How Long Does Tadalafil Stay in Your System? – Proven Facts

Tadalafil is FDA-approved long-acting oral therapy for ED. In comparison to other PDE5 inhibitors, tadalafil has a characteristic longer duration. Despite this, the length of time that tadalafil stay in the system differs from the length of time that tadalafil has the ability to assist in obtaining and maintaining an erection.

For healthy adults, the half-life of tadalafil is approximately 17.5 hours. The effects of tadalafil on forming an erection can last for up to 36 hours.

An understanding of how tadalafil is eliminated, the length of time that tadalafil has the ability to form an erection, and the half-life of tadalafil helps to explain why some tadalafil can remain in the system for more than 36 hours.

How Long Does Tadalafil Stay in Your System?

Tadalafil has an average half-life of 17.5 hours. The half-life of a drug is approximately how long it takes for the concentration of the drug, in this case tadalafil, to be reduced by 50%.

Using the average half-life, most of the drug is cleared over a long period of time:

This is an estimate using the half-life and not a specific length of time for each individual.

How Long Does Tadalafil Last for ED?

Tadalafil does not stay active in the system for the entirety of its 3 to 4 days. The clinically noted period for the erectile function effect of tadalafil after an as-needed dose is 36 hours.

A randomized control study of 348 men with ED measured tadalafil 20 mg against a placebo. At approximately 36 hours after dosing, 59.2% of men on tadalafil were able to have successful intercourse as compared to the 28.3% of men in the placebo group. At around the 24-hour mark, the groups stood at 52.9% and 29.1% respectively.

Another study

which included 483 men with ED, added tadalafil 10 mg and 20 mg at 24 and 36 hours respectively. The group on 20 mg tadalafil noted successful intercourse attempts at 61.9%, while the group on 10 mg noted successful attempts at 56.2% and the placebo at 32.8% at 36 hours.

This arguably classifies tadalafil as the “weekend pill”, though individual cases vary.

Why Does Tadalafil Last So Long?

As noted by many study participants, the time to reach peak concentrations of tadalafil after an oral dose is approximately 2 hours, with some participants reporting peaks as quickly as 30 minutes.

While food doesn’t affect the absorption of tadalafil significantly, tadalafil can be taken with or without food.

During sexual stimulation, tadalafil helps maintain the cyclic GMP levels thereby allowing relaxation of the blood vessels and improving blood flow to the penis.

Tadalafil will not cause an erection on its own, and requires sexual stimulation.

What Clinical Research Says About Tadalafil’s Half-Life

Pharmacokinetic analysis of 237 subjects reported the mean tadalafil half-life as 17.5 hours, ranging from approximately 11.5 to 29.6 hours in the study population. Researchers found no clinically-significant impact of BMI, age or smoking on tadalafil pharmacokinetics in that analysis.

The FDA-approved prescribing information reported 17.5 hours as the mean terminal half-life in healthy subjects. It states that tadalafil is primarily eliminated through the CYP3A4 pathway. Approximately 61 percent of the administered dose is eliminated through feces and 36 percent is eliminated through urine.

Does Tadalafil Stay Longer in Older Adults?

It was documented in prescribing information for tadalafil, that healthy men 65 years and older have a 25% greater exposure to tadalafil than men 19-45 years. It may be attributed to lower oral clearance. In the absence of these documented health conditions and considerations, it was determined that no tadalafil dose adjustment is warranted on the basis of age alone.

Both functional kidney and functional liver may have an impact on the pharmacokinetics of medication.

What About Tadalafil as a Daily Treatment?

Tadalafil is available as daily treatment as well as on an as-needed basis with higher dosing.

According to prescriptions, steady-state concentrations of tadalafil with once daily dosing are achieved after approximately five days of treatment, with exposure of tadalafil being approximately 1.6 times greater when compared with comparative single-dose exposure.

This suggests that daily tadalafil should be evaluated in the same way as infrequently taken tablets. Daily treatment should be done under the direction of a healthcare professional.

Does Tadalafil Remain Effective for 36 Hours?

The term “lasts 36 hours” can be confusing. It should not be interpreted that tadalafil will provide 36 hours of continuous erection. Rather, studies have found that after being administered tadalafil, men were able to maintain the ability to achieve and sustain an erection for up to 36 hours.

An erection that lasts for more than four hours should be considered a medical emergency as it can cause penile tissue damage.

Can Alcohol Affect Tadalafil?

Alcohol does not accelerate the elimination of tadalafil. However, it should be noted that taking tadalafil while consuming alcohol can increase adverse effects associated with tadalafil, such as a headache, dizziness, increased heart rate, and low blood pressure.

Those with pre-existing cardiovascular issues or taking medications that decrease blood pressure should be most careful when consuming alcohol.

Important Interactions of Tadalafil

There are certain medications that can interact with tadalafil. One of the most clinically relevant drug interactions involves the medication nitrates.

Nitrates are commonly prescribed for chest pain. The combination of tadalafil and a nitrate can result in a substantial drop in blood pressure. Tadalafil should be used cautiously with some alpha-blockers, blood pressure medications, and medications that strongly affect CYP3A4.

Always inform your healthcare professional about your prescription medications, over-the-counter products, and supplements when you are taking tadalafil.

How Long Does Tadalafil Stay in Your System After One Dose?

For a healthy adult, tadalafil takes around 17.5 hours to cut its concentration in the system by half. However, it takes about 36 hours for the drug’s effects to wear off completely. The length of time it takes for the drug to leave the body varies, and is dependent on the individual’s age, liver and kidney health, the presence of other medications, and an individual’s metabolism.

Final Thoughts

Tadalafil has an average terminal half-life of about 17.5 hours. Therefore, it will take several days for the drug to fully leave the system . Its effects on erectile function will wear off after about 36 hours, which is much longer than other available medications for erectile dysfunction.

Although studies have found tadalafil to have clinically meaningful effects at the 24 and 36 hour time-points after dosing, individual differences exist, and the drug must still be dosed according to instructions. Men with heart disease, liver and/or kidney problems, and those on nitrates must consult their physicians before using this drug.