Cialis 20 mg by Eli Lilly is the original pharmaceutical-grade oral tadalafil formulation at its maximum approved on-demand dose, supplied as film-coated tablets in boxes of 4 at 20 mg per tablet. As the originator brand under which tadalafil was first developed, clinically investigated, and approved for erectile dysfunction and benign prostatic hyperplasia pharmacotherapy, Eli Lilly's Cialis represents the most extensively documented tadalafil formulation in comparative PDE5 inhibitor clinical literature, distinguished within its drug class by its notably extended plasma half-life of approximately 17.5 hours — the longest documented among approved PDE5 inhibitor compounds.
 
✔ Key Research Insights
Studied for its role in inhibiting phosphodiesterase type 5 enzyme activity in penile corpus cavernosum smooth muscle, with documented enhancement of cGMP-mediated vasodilation and associated improvement in erectile function parameters in research subjects with erectile dysfunction across multiple large-scale randomized clinical trials
Investigated for its extended plasma half-life of approximately 17.5 hours — documented as the longest among approved PDE5 inhibitor agents in comparative pharmacokinetic research — associated with a prolonged therapeutic window of up to 36 hours referenced in international urology clinical literature
Researched for its clinical efficacy in erectile dysfunction across extensively documented subject populations, with established superiority over placebo consistently referenced in international urology clinical guidelines under both on-demand and once-daily dosing protocols
Examined for its effects on lower urinary tract symptoms associated with benign prostatic hyperplasia, with documented smooth muscle relaxation in the prostate, bladder neck, and urethra via PDE5 inhibition referenced in urological research literature — representing a dual clinical indication distinct among PDE5 inhibitor compounds in comparative pharmacology research
Documented for its comparatively reduced food and alcohol interaction profile relative to sildenafil in pharmacokinetic research, with tadalafil absorption documented as minimally affected by concurrent food consumption in clinical observations
Referenced across international clinical guidelines as a first-line pharmacological intervention for both erectile dysfunction management and BPH-associated lower urinary tract symptom relief
 
📦 Product Specifications
Manufacturer: Eli Lilly
Product: Cialis
Molecule: Tadalafil
Drug Class: Phosphodiesterase Type 5 (PDE5) Inhibitor
Concentration: 20 mg per tablet
Form: Film-coated oral tablet
Volume: 4 tablets per box
Dosage considerations may vary. Consulting a qualified professional is recommended.
 
⚙ How It Works
Tadalafil is a selective inhibitor of the phosphodiesterase type 5 (PDE5) enzyme, the primary enzyme responsible for degradation of cyclic guanosine monophosphate (cGMP) in smooth muscle tissue of the corpus cavernosum, prostatic stroma, and pulmonary vasculature. In research subjects experiencing erectile dysfunction, sexual stimulation triggers nitric oxide (NO) release from penile endothelial and neuronal cells, activating guanylate cyclase and elevating intracellular cGMP concentrations in corpus cavernosum smooth muscle. Tadalafil inhibits PDE5-mediated cGMP degradation, prolonging and amplifying the cGMP-mediated smooth muscle relaxation cascade, facilitating increased arterial inflow into cavernosal tissue and supporting erectile function parameters. As with all PDE5 inhibitors, sexual stimulation is a prerequisite for tadalafil's erectile effects — the compound amplifies the physiological NO-cGMP signaling response to stimulation rather than initiating erection independently. Tadalafil's pharmacokinetic profile is characterized by an onset of action of approximately 30 minutes following oral administration, with a total duration of effect of up to 36 hours documented in clinical research — significantly extending the therapeutic window relative to sildenafil and vardenafil in comparative PDE5 inhibitor pharmacokinetic literature. This extended duration is attributed to tadalafil's distinct molecular structure conferring slower systemic clearance, with a plasma half-life of approximately 17.5 hours documented in pharmacokinetic research. In the context of benign prostatic hyperplasia, PDE5 expression has been documented in prostatic stromal smooth muscle, bladder detrusor muscle, and urethral smooth muscle, with tadalafil's inhibitory activity in these tissues associated with documented improvement in lower urinary tract symptom parameters — establishing Cialis as the only PDE5 inhibitor with a dual approved indication for both erectile dysfunction and BPH symptom management referenced in international clinical guidelines. Food consumption has been documented to have minimal effect on tadalafil absorption in pharmacokinetic research, a clinically relevant advantage relative to sildenafil noted in comparative PDE5 inhibitor literature.
 
⭐ Product Overview
Manufactured by Eli Lilly, the originator pharmaceutical company responsible for the development, clinical investigation, and regulatory approval of tadalafil as a PDE5 inhibitor — establishing the foundational clinical research base for the tadalafil compound class
Original reference brand formulation with the most extensively documented clinical trial and post-marketing surveillance history among all tadalafil preparations worldwide
Distinguished within the PDE5 inhibitor drug class by the longest documented plasma half-life of approximately 17.5 hours and corresponding therapeutic window of up to 36 hours in comparative pharmacokinetic research
Dual approved clinical indication for both erectile dysfunction and BPH-associated lower urinary tract symptom management, referenced in international urology guidelines — a distinction unique to tadalafil among approved PDE5 inhibitor compounds
Widely referenced as the originator compound in urological, cardiovascular, and pulmonary pharmacology research literature under the tadalafil and Cialis designations worldwide