Tadalafil (Cialis®)

Author: Christina Bach, MBE, LCSW, OSW-C
Content Contributor: Marisa Healy, BSN, RN
Last Reviewed: December 2, 2025

Pronounce: ta-DAL-a-fil

Classification: Phosphodiesterase Inhibitor

About Tadalafil (Cialis®)

Tadalafil is a medication that is taken before sexual activity and helps males with erectile dysfunction (ED) achieve and maintain an erection. Tadalafil is also used to treat benign prostatic hyperplasia (an enlarged prostate gland). ED or impotence happens when males cannot achieve or maintain an erection long enough for sexual intercourse. This can be caused by medical conditions such as high blood pressure, diabetes, prostate problems, or heart disease. It can also be a side effect of the medications often taken for these conditions. Personal lifestyle factors such as stress, alcohol, and/or tobacco use can also play a role. 

During surgery or radiation to the pelvic area (including prostate, bladder, and rectal procedures), damage can occur to the nerves that supply the penis. This can cause temporary or permanent impotence. Some surgeons do "nerve-sparing" surgeries to try to preserve erectile function. Even in these cases, the nerves will suffer some injury, and it can take 18 to 24 months or longer for erectile function to return. These men should be treated aggressively with oral or injectable medications for ED to speed the recovery of the nerves and prevent muscle wasting in the penis.

How to Take Tadalafil

  • Tadalafil is taken by mouth as needed once a day. When used for ED, take at least 30 to 60 minutes before sexual activity. The medication works for up to 36 hours. It can be taken with or without food.
  • Your provider will find the dose that is best for you. Some males will be prescribed a lower dose to take every day. You should not change your dose without talking to your provider first.
  • Males who take tadalafil will not have an erection without sexual stimulation. This drug is not an aphrodisiac and does not affect libido or desire. Having multiple intercourse sessions with one dose has not been studied.
  • Do not drink excess alcohol while taking tadalafil (for example, more than 5 glasses of wine or 5 alcoholic drinks).
  • Males who take nitrates, such as nitroglycerin, Nitro-Bid, Isordil, or Deponit should not take tadalafil.
  • Males who take Cardura, Flomax, or Hytrin for urinary symptoms should not take tadalafil.
  • This medication can affect how other medications work. Be sure your provider and pharmacist know all the medications (prescription and over-the-counter) and supplements you take.

Storage and Handling

Store your medication in the original, labeled container at room temperature and in a dry location (unless otherwise directed by your provider or pharmacist). This medication should not be stored in a pillbox. Keep containers out of reach of children and pets. Ask your provider where to return any unused medication for disposal. Do not flush it down the toilet or throw it in the trash.

Where do I get this medication?

Tadalafil is available through most retail pharmacies.

Insurance Information

This medication may be covered under your prescription drug plan. Patient assistance may be available to qualifying individuals without prescription drug coverage through the pharmaceutical company that makes the medication. Your provider can help you find these resources if they are available.

Possible Side Effects of Tadalafil

There are a few side effects that you may have with tadalafil. Talk to your provider if you have concerns about these side effects. Do not take a higher dose of tadalafil than your provider orders for you.

  • Headache, facial flushing, stuffy or runny nose, and upset stomach can occur.
  • Some patients have back pain or muscle aches that often occur 12 to 24 hours after taking tadalafil. This often resolves on its own, after 48 hours. If you have pain that does not get better or go away, call your provider.
  • Less frequent side effects include blurry vision, a bluish hue to the field of vision, difficulty telling the difference between the colors blue and green, sensitivity to light, or a sudden loss of vision or hearing.

If you experience any of the following while using tadalafil, go to the nearest emergency room or call 911:

  • An erection lasting more than 4 hours.
  • Chest, arm, or neck pain, or nausea during sexual activity.
  • Sudden loss of vision or hearing.
  • You develop an allergic reaction (rash, hives, swelling of the lips, tongue, or throat, difficulty breathing).

Reproductive Concerns

Remember, tadalafil does not protect against sexually transmitted diseases (STDs) or prevent pregnancy. Effective birth control is recommended during cancer treatment. Even if you are not producing sperm, you could still be fertile and conceive.