Viagra 50 mg by Pfizer is the original pharmaceutical-grade oral sildenafil citrate formulation — the reference brand under which sildenafil was first developed, clinically investigated, and approved for erectile dysfunction pharmacotherapy. Supplied as film-coated tablets in boxes of 4 at 50 mg per tablet, Pfizer's Viagra represents the most extensively documented brand in PDE5 inhibitor clinical research literature, with a regulatory and pharmacological history spanning decades across urology, cardiovascular medicine, and pulmonary pharmacology.
 
✔ 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
Investigated in its original cardiovascular research context for systemic hypertension and angina management, with its selective PDE5 inhibitory profile and vasodilatory mechanism first documented in Pfizer-sponsored early-phase cardiovascular pharmacology trials
Researched for its clinical efficacy in erectile dysfunction across the most extensively documented subject populations of any PDE5 inhibitor compound, with established efficacy superiority over placebo referenced consistently across international urology clinical guidelines
Examined for its pulmonary arterial vasodilatory effects via PDE5 inhibition in pulmonary vascular smooth muscle, representing a clinically distinct and well-established therapeutic application documented in cardiovascular and pulmonary medicine literature
Documented for its pharmacokinetic profile at the 50 mg dose, with onset of action of approximately 30–60 minutes and duration of effect of 4–6 hours referenced in comparative PDE5 inhibitor research literature
Referenced as the originator compound across international clinical guidelines as a first-line pharmacological intervention for erectile dysfunction management
 
📦 Product Specifications
Manufacturer: Pfizer
Product: Viagra
Molecule: Sildenafil Citrate
Drug Class: Phosphodiesterase Type 5 (PDE5) Inhibitor
Concentration: 50 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
Sildenafil citrate 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 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. Sildenafil 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 sildenafil's erectile effects — the compound amplifies the physiological NO-cGMP signaling response to stimulation rather than initiating erection independently. The 50 mg dose represents the standard recommended starting dose referenced across international erectile dysfunction management guidelines, with upward or downward titration to 100 mg or 25 mg documented as clinically appropriate based on individual response and tolerability parameters. Sildenafil's pharmacokinetic profile is characterized by an onset of action of approximately 30–60 minutes following oral administration and a total duration of effect of approximately 4–6 hours in research subjects, with food consumption — particularly high-fat meals — documented to delay absorption and reduce peak plasma concentration in pharmacokinetic research.
 
⭐ Product Overview
Manufactured by Pfizer, the originator pharmaceutical company responsible for the discovery, development, and regulatory approval of sildenafil as a PDE5 inhibitor — establishing the foundational clinical research base for the entire PDE5 inhibitor drug class
Original reference brand formulation with the most extensively documented clinical trial and post-marketing surveillance history among all sildenafil preparations worldwide
Standard 50 mg starting dose consistent with international erectile dysfunction pharmacotherapy guidelines, supporting individualized dose titration per clinical protocol
Dual therapeutic application documented in clinical literature — erectile dysfunction and pulmonary arterial hypertension — under the sildenafil and Viagra designations
Widely referenced as the originator compound in urological, cardiovascular, and pulmonary pharmacology research literature under the sildenafil citrate and Viagra designations worldwide