which leave the body faster. These may be Viagra, Levitra, and Avanafil.