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Tadalafil (generic Cialis®)

Tadalafil (Cialis®) is a prescription medication approved by the Food and Drug Administration (FDA) to treat symptoms of erectile dysfunction (ED), benign prostatic hyperplasia (BPH) and pulmonary arterial hypertension (PAH).

For most men affected by ED and BPH, and for anyone with PAH, tadalafil is a safe and effective treatment option. It’s only available via prescription, so it’s important to talk to your doctor to determine if tadalafil is right for you.

Take tadalafil with a glass of water with or without food either once daily or as needed for ED. If you’re taking it as a daily medication, remember to take it at the same time every day.

The most common recommended dosage of tadalafil for ED is 10 mg (milligrams) as needed.

When prescribed for the treatment of BPH, most doctors recommend 5 mg, and for PAH, the recommended dose is 40 mg (taken as two 20-mg pills).

However, when it comes to dosing and instructions, follow your doctor’s recommendation.

Like all medications, some side effects can occur when taking tadalafil. The most common side effects include:

Additional side effects can be more serious:

  • Dizziness
  • Erections that last longer than four hours
  • Hearing loss
  • Vision problems

If you experience dizziness, an erection that lasts longer than four hours, hearing loss, vision problems, or any other unusual side effects, contact your healthcare provider immediately.

Tadalafil can interact with medications. Talk with your healthcare provider if you’re on any of the following:

  • Alpha blockers: Medications like doxazosin and tamsulosin used to treat hypertension can interact with tadalafil, producing dangerous side effects.
  • Nitrates: Nitrates, nitroglycerin-based medication, and other medications prescribed to treat chest pain and angina (including amyl nitrite) can cause a negative reaction when combined with tadalafil or other PDE5 inhibitors.
  • Riociguat (Adempas®): If you take riociguat for PAH, check with your healthcare provider before taking tadalafil.
  • St. John’s wort: Some herbal and over-the-counter remedies can interact negatively with tadalafil. If you’re taking any herbal products, including St. John’s wort, be sure to tell your healthcare provider.
  • Antibiotics: Some antibiotics, including clarithromycin, erythromycin, and telithromycin, can increase blood levels of tadalafil, causing unwanted side effects. This can include priapism, or prolonged erections. Additionally, rifampin and other types of antibiotics may lower the level of tadalafil in your blood, reducing its efficacy.
  • HIV medication: Certain HIV medications and protease inhibitors can also raise levels of tadalafil in your blood, causing unwanted side effects and in some cases leading to priapism. Consult with your doctor if you’re currently taking ritonavir or lopinavir.
  • Oral antifungals: Some antifungals like ketoconazole and itraconazole may raise tadalafil levels in your blood.
  • Other ED medicationsSildenafil (Viagra®) and vardenafil (Levitra®) should not be combined with tadalafil, as this may increase the risk of side effects.

It should also be noted that tadalafil is not a replacement for safe sex practices, nor can it prevent sexually transmitted diseases.

Talk to a doctor to get your tadalafil prescription today.


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How long does it take for tadalafil to work?

Tadalafil takes about 30 minutes to take effect (but may take up to two hours) and can last in your system for up to 36 hours.

How much does tadalafil cost?

Costs of tadalafil will vary depending on your medical provider and pharmacy. With K Health, you can speak to a doctor and get a tadalafil prescription for as low as $11.

How does tadalafil work?

Tadalafil is a phosphodiesterase-5 (PDE5) inhibitor. In the treatment of ED, tadalafil works by relaxing the penile muscles, expanding blood vessels that go into the penis, and improving penile blood flow during sexual stimulation. This helps get and maintain better erections. In the treatment of BPH, tadalafil helps to relax the bladder and prostate muscles to improve symptoms like painful or frequent urination. And in the treatment of pulmonary arterial hypertension (PAH), tadalafil can help to relax blood vessels in the lungs to allow blood to flow more easily and improve the ability to exercise.

How long does tadalafil last?

Tadalafil can last in your system for up to 36 hours. In the treatment of erectile dysfunction (ED), it can help men get erect at any time during that window.

Can you buy Viagra or Cialis online?

You can buy Viagra® and Cialis® online if you have a prescription from a doctor. With K Health, you can text with a doctor, get a generic Viagra® or Cialis® prescription, and get your medication shipped directly to your home.

Can you buy tadalafil online?

You can buy tadalafil online if you have a prescription from a doctor. With K Health, you can text with a doctor, get a tadalafil prescription, and get your medication shipped directly to your home.

Can you buy sildenafil online?

You can buy sildenafil online if you have a prescription from a doctor. With K Health, you can text with a doctor, get a sildenafil prescription, and get your medication shipped directly to your home.

Can you buy erectile dysfunction medication online?

Yes, you can buy erectile dysfunction medication online, but you will need a prescription from a doctor to facilitate the purchase. With K Health, you can text with a doctor and get your ED prescription delivered straight to your door.