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Cialis vs Viagra

Editorial comparison of Cialis (tadalafil) and Viagra (sildenafil). Same drug class context, trial-anchored data, no marketing claims.

Reviewed by the glpzoom Editorial Team against primary clinical sources — FDA labeling, peer-reviewed trials, and specialty-society guidelines.
Content current as of June 2026; updated when guidance or availability changes.

Side-by-side

DimensionCialisViagra
Generic nametadalafilsildenafil
ManufacturerEli LillyPfizer
FDA approved20031998
MechanismSame mechanism as sildenafil — PDE5 inhibition. Longer half-life (17.5 hours vs 4 hours for sildenafil) means effect lasts longer per dose.Sildenafil blocks the PDE5 enzyme, which breaks down cGMP in penile tissue.
DosingAs-needed: 10-20mg before sexual activity. Daily: 2.5-5mg every day at the same time.25-100mg as needed, 30-60 minutes before sexual activity. Maximum 1 dose per 24 hours.
CostGeneric tadalafil $1-8/tablet. Telehealth $30-100/month depending on dose and as-needed vs daily.Branded Viagra ~$70/tablet.

Full Cialis review →

Long-acting PDE5 inhibitor. 24-36 hour duration. Daily low-dose option for spontaneity.

Full Viagra review →

First PDE5 inhibitor for ED. 30-60 min onset, 4-6 hour duration. Now widely available as generic sildenafil.

Frequently asked

How do Cialis and Viagra compare on cost?+

Cialis: Generic tadalafil $1-8/tablet. Telehealth $30-100/month depending on dose and as-needed vs daily. Viagra: Branded Viagra ~$70/tablet. Generic sildenafil $1-5/tablet at most pharmacies with GoodRx-style coupons. Telehealth platforms charge $30-90/month for a typical monthly supply. Real out-of-pocket depends on insurance formulary tier, manufacturer savings programs, and whether a direct-pay channel is available.

Can I switch from Cialis to Viagra?+

Switching between brand-name treatments in the same drug class is common, but the conversion is not always 1:1. Discuss the switch with your prescriber — they'll usually re-titrate dosing rather than substitute equivalent strengths directly.

Are Cialis and Viagra the same drug?+

No. Cialis (tadalafil) and Viagra (sildenafil) are distinct medications from Eli Lilly and Pfizer respectively. They may share a drug class or mechanism but differ in active ingredient, dosing, and approved use.

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