What is the weekend pill?

Wednesday, April 2, 2025

Viagra is a treatment almost everyone has heard of for erectile dysfunction (ED), but there are alternatives like Cialis (tadalafil). This ED treatment is nicknamed the “weekend pill” as it is effective for up to 36 hours (1). If you take it on a Friday night, it may still be working on Sunday morning.

For many men, this longer window offers more spontaneity compared to other ED medications that need to be taken shortly before sex. But how does Cialis work, and is it the right option for you?

What is Cialis?

Cialis is a tablet that men with erectile dysfunction can take to help them get and maintain an erection (2). Like Viagra (sildenafil) and most other ED treatments, it works by temporarily increasing blood flow to the penis when you are aroused (2).

The key difference? While Viagra and alternatives like Spedra (avanafil) and Levira (vardenafil) typically last from four to six hours, tadalafil lasts for up to 36 hours (1). It offers a longer window of opportunity for spontaneous sex rather than needing to plan around a shorter-acting treatment.

However, this doesn’t mean you’ll have an erection for 36 hours straight. Cialis, like all ED medications, only works when you’re sexually stimulated. It simply increases blood flow when you need it, making it easier to achieve and maintain an erection whenever the moment feels right.

Why is Cialis called the weekend pill?

Cialis has earned the nickname “the weekend pill” because of its long-lasting effects. If you take it on a Friday evening, it could still help you achieve an erection by Sunday morning, allowing for more spontaneity and flexibility in your sex life.

For many men, this makes Cialis a more natural and stress-free option compared to shorter-acting ED medications that require more precise timing. Instead of planning sex around taking a pill, the weekend ED pill lets you relax, knowing that you're covered for a much longer period.

Remember, Cialis doesn’t cause constant erections for the entire weekend. You’ll still need to be sexually stimulated for these “weekender” tablets to work.

How does the weekend pill work?

Cialis belongs to a group of drugs called PDE5 inhibitors, these drugs block an enzyme in the body called phosphodiesterase 5 (PDE5) (3-4).

The PDE5 enzyme helps contract the smooth muscle in your blood vessels, making them narrower and restricting blood flow. By blocking this enzyme, Cialis causes the blood vessels in the penis to stay relaxed, allowing for increased blood flow when you’re sexually aroused. This helps to achieve and maintain an erection strong enough for sex (4).

It’s important to note that Cialis won’t cause an erection on its own. You still need to be sexually stimulated for it to take effect. However, its long-lasting action allows for a more natural experience, rather than having to plan around a pill taken shortly before sex.

How does Cialis compare to other ED treatments?

Viagra was the first and only erectile dysfunction pill in the 80s and 90s (5), but today, there are more options available. The main advantage Cialis has is its weekend-long effects, making it ideal if you want greater spontaneity.

But this isn’t the only thing to consider. Other factors may influence which treatment is right for you:

How quickly it works: Cialis takes 30-60 minutes to start working, similar to Viagra (2, 6). If you want something faster, Spedra works in as little as 15 minutes (7), and Eroxon Gel can work within 5 minutes (it’s also a great option if you prefer a topical gel over tablets) (8).
How much it costs: The weekend pill is more expensive than Viagra and other ED pills. Generic tadalafil is cheaper than branded Cialis, just as generic sildenafil is cheaper than Viagra, and is a good alternative if you’re concerned about cost.
How often you need to take it: Cialis offers a daily low-dose option (2.5mg or 5mg), meaning you don’t have to plan ahead at all. Even if this low-dose option isn’t suitable for you, the long-lasting effects of Cialis make it more convenient than on-demand treatments.

In short, the weekend pill can be a great way to treat erectile dysfunction if you’re looking for flexibility in your sex life. If you’re unsure which ED treatment might be the right choice for you, speak to a healthcare professional who can help guide you to the best option.

Are there any side effects?

Like all medicines, Cialis can cause side effects. The most common include headache, indigestion, back pain, and muscle aches. These may affect more than 1 in every 10 people who use the medicine.

Some people may also experience facial flushing, nasal congestion, or dizziness. Serious side effects are rare, but you should always read the patient leaflet and speak to a healthcare professional if you’re unsure.

Where can I buy this weekend pill?

In the UK, you can buy Cialis or generic Tadalafil in different strengths. Some require a prescription and others are available over the counter:

Prescription Cialis comes in 2.5mg, 5mg, 10mg, and 20mg strengths (9). A doctor may prescribe a daily low-dose version (2.5mg or 5mg) for men who want to be ready anytime, or a higher strength (10mg or 20mg) to be taken as needed – not just on the weekends.
Over-the-counter Cialis is only available in a 10mg strength and is sold in the UK as Cialis Together (10). Although you can buy it without a prescription, you’ll still need to complete a short consultation, which is reviewed by a pharmacist to check it’s safe for you.

Whenever you’re looking to get a medical treatment, it’s important to only engage with a trusted pharmacy. This ensures that you get a genuine product and that your details will be stored securely.

Registered online pharmacies like Oxford Online Pharmacy are a great option, as they allow you more privacy for potentially awkward conversations and give you a discreet and convenient way to access ED pills online.

Our online consultation service is reviewed by an independent UK-registered doctor, who will assess your suitability before any treatment is prescribed.

Browse our ED treatments for more information.