How To Use Cialis
Complete Step-by-Step Usage Guide, Dosage Instructions & Safety Information
Key Takeaways: Using Cialis Safely & Effectively
- On‑demand dosing: Take 10mg or 20mg at least 30 minutes before sexual activity; effects last up to 36 hours.
- Daily dosing: 2.5mg or 5mg once daily, regardless of timing of sexual activity.
- Stimulation required: Cialis only works when you are sexually aroused – it does not cause automatic erections.
- Do not exceed one dose per day: For on‑demand use, maximum one tablet in 24 hours.
- Food: Can be taken with or without food; high‑fat meals do not significantly affect absorption.
- Contraindications: Never take with nitrates or riociguat; avoid if you have severe heart disease, recent stroke, or very low blood pressure.
For a detailed explanation of how Cialis works chemically, see our guide on How Does Cialis Work in the Body.
Important Medical Advice
If you experience an erection lasting more than 4 hours (priapism), sudden vision loss, or chest pain after taking Cialis, seek immediate medical attention. Do not take Cialis with nitrates (e.g., glyceryl trinitrate) as this can cause a dangerous drop in blood pressure.
How to Take Cialis: Step‑by‑Step Usage Guide
Follow these steps to ensure you use Cialis correctly and safely.
- Complete a medical consultation: Before using Cialis, speak with a UK‑registered doctor via an online consultation to confirm it is safe for you.
- Check the dose: Your doctor will prescribe either on‑demand tablets (10mg or 20mg) or daily tablets (2.5mg or 5mg).
- Take the tablet: Swallow whole with a glass of water. Do not crush or chew.
- Timing (on‑demand): Take at least 30 minutes before planned sexual activity. Because it works for up to 36 hours, you don't need to time it precisely.
- Stimulation is essential: Engage in foreplay – Cialis only works when you are sexually aroused.
- Do not overuse: For on‑demand, never take more than one dose in 24 hours. For daily use, take at the same time each day.
🗒️ Practical tip: Many men find it helpful to take Cialis and then engage in normal activities; the medication will be ready when you are.
Cialis Dosage Guide: 10mg, 20mg and Daily Options
Cialis is available in several strengths. Your doctor will recommend the most suitable based on your needs and medical history.
| Dose | Regimen | When to take | Duration of effect |
|---|---|---|---|
| 10 mg | On‑demand (starting dose) | At least 30 min before sex | Up to 36 hours |
| 20 mg | On‑demand (maximum dose) | At least 30 min before sex | Up to 36 hours |
| 2.5 mg | Daily | Once daily, same time each day | Continuous low level |
| 5 mg | Daily | Once daily, same time each day | Continuous therapeutic level |
If you are taking on‑demand Cialis and the 10mg dose is too weak, your doctor may increase it to 20mg. Daily dosing is ideal for men who have sex frequently (e.g., twice a week or more) and prefer spontaneity.
Who Should Use Cialis: Suitable Candidates
Cialis is licensed for adult men (18 years and over) who have erectile dysfunction – difficulty getting or keeping an erection sufficient for sexual activity. It may be appropriate if you:
- Have been diagnosed with ED by a healthcare professional.
- Are in generally good health, with stable cardiovascular status.
- Have not had a heart attack or stroke in the last 6 months (individual assessment required).
- Are not taking nitrates or other contraindicated medicines.
- Are able to engage in sexual activity without undue cardiac risk.
Always consult a doctor to confirm that Cialis is safe for you.
Who Should NOT Use Cialis: Contraindications and Warnings
According to the patient information leaflet and clinical guidelines, do not take Cialis if:
- You take nitrates (e.g., glyceryl trinitrate, isosorbide mononitrate) for angina – this combination can cause a severe drop in blood pressure.
- You take riociguat (for pulmonary hypertension).
- You have severe heart disease or had a heart attack in the last 90 days.
- You have had a stroke in the last 6 months.
- You have very low blood pressure or uncontrolled high blood pressure.
- You have ever had vision loss due to NAION (non‑arteritic anterior ischemic optic neuropathy).
- You are allergic to tadalafil or any tablet ingredients.
🗒️ Note: This list is not exhaustive. Always disclose your full medical history and current medications to your doctor.
Taking Cialis With or Without Food: What You Need to Know
Cialis can be taken with or without food. Unlike sildenafil (Viagra), a high‑fat meal does not significantly reduce its absorption. However, very heavy meals may slightly delay the time it takes to start working.
For fastest onset, some men prefer to take it on an empty stomach, but this is not necessary. The key is consistency – if you usually take it with food, the effect will still be reliable.
Alcohol: Drinking alcohol (especially excessive amounts) can impair your ability to get an erection and may increase the risk of dizziness. Moderate intake (1‑2 units) is generally safe.
Special Conditions: Use in Specific Populations
Cialis is not intended for use by women. Therefore, pregnancy and breastfeeding considerations do not apply. However, there are other special populations:
- Elderly (≥65 years): No dose adjustment is usually needed, but older men may be more sensitive to side effects (e.g., dizziness).
- Kidney problems: If you have severe renal impairment, the maximum recommended dose is 10mg on‑demand (not more than once every 48 hours) or 5mg daily. Mild‑moderate impairment usually requires no adjustment.
- Liver problems: In mild‑moderate hepatic impairment, use with caution; maximum dose 10mg on‑demand. Cialis is not recommended for severe liver impairment.
- Diabetes: Cialis is effective and safe for men with diabetes, but your doctor will check for any underlying cardiovascular risks.
- Children and adolescents: Cialis is not indicated for individuals under 18.
Always inform your doctor about any underlying health conditions.
Cialis Usage FAQs
Can I take Cialis every day?
Yes, a daily dose of 2.5mg or 5mg is available for men who expect to have sex frequently. It provides continuous low‑level medication, allowing spontaneity.
How long before sex should I take Cialis?
Take on‑demand Cialis at least 30 minutes before sexual activity. Because it works for up to 36 hours, you don't need to time it precisely – many men take it and are ready any time during that window.
Can I take Cialis with food?
Yes, Cialis can be taken with or without food. Unlike some other ED medications, a meal does not significantly affect how well it works.
What if I miss a daily dose of Cialis?
If you miss a daily dose, take it as soon as you remember, unless it's almost time for the next dose. Do not double up. Resume your usual schedule the next day.
Can I take Cialis if I have high blood pressure?
Yes, if your blood pressure is well controlled and you are not on nitrates. Some blood pressure medications (alpha‑blockers) may interact, so your doctor will assess suitability.
Ready to Start Treatment with Cialis?
A quick online consultation with a UK‑registered doctor will determine if Cialis is right for you. If approved, your prescription will be dispensed by our GPhC‑registered pharmacy and sent discreetly.
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Medical Content Manager
Nabeel is a co‑founder and medical content manager of Chemist Doctor. He works closely with our medical team to ensure the information is accurate and up‑to‑date.
Medical Doctor
Dr. Feroz is a GMC‑registered doctor and a medical reviewer at Chemist Doctor. He oversees acute condition and urgent care guidance.
Medical Director
Usman is a co‑founder, and medical director of Chemist Doctor. He leads the organisation's strategic vision, bridging clinical and operational priorities.
Review Date: 14 February 2026
Next Review: 14 August 2026
Published on: 14 February 2026
Last Updated: 14 February 2026