Quick Facts

Active ingredient: Tadalafil
Primary condition: Erectile dysfunction (ED)
Other related uses: symptoms of benign prostatic hyperplasia (BPH), and pulmonary arterial hypertension (PAH) when prescribed specifically for that purpose.
Claimed available strength: 800 mg tablets (as marketed online). Note: in routine clinical practice in the USA, tadalafil products are typically 2.5 mg, 5 mg, 10 mg, or 20 mg; higher-strength variants such as "Cialis Black 800 mg" are not standard FDA-approved strengths.

Tadalafil helps relax vascular smooth muscle and improves blood flow to certain tissues. For ED, it may enhance erectile response to sexual stimulation. For what this medicine treats, see What It Is Used For.

What It Is Used For

Clinicians may prescribe tadalafil-containing products for:

  • Improving erectile function in adult men with ED.
  • Relieving urinary symptoms of BPH such as weak stream or frequent urination.
  • Treating PAH under specialist care (often as branded or generic tadalafil specifically labeled for PAH).

Always use tadalafil only as directed by your prescriber. For specific instructions on timing and frequency, jump to How to Take It.

How to Take It

Follow the prescription label and your clinician's guidance. General points:

  • Swallow tablets whole with water; do not crush or split unless your pharmacist confirms it is safe.
  • May be taken with or without food.
  • For on-demand ED use, it is usually taken prior to sexual activity and not more than once per day.
  • Some patients use a once-daily lower-dose regimen for ED or BPH; your provider will decide which approach fits you.

Do not change the dose or frequency without medical advice. If you have questions about timing relative to sexual activity, see your clinician and review Before You Start.

Before You Start

To help your prescriber determine if tadalafil is appropriate, disclose your history, especially if you have or had:

  • Heart disease, recent heart attack or stroke, or chest pain/angina.
  • High or low blood pressure, or pulmonary hypertension not being treated with tadalafil.
  • Pulmonary veno-occlusive disease.
  • Liver or kidney problems, including if on dialysis.
  • Vision or retinal disorders (for example, retinitis pigmentosa) or unexplained vision loss.
  • Bleeding disorders or blood dyscrasias (sickle cell anemia, multiple myeloma, leukemia).
  • Peyronie's disease or anatomical penile deformities, or a history of priapism (erection > 4 hours).
  • Active stomach ulcers or any condition making sexual activity unsafe.

If any severe symptoms occur while using tadalafil, stop and seek care immediately. For situations where use is not appropriate, see Do Not Use If.

Do Not Use If

  • You are allergic to tadalafil or any component of the product.
  • You take nitrates (for chest pain or heart disease) including nitroglycerin, isosorbide dinitrate, or isosorbide mononitrate, or recreational amyl nitrite/nitrite "poppers".
  • You use riociguat (a soluble guanylate cyclase stimulator) for PAH.

Combining tadalafil with the medicines above can cause a dangerous drop in blood pressure. For other interacting medicines, see Drug Interactions.

Possible Side Effects

Not everyone experiences side effects, but reported reactions include:

  • Flushing or a sensation of warmth.
  • Headache.
  • Nasal stuffiness.
  • Upset stomach or nausea.
  • Back pain, muscle aches, or limb pain.

Rare but serious events (seek urgent help): chest pain, sudden vision or hearing loss, fainting, or an erection lasting longer than 4 hours.

Drug Interactions

Provide your prescriber with a complete list of medicines, supplements, and recreational substances. Use extra caution with:

  • Other ED medications or agents for PAH.
  • Alpha-blockers and other blood pressure medicines.
  • Antibiotics or antifungals that affect CYP3A4 (for example, clarithromycin, erythromycin, ketoconazole, itraconazole).
  • HIV or hepatitis C antivirals that affect CYP3A4.
  • Seizure medicines such as carbamazepine, phenytoin, or phenobarbital.

Strong CYP3A4 inhibitors or inducers can change tadalafil levels. For absolute contraindications, review Do Not Use If.

Missed Dose

For on-demand ED use, there is usually no dosing schedule. If using a daily regimen and you miss a dose, take it when you remember unless it is near the time for the next dose. Do not double up.

Overdose

If you think you have taken too much tadalafil, call emergency services or go to the nearest emergency department immediately.

Storage and Handling

  • Store at room temperature, away from excess heat and moisture.
  • Keep out of reach of children and pets.
  • Do not use past the expiration date. Ask your pharmacist how to dispose of unused tablets safely.

Similar or Alternative Medicines

If tadalafil is not suitable or not effective, clinicians may consider other PDE5 inhibitors or related approaches. Discussion points for your prescriber:

  • Sildenafil (Viagra, generics): shorter duration than tadalafil; common on-demand option.
  • Vardenafil (Levitra, Staxyn): similar onset to sildenafil; available as tablet or ODT.
  • Avanafil (Stendra): rapid onset for some users; pricier brand in the USA.
  • Tadalafil generics or brand Cialis at standard strengths (2.5 mg, 5 mg, 10 mg, 20 mg), including once-daily 2.5-5 mg for ED/BPH.
  • Non-oral options (by specialist): vacuum erection devices, intracavernosal injections, or urethral suppositories.

Note: Products marketed online as "Cialis Black 800 mg" are not standard FDA-approved strengths. When considering alternatives, confirm FDA approval status and purchase from licensed U.S. pharmacies. For legal considerations, see USA Legal Status.

Approximate Prices in USD

The following are rough U.S. cash price ranges per tablet or dose; actual prices vary by pharmacy, discount programs, strength, and quantity. These figures are not offers:

  • Generic tadalafil 20 mg: about $1 to $6 per tablet.
  • Brand Cialis 20 mg: often $60 to $80 per tablet without insurance.
  • Tadalafil 5 mg (daily): roughly $0.20 to $2 per tablet when purchased in quantity.
  • Sildenafil 50-100 mg (generic): about $0.20 to $5 per tablet.
  • Vardenafil 10-20 mg (generic/brand): about $1 to $7 generic; brand typically higher.
  • Avanafil 50-200 mg (brand Stendra): approximately $5 to $20 per tablet, sometimes more.
  • "Cialis Black" as sold by online vendors: pricing is highly variable due to nonstandard strength/branding; reports range roughly $3 to $15 per tablet, but quality and legality may be uncertain.

Ask your pharmacist about discount cards, manufacturer coupons (for brands), and 90-day fills. Telehealth services may also offer competitive pricing for generics.