Last updated 10 March 2022
To put it simply, tadalafil has a lasting effect for up to 36 hours and occasionally even longer, making it the PDE5 inhibitor with the most extended duration of action available on the market. In comparison, sildenafil (commonly known as Viagra) typically lasts for about 4 hours, which is significantly shorter.
Moreover, the absorption of tadalafil is consistent and not impacted by dietary intake, meaning you can take it at any time, whether before, during, or after meals, without worrying about diminishing its effectiveness.
In medical terms, tadalafil is a medication indicated for the treatment of erectile dysfunction and is categorized as a PDE5 inhibitor. The name tadalafil refers to the generic or non-branded version, while 'Cialis' is its recognized trademark.
36 hours – really?
Absolutely, although it’s crucial to clarify that this does not imply a constant erection for the entire 36-hour window. Like all PDE5 inhibitors, tadalafil needs sexual stimulation to elicit an erection – meaning you will only achieve an erection when you desire it.
The subsequent timeline presents findings compiled from numerous clinical studies. After administering tadalafil:
- First responders: 16 minutes
Some individuals report experiencing an erection as soon as 16 minutes post-administration. - Average responders: 30 minutes
For the majority, the effects of tadalafil are felt within 30 minutes, with approximately 52% of patients successfully engaging in sexual intercourse within this timeframe after taking tadalafil. - Maximum effect: 2 hours
After about 2 hours, the peak concentration of the drug occurs in the bloodstream, indicating its maximum effectiveness. - Half-life: 17.5 hours
Tadalafil has a substantial ‘half-life’ of 17.5 hours, which signifies the duration it takes for half of the drug to exit the bloodstream. This prolonged half-life is precisely what contributes to tadalafil's effectiveness over an extended time frame. - Still effective?: 36–48 hours
Some men find they can achieve satisfactory erections for up to 48 hours following ingestion. This characteristic has led to tadalafil being informally dubbed as ‘the weekend pill’ – take it on a Friday night, and you might enjoy its benefits through to Sunday morning! - All gone: 96 hours
After a full 96 hours, tadalafil has effectively disappeared from the bloodstream, marking the end of its active effects.
Bioavailability of tadalafil
The accompanying graph illustrates the bioavailability of a single dose of tadalafil at 20mg over a 96-hour period. Notably, tadalafil levels remain around 100 µg/l (100 micrograms per litre) even after 36 hours from the dose.
Please do not take 10mg or 20mg of tadalafil more than once a day. The 10mg and 20mg dosages are designed for 'as needed' use preceding anticipated sexual activity, and continuous daily consumption is not advisable.
Continuous daily dosing
An alternative option for tadalafil is its availability in continuous daily dosing, where a lower dose (such as 2.5mg or 5mg) is taken once daily at the same time every day. This method acts as a form of regular medication. Over approximately five days, the low-dose tadalafil accumulates in your system, achieving a “steady-state plasma concentration.”
The daily dosage of either 2.5mg or 5mg is particularly recommended for men who engage in sexual activities more than twice a week, or for those who appreciate the flexibility it affords, as no prior planning is necessary for sexual intercourse.
Interestingly, 5mg can also be effective for occasional use, depending on individual responses.
Key facts
- Prescription only: A comprehensive medical consultation is essential before being prescribed tadalafil. This ensures that checks are made for any contraindications and possible drug interactions.
- Starting dose: It is typically recommended to start with a 10mg dose taken about 30 minutes before sexual activity – adjustments can be made to 20mg or 5mg based on individual results.
- Consider daily low-dosing (2.5mg or 5mg) if sexual activity occurs more than twice a week. It’s important to note that tadalafil is the only PDE5 inhibitor available for daily low-dose use.
- Sexual stimulation is a prerequisite for the drug to provide its effects.
- The medication can be taken with or without food.
- Possible side effects are detailed in the manufacturer’s patient information documentation.
- Tadalafil was first marketed under the brand name Cialis in 2003, brought to market by Lilly, a pharmaceutical company.
- The patent for Cialis expired in the UK and other regions in 2017, which allowed generic pharmaceutical manufacturers to enter the market with their version of tadalafil. This has resulted in a significant reduction in prices over time.
Frequently asked questions
Is tadalafil a safe drug?
A thorough review conducted in 2017, encompassing 16 studies and 5189 participants, directly compared the safety and efficacy of sildenafil and tadalafil. Results indicated that both medications possess a similarly positive safety profile. Both demonstrated equivalent efficacy in addressing erectile dysfunction, and patient satisfaction levels were also comparable. However, psychological outcomes showed a marked improvement with tadalafil, likely due to its prolonged action, which lessened the pressure on patients to engage in sexual activity quickly.
Do men prefer tadalafil?
A study from 2003 established that men expressed a preference for tadalafil over sildenafil. This research involved 215 men experiencing erectile dysfunction, randomly assigned to utilize either sildenafil or tadalafil on an as-needed basis over a 4-week timeframe. Following a 1–2 week washout phase, participants were switched to the alternative medication (a crossover study). Neither the participants nor the research investigators were aware of which drug was being administered, ensuring a double-blind study design. The findings indicated that 66.3% of participants favored tadalafil, in contrast to 33.7% for sildenafil, with these results attaining significant statistical relevance. Both medications were well tolerated, exhibiting similar side effect profiles.
Do female partners prefer tadalafil?
A 2008 investigation revealed that 79% of female partners preferred tadalafil over sildenafil, attributing their preference to the more relaxed approach that tadalafil offered regarding sexual intercourse, owing to its extended duration of effectiveness.
Would men who already regularly use sildenafil switch to tadalafil?
Interestingly, research suggests that this is often the case. In a study from 2003 involving 147 men who were habitual sildenafil users, assessments were conducted using sildenafil over a 6-week initiation phase, followed by a 3-week evaluation period. Participants then underwent the same process using tadalafil. Following this, individuals were allowed to select between sildenafil or tadalafil for the subsequent 6 months. Intriguingly, an impressive 90.5% continued to prefer tadalafil, while only 9.5% opted for sildenafil. This preference was consistent regardless of age, severity of erectile dysfunction, or underlying medical conditions. Both medications demonstrated good tolerability and similar side effect profiles.
Can I obtain tadalafil via an NHS prescription?
The availability of medications for erectile dysfunction on the NHS is limited. Only generic sildenafil is routinely prescribed by general practitioners as a primary treatment for erectile dysfunction. Tadalafil may only be available under specific circumstances, such as in patients with conditions like multiple sclerosis or spinal cord injuries. Prescriptions for tadalafil or other alternatives typically require a private prescription. Engaging with a fully regulated online doctor is a secure and convenient way to access your preferred medication for erectile dysfunction.
- NHS – Tadalafil
- Generic tadalafil FAQS
- Branded Cialis FAQs