Last updated 10 March 2022
To keep it straightforward, tadalafil is known to remain effective for up to 36 hours and occasionally even longer, which is notably the longest duration of action among all PDE5 inhibitors available on the market. In comparison, sildenafil, commonly referred to as Viagra, typically lasts for approximately 4 hours. This difference highlights tadalafil's unique ability to provide a more extended window of efficacy.
One of the significant advantages of tadalafil is that its absorption is not influenced by food intake. This means you can take tadalafil at any point relative to meals—before, during, or after—without impacting its effectiveness, which adds to its convenience for users.
Tadalafil is specifically utilized for treating erectile dysfunction (ED) and functions as a PDE5 inhibitor. It is important to note that the name ‘Cialis’ represents a popular branded version of tadalafil, while tadalafil itself is the generic name.
36 hours – really?
Absolutely, although it is critical to understand that this does not imply a continuous erection lasting a full 36 hours. As with all PDE5 inhibitors, tadalafil necessitates sexual arousal for proper function—this means that an erection will only occur when sexual stimulation takes place.
The following timeline compiled from various studies provides insight into the typical response times following the ingestion of tadalafil:
- First responders: 16 minutes
Some men report obtaining an erection as quickly as 16 minutes after taking the medication. - Average responders: 30 minutes
Most men experience the effects of tadalafil after about 30 minutes. Research indicates that 52% of patients are able to achieve successful sexual intercourse within this timeframe. - Maximum effect: 2 hours
The drug reaches its maximum concentration in the bloodstream approximately 2 hours after consumption. - Half-life: 17.5 hours
Tadalafil has a half-life of 17.5 hours, indicating that it takes this amount of time for half of the drug to be eliminated from the bloodstream. This extended half-life is what makes tadalafil effective across such a protracted duration. - Still effective?: 36–48 hours
Some users find they can achieve satisfactory erections even for up to 48 hours following ingestion. This is the reason tadalafil is often referred to as ‘the weekend pill’—one can take it on a Friday evening and still benefit from its effects on Sunday morning! - All gone: 96 hours
After 96 hours, tadalafil has nearly completely cleared from the bloodstream.
Bioavailability of tadalafil
The accompanying graph illustrates data regarding the bioavailability of a single 20mg dose of tadalafil over 96 hours. Notably, tadalafil levels remain around 100 µg/l (100 micrograms per litre) even 36 hours after administration.
It is important to not take 10mg or 20mg of tadalafil more than once in a single day. The dosages of 10mg and 20mg are intended for use 'as needed' in anticipation of sexual activity and are not designed for continuous daily consumption.
Continuous daily dosing
In addition to the as-needed dosing, tadalafil is also offered in low daily doses (2.5mg or 5mg), which can be taken at the same time every day as a form of ongoing treatment. This low-dose option allows for a gradual build-up in the system, eventually reaching a “steady-state plasma concentration” within a five-day period.
The daily regimen of 2.5mg or 5mg is particularly recommended for men who engage in sexual activity more than twice weekly, or for those who prefer the freedom and spontaneity this approach provides, eliminating the need for prior planning for intimacy.
For some men, the 5mg dose can also be effective taken on an 'as needed' basis.
Key facts
- Prescription only: It is necessary to undergo a comprehensive medical consultation before being prescribed tadalafil. Medical professionals will check for any contraindications and possible drug interactions.
- Starting dose: The recommended starting dose is 10mg to be taken 30 minutes prior to sexual intercourse. Adjustments can be made to 20mg or 5mg based on individual results.
- Consider daily low-dosing (2.5mg or 5mg) if you are sexually active more than twice a week. Tadalafil is uniquely the only PDE5 inhibitor that can be administrated as a low daily dose.
- Sexual stimulation is vital for the drug to be effective.
- It can be consumed with or without food.
- Possible side effects are thoroughly enumerated in the manufacturer’s patient information leaflets.
- Tadalafil was initially marketed under the brand name Cialis in 2003 by the pharmaceutical company Lilly.
- The patent for Cialis expired in the UK and other locations in 2017, which allowed generic manufacturers to produce tadalafil, leading to a significant reduction in prices.
Frequently asked questions
Is tadalafil a safe drug?
A review published in 2017 encompassing 16 studies and involving 5,189 patients demonstrated that both sildenafil and tadalafil have comparable excellent safety profiles. The study found that both medications exhibited similar efficacy in addressing erectile dysfunction, with patients displaying equal levels of satisfaction with their respective treatments. Tadalafil may offer advantages in psychological outcomes, likely attributable to its long-acting nature, which reduces the time pressure often experienced with other medications when it comes to engaging in sexual intercourse.
Do men prefer tadalafil?
Research conducted in 2003 indicated that a majority of men preferred tadalafil over sildenafil. In this study, 215 men with erectile dysfunction were randomly assigned to take either sildenafil or tadalafil for a period of four weeks. After an initial washout period of 1-2 weeks, they switched to the other medication in a crossover design. The results revealed that 66.3% favored tadalafil compared to 33.7% for sildenafil, with these findings being statistically significant. Both drugs were well-tolerated by the participants, exhibiting similar side effect profiles.
Do female partners prefer tadalafil?
An investigation from 2008 found that 79% of female partners expressed a preference for tadalafil over sildenafil. This preference was generally due to the more relaxed nature of sexual encounters facilitated by tadalafil's longer duration of action.
Would men who already regularly use sildenafil swap to tadalafil?
Interestingly, research suggests that many men make the switch to tadalafil. A study conducted in 2003 examined 147 men with erectile dysfunction who were frequent users of sildenafil. After assessing their experiences with sildenafil for six weeks and then with tadalafil for another six weeks, the participants were given the choice to continue with either medication for the subsequent six months. An impressive 90.5% decided to continue using tadalafil, with only 9.5% choosing sildenafil. This preference held across various factors including age, severity of erectile dysfunction, and underlying conditions. Both medications were well-tolerated and exhibited similar side effects.
Can I get tadalafil on an NHS prescription?
Access to medications for erectile dysfunction on the NHS is quite limited. Currently, generic sildenafil is the only PDE5 inhibitor that GPs can prescribe on the NHS as a standard treatment for erectile dysfunction. Tadalafil is typically only prescribed for patients with specific medical conditions, such as multiple sclerosis or spinal cord injuries. Generally, prescriptions for tadalafil require a private consultation. Seeking assistance from a fully regulated online doctor presents a safe and efficient option to obtain your preferred medication for erectile dysfunction.
- NHS – Tadalafil
- Generic tadalafil FAQS
- Branded Cialis FAQs