How does Cialis work?
Cialis · tadalafil · by Eli Lilly
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.
Same mechanism as sildenafil — PDE5 inhibition. Longer half-life (17.5 hours vs 4 hours for sildenafil) means effect lasts longer per dose.
Where to get Cialis
Hims
from $13/mo- Best for cash-pay
- Best for speed
Hims ED — generic sildenafil from $13/mo
Ro
from $2/mo- Best for clinical oversight
Ro — original online ED brand, sildenafil & tadalafil
More on Cialis
- How much does Cialis cost?
- Cialis side effects
- Cialis dosing and titration schedule
- Who qualifies for Cialis?
- Cialis drug interactions
- Cialis and pregnancy: safety, planning, breastfeeding
- Cialis and alcohol: what to know
- Cialis missed dose: what to do
- Cialis savings: coupons, manufacturer programs, lower-cost options
- ← Full Cialis overview
People also ask
Frequently asked
How does Cialis work in the body?+
Same mechanism as sildenafil — PDE5 inhibition. Longer half-life (17.5 hours vs 4 hours for sildenafil) means effect lasts longer per dose.
How long until Cialis starts working?+
Most patients notice appetite changes within 1-2 weeks. Meaningful weight or clinical change typically follows the full titration period (3-5 months).