Cialis Dosage Guide: How To Find The Right Strength For You

Cialis is available as both on-demand and daily dosing, with different strengths designed for different needs. The correct Cialis dosage depends on how you take it, how often you need it, and how your body responds to treatment. 

To get the best results, it’s essential to find the correct Cialis dosage for you. Here’s a guide to Cialis dosing and the best dose for both safety and effectiveness.

How Cialis dosage works: on-demand vs daily use

Cialis is widely used to treat erectile dysfunction (ED) and benign prostatic hyperplasia (BPH), a condition that causes an enlarged prostate [1, 2].

The active ingredient in Cialis is tadalafil. Tadalafil is a type of phosphodiesterase-5 (PDE5) inhibitor that works by blocking the breakdown of cyclic guanosine monophosphate (cGMP), which is a key signalling molecule involved in vascular smooth muscle regulation.

By maintaining higher levels of cGMP, tadalafil helps relax the smooth muscle in the blood vessel walls, particularly in the penis. This improves blood flow during sexual stimulation, allowing men with erectile dysfunction to achieve and maintain a firm erection. 

Sexual stimulation is still required for Cialis to work.

Cialis dosage chart:

Cialis Strength	Typical Use
2.5 mg	Daily use for ED
5 mg	Daily use for ED / BPH
10 mg	Standard on-demand dose
20 mg	Higher-strength on-demand dose

One of the biggest advantages of Cialis compared with other ED medications is its long duration of action, which can last up to 36 hours in some men. This extended window allows for greater spontaneity and reduces the need for precise timing around sexual activity.

On-demand vs daily use of tadalafil for erectile dysfunction

Cialis is unique as an erectile dysfunction medication because it can be used in two different ways [3]:

• On-demand dosing: taken before planned sexual activity
• Daily dosing: taken once every day regardless of sexual timing

Both approaches use tadalafil, but at different strengths and for different lifestyles.

On-demand dosing is taken before anticipated sexual activity. It is usually chosen by men who have sex occasionally or prefer not to take a daily medication. 

Daily dosing, on the other hand, involves taking a low dose every day so that tadalafil remains consistently active in the body. This approach is usually preferred by men who want spontaneous sexual activity without planning ahead.

The best dosage for ED is usually based on how often a person is sexually active, how they respond to treatment, and personal preference regarding convenience and routine.

Cialis should not be taken more than once daily, regardless of strength.

Cialis 10mg: the standard starting dose for most men

Cialis 10mg is typically the standard starting dose for on-demand treatment of erectile dysfunction [1]. It is widely used because it provides a good balance between effectiveness and tolerability for most men.

Doctors often prescribe 10mg as the first dose because it is strong enough to work for many patients while still limiting the risk of side effects. For many patients, 10mg provides sufficient improvement in erection quality and does not require any further adjustment.

Cialis 20mg: when the highest dosage is needed

Cialis 20mg is the highest dosage and is used when 10mg does not produce a strong enough or consistent response [3]. It is generally reserved for men with more severe erectile dysfunction or those who do not respond adequately to the lower starting dose.

While 20mg can increase effectiveness, it also increases the likelihood of side effects such as [4]:

• Headaches
• Muscle aches
• Nasal congestion
• Flushing
• Indigestion

For this reason, clinicians usually only increase the dose after confirming that 10mg has been tried correctly on multiple occasions. The goal with 20mg is not simply to increase strength, but to find the most effective dose that still remains well tolerated.

Cialis Daily: 2.5mg and 5mg for spontaneous use

Cialis Daily is designed for men who want continuous erectile support without needing to plan their medication around sexual activity. Instead of taking a tablet before sex, a low dose is taken every day to maintain steady levels of tadalafil in the bloodstream. Clinical research has confirmed that this allows for greater spontaneity in intimate activity. [3].

Cialis Daily 2.5mg: the starting daily dose

Cialis 2.5mg is often used as an initial low daily dose for men who are new to daily treatment or who are sensitive to medication [3]. This allows the body to gradually adjust to tadalafil while maintaining a low risk of side effects.

Although 2.5mg is a lower strength, it can still be effective because continuous daily use builds up stable drug levels over time. Some men notice a gradual improvement in erectile function after several days or weeks of consistent use.

Cialis Daily 5mg: the standard daily dose

Cialis 5mg is the most commonly prescribed daily dose and is often considered the standard maintenance option for erectile dysfunction [3]. 

At this dose, tadalafil provides consistent support for erectile function and allows for spontaneous sexual activity. Many men find this approach more natural because it removes the need to plan and time medication around intimate activity.

In addition, Cialis 5mg is also widely used in men who experience urinary symptoms related to BPH [2]. Daily 5mg dosing can improve urinary flow and reduce symptoms such as frequent urination or a weak stream in men with an enlarged prostate.

Is Cialis Daily right for you?

Daily Cialis is usually most appropriate for men who have frequent sexual activity, typically two to three times per week or more [3].

Some men also choose daily dosing because it reduces anxiety around performance and creates a more natural sexual experience. Others prefer on-demand use because they have less frequent intimate activity and do not want a daily medication routine.

Who should not take Cialis?

• Nitrate users
• Recent heart attack/stroke
• Severe hypotension
• Previous NAION (non-arteritic anterior ischemic optic neuropathy, a rare cause of sudden vision loss)
• Significant cardiovascular disease

Cialis Together 10mg: the over-the-counter option in the UK

In March 2023, the MHRA reclassified Cialis Together (tadalafil 10 mg) as a pharmacy medicine, making the UK the first country in the world to permit over-the-counter access to tadalafil.

Cialis Together is designed for men with mild to moderate erectile dysfunction who:

• Do not require prescription-strength management
• Are assessed as suitable by a pharmacist
• Prefer a convenient access option without a GP prescription

This option is best for men with mild to moderate erectile dysfunction who are considered suitable after a brief clinical screening. It provides easier access to treatment while still maintaining safety controls and professional oversight.

The pharmacist consultation is brief and typically involves asking you questions about your health history, current medications and blood pressure, in order to confirm your suitability for the treatment.

If 10 mg does not have the desired effect, if you require the 20 mg on-demand dose or the 2.5 mg or 5 mg daily option, or if you have underlying health conditions that require medical supervision, a prescription is the best option. At Apomeds, you can complete a secure online consultation with a licensed prescriber. If suitable, you can then receive prescription-strength tadalafil with discreet delivery.

Tadalafil dosage for enlarged prostate (BPH)

Cialis is also licensed for the treatment of benign prostatic hyperplasia (BPH) [2]. Clinical studies have shown that tadalafil 5 mg can relieve the urinary symptoms of an enlarged prostate, such as frequent urination, urgency and difficulty starting to urinate.

For BPH, the standard treatment dose is usually 5mg once daily. This helps relax smooth muscle in the prostate and bladder, improving urinary flow and reducing discomfort over time.

Tadalafil dosage for pulmonary arterial hypertension (PAH)

Tadalafil may also be prescribed for pulmonary arterial hypertension under specialist supervision [5]. The doses used for PAH differ from those used for erectile dysfunction and should only be managed by a specialist clinician.

Dosage adjustments: when your doctor may change your dose

Cialis dosage is not fixed, and healthcare professionals often adjust treatment based on how well it is working and how well it is tolerated. The aim is always to find the lowest dose that delivers consistent results without unnecessary side effects.

Dose adjustments for kidney or liver problems

Men with kidney or liver impairment may process tadalafil more slowly [6]. This can lead to higher drug levels in the blood, increasing the risk of side effects and a longer duration of action.

In these instances, doctors may recommend starting with a lower Cialis dose or increasing dosing intervals to ensure safe use. Specifically, in mild-to-moderate hepatic impairment the dose should not exceed 10 mg, and tadalafil is not recommended at all in severe hepatic impairment (Child-Pugh C).

In severe renal impairment (creatinine clearance below 30 mL/min), once-daily dosing is not recommended, and on-demand doses must be more conservative and spaced further apart.

Dose adjustments for older men

Older adults may, in some cases, be more sensitive to tadalafil due to natural changes in metabolism and cardiovascular function [6]. As a result, clinicians may start at lower doses and adjust gradually based on response rather than age alone.

Does body weight affect your Cialis dosage?

Cialis is not prescribed using a weight-based dosing system, and there is no recommended dosage calculation based on body mass index [6]. 

Obesity can worsen erectile dysfunction by affecting blood vessels, hormones, and metabolic health. This means some men with higher body weight may need more support, although this is not directly due to weight itself.

What to do if Cialis is not working

If Cialis does not seem to work, the issue may not be related to dosage. 

The most common reasons Cialis does not work include [7]:

• Incorrect timing
• Inappropriate use of medication
• Unrealistic patient expectations
• Severe performance anxiety 
• Difficult relationship dynamics

Unlike other PDE5 inhibitors, Cialis is not affected by heavy, fatty meals [8].

The pharmacokinetics of tadalafil are not significantly affected by moderate alcohol consumption. However, excessive alcohol can impair the natural arousal response, lower blood pressure, and increase the risk of side effects such as dizziness, thereby reducing the likelihood of achieving a satisfactory result, regardless of the dose.

If Cialis is not working after multiple attempts, a healthcare professional may recommend adjusting the dose or switching between daily and on-demand use and if necessary, alternative treatments may be considered.

How to take Cialis correctly for the best results

The correct use of Cialis plays an important role in how well the medication works. When taken properly, tadalafil provides reliable support for erectile function and sexual performance.

Timing and food: what you need to know

One advantage of Cialis is that it is not significantly affected by food [9]. It can be taken with or without meals, which makes it more flexible than some other ED medications. On-demand doses are typically taken 30 to 60 minutes before sexual activity, although effects can last much longer [1].

What to avoid when taking Cialis

Certain substances can interfere with safety and effectiveness and should be avoided when taking Cialis, including:

• Alcohol: Alcohol does not significantly affect tadalafil's pharmacokinetics. However, alcohol does influence effectiveness indirectly by impairing the physiological arousal response, reducing blood pressure, and dulling the neurological signals required for erection [8,10]. 
• Grapefruit juice: Combining Cialis with grapefruit juice may interfere with how the medication is metabolised in some individuals and should be avoided [8].
• Nitrate medications: Nitrates should never be used with tadalafil because the combination can cause a dangerous drop in blood pressure [8]. This includes recreational nitrates known as poppers , which can cause a severe and potentially life-threatening drop in blood pressure when combined with tadalafil, regardless of how they are used.

If you are taking medication for any underlying health conditions, it is recommended to talk to a healthcare professional before using Cialis.

Cialis dosage vs Viagra dosage: how do they compare?

Both Cialis (tadalafil) and Viagra (sildenafil) belong to the same class of medications known as PDE5 inhibitors and are effective treatments for erectile dysfunction. However, they differ in how long they last, how they are taken, and the dosage options available [1].

Feature	Cialis (Tadalafil)	Viagra (Sildenafil)
How long it lasts	Up to 36 hours	Typically 4–6 hours
When it starts working	Usually within 30–60 minutes	Usually within 30–60 minutes
Dosing options	On-demand or daily use	On-demand use only
On-demand dosage range	10mg–20mg	25mg–100mg
Daily dosage option	2.5mg–5mg once daily	Not available
Effect of food	Food has minimal impact on absorption	High-fat meals can delay absorption and reduce effectiveness
Best suited for	Men who want greater spontaneity or frequent intimate activity	Men who prefer taking medication only when needed
Duration of flexibility	Allows a wider window for sexual activity over 24–36 hours	Best suited for planned sexual activity within a few hours of dosing

Both medications have a similar safety profile and commonly cause headaches, flushing, nasal congestion, indigestion, and dizziness.

However, tadalafil is more commonly associated with muscle aches and back pain, a phenomenon thought to relate to its cross-reactivity with PDE11 (an enzyme found in skeletal muscle) rather than simply to its longer duration of action, while sildenafil is more likely to cause temporary visual disturbances due to cross-reactivity with PDE6 in the retina.

The choice between Cialis and Viagra depends on several factors, including how often you have sex, your response to treatment, and personal preference. Men who value spontaneity often prefer Cialis due to its longer duration, while those who only need occasional support may find Viagra a suitable option.

Medications that affect how Cialis works

Several medications can interact with tadalafil and may influence how it works in the body. Some medications that may affect how Cialis works include [12,13,14]:

• Certain antifungal medications (e.g. fluconazole)
• Some antibiotics (e.g. erythromycin)
• HIV medications (e.g. ritonavir)

These interactions may increase tadalafil levels in the bloodstream and raise the risk of side effects such as low blood pressure. With potent CYP3A4 inhibitors such as ketoconazole or ritonavir, on-demand dosing should not exceed 10 mg every 72 hours, and daily dosing should not exceed 2.5 mg. If you are taking medication, consult a healthcare professional to understand if tadalafil is safe to use.

Frequently asked questions about the Cialis dose

Here are the most frequently asked questions about the Cialis tablet and Cialis daily dosage.

Can I take Cialis every day?

Yes, daily dosing is safe for many men when prescribed appropriately. It is typically used at 2.5mg or 5mg depending on individual needs and response.

What happens if I take too much Cialis tadalafil?

Taking too much Cialis can increase side effects such as headaches, flushing, dizziness, and low blood pressure. In rare cases, more serious complications may occur, so it is important not to exceed the prescribed dose.

How long does a dose of Cialis last?

On-demand doses of Cialis can remain effective for up to 36 hours, regardless of whether 10mg or 20mg is taken.

Can I switch between on-demand and daily Cialis?

Yes, but this should always be done under medical supervision to avoid overlapping doses and excessive tadalafil exposure.

Does the dose affect how many side effects I get?

Yes, higher doses are generally associated with a greater likelihood of side effects. This is why doctors aim to identify the lowest effective dose for each individual.

Can I split a Cialis tablet?

No. Cialis tablets should be swallowed whole and not split, crushed, or chewed. The tablets are film-coated, and breaking them can affect how the medication is absorbed, alter the dose you receive, and may make the tablet taste unpleasant. If your current dose feels too strong or is causing side effects, speak to your prescriber about switching to a lower strength rather than attempting to split a tablet.