

Tadalafil (Cialis) is a prescription tablet used to treat certain conditions related to blood flow and urinary function in adult men. It belongs to a class of drugs called phosphodiesterase type-5 (PDE5) inhibitors, which work by relaxing blood vessels and improving blood flow in specific parts of the body. This medication should be used only under the supervision of a licensed healthcare provider and requires a valid prescription.
| Category | Information |
|---|---|
| Generic Name | Tadalafil |
| Brand Names | Cialis |
| Drug Class | Phosphodiesterase type 5 (PDE5) inhibitor |
| FDA Approval Year | 2003 (Cialis) |
| Indications | • Erectile dysfunction (ED) • Signs and symptoms of BPH (benign prostatic hyperplasia) • ED + BPH combination |
| Dosage Forms & Strengths | Oral tablets: 2.5 mg, 5 mg, 10 mg, 20 mg |
| Contraindications | • Use with nitrates (risk of severe hypotension) • Hypersensitivity to Tadalafil • Concomitant use with guanylate cyclase stimulators (e.g., riociguat) |
| Warnings & Precautions | • Cardiovascular risk with sexual activity • Hypotension when combined with antihypertensives • Vision loss (NAION) • Hearing loss • Priapism (prolonged erection) |
| Common Side Effects | Headache, flushing, nasal congestion, indigestion, back pain, muscle aches |
| Serious Adverse Effects | Sudden vision or hearing loss, priapism, severe hypotension |
| Drug Interactions | • Nitrates (contraindicated) • Alpha‑blockers (risk of hypotension) • CYP3A4 inhibitors (ketoconazole, ritonavir) increase Tadalafil levels |
| Use in Special Populations | • Dose adjustment may be needed in mild/moderate impairment • Not indicated for pediatric use |
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According to the FDA prescribing information, Tadalafil (Cialis) is approved to treat:
Tadalafil works by blocking an enzyme called phosphodiesterase type-5 (PDE5). By inhibiting this enzyme, the medication helps relax smooth muscles and widen certain blood vessels in the body.
When PDE5 is blocked:
These effects help relieve symptoms related to erectile dysfunction and urinary problems caused by an enlarged prostate.
The correct dose of Tadalafil (Cialis) tablets depends on your doctor’s recommendation and on the condition being treated.
Tadalafil may cause side effects in some people. Many Tadalafil side effects are mild & may improve as your body adjusts to the medication. Contact your provider if side effects are persistent, severe, or interfere with daily activities.
| Common Side Effects of Tadalafil | Mild Side Effects of Tadalafil | Rare or Serious Side Effects of Tadalafil |
|---|---|---|
| Headache | Indigestion (upset stomach) | Sudden vision loss (NAION – non‑arteritic anterior ischemic optic neuropathy) |
| Flushing (warmth or redness of face) | Back pain | Sudden hearing loss |
| Nasal congestion (stuffy nose) | Muscle aches | Chest pain (angina, myocardial ischemia risk in susceptible patients) |
| Dizziness | Mild nausea | Shortness of breath (cardiovascular events) |
| Limb pain | Fatigue | Fainting (syncope due to hypotension) |
| Mild stomach discomfort | Priapism (erection lasting longer than 4 hours) |
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The best time to take Tadalafil depends on how it has been prescribed by your doctor and the condition being treated. This medication may be taken either as needed before sexual activity or once daily, depending on the treatment plan.
When used as needed, Tadalafil is usually taken about 30 minutes before sexual activity. The effects of the medication may last up to 36 hours, which is why it is sometimes referred to as the “weekend pill.” It should not be taken more than once per day.
Some patients are prescribed a low daily dose of Tadalafil. In this case, it should be taken at approximately the same time each day, regardless of sexual activity. This approach allows the medication to maintain a consistent level in the body.
Always consult a professional if you are unsure about the correct timing or dosing of this medication.
Do not take Tadalafil if you:
Like all prescription medications, Tadalafil may carry certain risks if not used correctly. Some important safety warnings to consider while taking this medication include:
If you miss a dose of Tadalafil, what you should do depends on how the medication was prescribed.
Do not take two doses at the same time or take extra medication to make up for a missed dose.
Taking too much Tadalafil may increase the risk of serious side effects and require medical attention.
Symptoms may include:
If an overdose of Tadalafil is suspected, seek emergency medical care immediately or contact Poison Control for guidance.
Tadalafil may interact with certain medications that affect blood pressure, metabolism, or blood vessel function. Always inform your provider about all medicines you take.
| Drug Class | Drug Examples | Potential Interaction |
|---|---|---|
| Nitrates | Nitroglycerin, isosorbide dinitrate, isosorbide mononitrate | Combining with Tadalafil may cause a dangerous drop in blood pressure. This combination is contraindicated and must be avoided. |
| Alpha‑blockers | Tamsulosin, doxazosin, terazosin | May cause symptomatic low blood pressure, dizziness, or fainting when used together. |
| Antihypertensive drugs | Amlodipine, lisinopril, losartan | May enhance blood‑pressure‑lowering effects, requiring monitoring. |
| Strong CYP3A4 inhibitors | Ketoconazole, itraconazole, ritonavir, clarithromycin | May increase Tadalafil levels in the blood, raising the risk of side effects. Dose adjustment may be required. |
| CYP3A4 inducers | Rifampin, carbamazepine, phenytoin | May reduce Tadalafil's effectiveness by increasing its metabolism. |
| Other PDE5 inhibitors | Sildenafil, vardenafil | Using multiple erectile dysfunction medicines together may raise the risk of adverse effects. |
| Alcohol | Beer, wine, liquor | Excess alcohol may increase dizziness, headache, and low blood pressure when combined with Tadalafil. |
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If Tadalafil (Cialis) is not suitable or effective for you, your doctor may recommend other medications:
The information provided on this page about Tadalafil (Cialis) is intended for educational and informational purposes only. It should not be used as a substitute for diagnosis, professional medical advice, or treatment. Always consult a qualified provider before starting, stopping, or changing the dosage of any prescription medication. A licensed medical professional can determine whether Tadalafil is appropriate for your medical condition and overall health.
Many U.S. patients find that prescription medications such as Tadalafil can be significantly more expensive at local pharmacies. Ordering from licensed Canadian pharmacy partners through Polar Bear Meds may help eligible patients access the same medication at a more affordable price while maintaining pharmacy safety and regulatory standards.
Polar Bear Meds requires a valid prescription for all Tadalafil orders, helping support responsible and safe medication use.
The cost of Tadalafil may vary depending on the tablet strength, quantity ordered, and current availability. Patients ordering through Polar Bear Meds may also be able to save even more with:

Dr. Jackson Miller is a board-certified medicine physician & hospitalist. He is a healthcare professional with a strong background in patient care. With years of experience and a patient-first approach, he believes the foundation of good health is a patient who feels informed and empowered. He contributes to medical content review, drawing on his background in clinical practice and patient education. He focuses on presenting health information in a clear, accurate, and accessible way to help readers make informed decisions. His work emphasizes clarity, evidence-based guidance, and understandable explanations of medical topics.
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