Viagra 100 mg by Pfizer is the original pharmaceutical-grade oral sildenafil citrate formulation at its maximum approved dose, supplied as film-coated tablets in boxes of 4 at 100 mg per tablet. As the originator brand under which sildenafil was first developed, clinically investigated, and approved for erectile dysfunction pharmacotherapy, Pfizer's Viagra 100 mg represents the highest documented therapeutic dose in international erectile dysfunction management guidelines and the most extensively researched sildenafil concentration in comparative PDE5 inhibitor clinical literature.
 
✔ Key Research Insights
Studied for its role in inhibiting phosphodiesterase type 5 enzyme activity in penile corpus cavernosum smooth muscle at the 100 mg dose, with documented enhancement of cGMP-mediated vasodilation and associated improvement in erectile function parameters in research subjects with erectile dysfunction, including those with more refractory presentations inadequately responsive to lower dose protocols
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 at the 100 mg dose across extensively documented subject populations, with established efficacy superiority over both placebo and lower sildenafil doses in subpopulations with more significant erectile dysfunction severity referenced in international urology clinical literature
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 100 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 maximum approved dose in international clinical guidelines for erectile dysfunction management, indicated for subjects with insufficient response to the standard 50 mg starting dose
 
📦 Product Specifications
Manufacturer: Pfizer
Product: Viagra
Molecule: Sildenafil Citrate
Drug Class: Phosphodiesterase Type 5 (PDE5) Inhibitor
Concentration: 100 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. The 100 mg dose is documented in comparative dose-response research as producing greater magnitude of PDE5 inhibition and correspondingly enhanced erectile function outcomes relative to the 25 mg and 50 mg doses, and is referenced in international guidelines as the appropriate dose for subjects with insufficient clinical response to the standard 50 mg starting protocol. 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. 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, a clinically relevant consideration at the 100 mg dose level.
 
⭐ 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 at the maximum approved 100 mg dose, with the most extensively documented clinical trial history among all sildenafil dose presentations worldwide
Maximum approved dose per international erectile dysfunction pharmacotherapy guidelines, indicated for subjects with documented insufficient response to lower dose protocols
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 and dose-response benchmark in urological, cardiovascular, and pulmonary pharmacology research literature under the sildenafil citrate and Viagra designations worldwide