Cialis (tadalafil) is an oral prescription medication used to treat erectile dysfunction (ED) and benign prostatic hyperplasia (BPH) in adult men. It enhances blood flow to specific tissues by inhibiting the enzyme phosphodiesterase type 5 (PDE5), allowing smooth muscle relaxation and improved circulation, particularly in the penile and lower urinary tract regions.
Tadalafil is also approved under the brand name Adcirca for the treatment of pulmonary arterial hypertension (PAH), though it should not be taken alongside Cialis (tadalafil) for ED or BPH unless directed by a healthcare provider.
Cialis (tadalafil) is notable for its long duration of action—up to 36 hours—and can be used either as-needed or as a once-daily maintenance therapy, depending on the individual's treatment goals and medical profile.
Key Takeaways
Availability: Cialis (tadalafil) is available by prescription through licensed online pharmacies and telehealth providers, including DrugMart, PlanetDrugsDirect, and Amazon Pharmacy. DrugMart offers the lowest price at $510.42 (adjusted price for 30-tablet equivalent). Purchase right through DrugMart right here.
How It Works: Cialis works by inhibiting PDE5, an enzyme that breaks down cyclic guanosine monophosphate (cGMP). By preserving cGMP levels, Cialis promotes prolonged vasodilation and blood flow in response to sexual stimulation or smooth muscle tension relief in the prostate and bladder.
Common Side Effects: Frequently reported side effects include headache, flushing, indigestion, nasal congestion, back pain, and muscle aches. Serious risks may include prolonged erection (priapism), sudden vision or hearing loss, severe hypotension, or cardiac symptoms in individuals with preexisting heart disease. Seek medical attention if you experience chest pain, dizziness, or an erection lasting longer than four hours.
4 Places to Buy Cialis (Tadalafil) Online
Cialis (tadalafil) is a prescription medication used to treat erectile dysfunction (ED) and benign prostatic hyperplasia (BPH). As a PDE5 inhibitor, it improves blood flow and supports erectile function. Known for its long-lasting effects (up to 36 hours), Cialis comes in both daily-use and as-needed formats.
Cialis Pricing Comparison (Adjusted for 30 Tablets)
Provider | Adjusted Price (30 Tablets) | Dosage Format | Prescription Required | Consultation Required | Same-Day Prescription | Link |
DrugMart | $510.42 | 20 mg (as needed) | Yes | No | No | |
PlanetDrugsDirect | $544.68 | 20 mg (as needed) | Yes | No | No | |
Amazon Pharmacy | $1,725.35 | 20 mg (as needed) | Yes | No | No | |
Treated.com | $2,366.21 | 20 mg (as needed) | Yes | No | No |
Prices updated as of April 5, 2025. All prices are normalized to a 30-tablet quantity. Availability, shipping, and prescription policies may vary by provider.
1. DrugMart
DrugMart offers brand-name Cialis at the lowest adjusted price per 30 tablets for 20 mg dosing.
Original Price: $544.46 for 32 tablets
Adjusted Price: $510.42 for 30 tablets
Prescription Required: Yes
2. PlanetDrugsDirect
CIPA-certified pharmacy offering brand-name Cialis with international shipping.
Original Price: $580.99 for 32 tablets
Adjusted Price: $544.68 for 30 tablets
Prescription Required: Yes
3. Amazon Pharmacy
Amazon offers brand-name Cialis in smaller quantities with fast U.S. delivery.
Price: $345.07 for 6 tablets
Adjusted Price: $1,725.35 for 30 tablets
Prescription Required: Yes
4. Treated.com
Treated.com provides daily-use Cialis (20 mg) with convenient online access and flexible ordering.
Original Price: $2,523.95 for 32 tablets
Adjusted Price: $2,366.21 for 30 tablets
Prescription Required: Yes
What is Cialis (Tadalafil)?
Cialis is an oral prescription medication used to treat erectile dysfunction (ED) and the signs and symptoms of benign prostatic hyperplasia (BPH) in adult men. It belongs to a class of drugs known as phosphodiesterase type 5 (PDE5) inhibitors, which enhance blood flow to specific areas of the body, including the penis, by relaxing smooth muscle in the vascular endothelium.
Cialis is also marketed under the brand name Adcirca for the treatment of pulmonary arterial hypertension (PAH). However, the two formulations are not interchangeable unless specifically directed by a healthcare provider.
Unlike some other ED medications, Cialis has a prolonged duration of action—up to 36 hours—and is available in both daily (2.5 mg or 5 mg) and as-needed (10 mg or 20 mg) dosing regimens.
Warnings and Precautions
Do not take Cialis if you:
Use nitrate medications (e.g., nitroglycerin, isosorbide dinitrate) for chest pain or heart disease
Take riociguat (Adempas) for pulmonary hypertension
Are allergic to tadalafil or any components of the tablet
Tell your doctor before using Cialis if you have a history of:
Heart disease, heart attack, or stroke
Arrhythmias or unstable angina
High or low blood pressure
Liver or kidney impairment (including dialysis)
Retinitis pigmentosa or vision loss
Sickle cell anemia, leukemia, or multiple myeloma
Peyronie’s disease or other penile structural abnormalities
Prolonged erections (priapism)
Bleeding disorders or active ulcers
Sexual activity may not be advisable for patients with cardiovascular risk factors. Always consult your provider to determine if Cialis is appropriate for you.
How to Take Cialis (Tadalafil)
Follow your prescription exactly. Do not alter the dose without consulting your doctor.
Cialis can be taken with or without food.
For erectile dysfunction:
As-needed dosing: Take 10 or 20 mg before sexual activity. Do not exceed one dose per 24 hours.
Daily dosing: Take 2.5 or 5 mg at the same time each day, regardless of sexual activity.
For BPH or combined ED/BPH treatment:
Take 5 mg daily at the same time each day.
Do not split or crush tablets. Swallow whole with water.
Dosing Information
As-needed dose (ED): 10 mg to 20 mg prior to sexual activity
Daily dose (ED/BPH): 2.5 mg to 5 mg once daily
Maximum dose: 20 mg per 24 hours for as-needed use
Dosage adjustments may be required for:
Liver or kidney impairment
Concomitant use with CYP3A4 inhibitors (e.g., ketoconazole, ritonavir)
Elderly patients or those with cardiovascular risk
What to Avoid
Alcohol: Can lower blood pressure and increase the risk of dizziness or fainting
Grapefruit juice: May increase tadalafil levels and side effects—avoid during treatment
Nitrates or “poppers”: Combining these with Cialis can cause dangerous drops in blood pressure
Missed Dose or Overdose
Missed Dose (daily users): Take as soon as you remember. If it's near the time for your next dose, skip the missed dose. Do not double up.
Overdose: Call Poison Control at 1-800-222-1222 or seek emergency medical help. Symptoms include:
Severe dizziness or fainting
Prolonged erection
Chest pain
Rapid heartbeat
Side Effects of Cialis (Tadalafil)
Common Side Effects:
Headache
Flushing (warmth, redness)
Back pain or muscle aches
Indigestion, upset stomach
Nasal congestion
Serious Side Effects (Seek medical attention immediately):
Chest pain or discomfort during sex
Erection lasting more than 4 hours (priapism)
Sudden vision or hearing loss
Lightheadedness, especially after standing
Ringing in ears, swelling, or difficulty breathing (allergic reaction)
Report severe reactions to the FDA: 1-800-FDA-1088
Drug Interactions
Tadalafil can interact with numerous medications. Do not take Cialis if you are using:
Nitrates or nitrite-based recreational drugs ("poppers")
Riociguat (for PAH)
Alpha-blockers (e.g., tamsulosin) unless directed by your doctor
Use caution if taking:
CYP3A4 inhibitors (e.g., ketoconazole, erythromycin, ritonavir)
Antihypertensives
Alcohol
Other ED treatments (e.g., sildenafil, vardenafil)
Always tell your provider about all medications and supplements you are taking.
Storage
Store at room temperature (68°F to 77°F or 20°C to 25°C)
Keep in the original container, away from moisture and heat
Keep out of reach of children
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Sources
Eli Lilly and Company. (2007). Cialis (tadalafil) [Package insert]. https://www.accessdata.fda.gov/drugsatfda_docs/label/2007/021368s012lbl.pdf
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