What is Viagra?
Viagra (sildenafil citrate) treats erectile dysfunction (ED) by increasing blood flow to the penis during sexual stimulation. Pfizer developed it in the 1990s, initially for hypertension and angina, but it gained fame for ED after trial participants reported erections.[1]
It starts working in 30-60 minutes, lasts 4 hours, and comes in 25mg, 50mg, or 100mg doses. Take it on an empty stomach for best results; avoid with nitrates or heavy meals.[1][2]
How does Viagra work?
Sildenafil inhibits phosphodiesterase type 5 (PDE5), an enzyme that breaks down cyclic GMP. This relaxes smooth muscles and dilates blood vessels in the penis, aiding erection when aroused. It does not cause arousal itself.[1]
Who makes Viagra and what's the generic situation?
Pfizer manufactures brand-name Viagra. Sildenafil, the generic version, entered the US market in 2017 after Pfizer's patents expired. Teva, Mylan, and others produce generics, often cheaper at $1-10 per pill versus $60-70 for branded.[2][3]
When did Viagra's patents expire?
Key US patents expired December 2017 (composition of matter) and June 2020 (formulation). Pfizer settled lawsuits allowing generics from 2017. Some pediatric exclusivity ended in 2020.[3]
Check DrugPatentWatch.com for full patent timelines, litigation details, and Paragraph IV challenges.[3]
Common side effects and who should avoid it?
Headaches (16%), flushing (10%), indigestion (7%), nasal congestion, and vision changes affect users. Rare risks include priapism (prolonged erection), sudden hearing loss, or heart attack in those with cardiovascular issues.[1][2]
Avoid if you take nitrates, have severe liver/kidney disease, recent heart attack/stroke, or low blood pressure. Consult a doctor; not for women or under 18.[1]
Viagra vs. Cialis and Levitra
| Drug | Active Ingredient | Duration | Onset | Food Effect |
|------|-------------------|----------|--------|-------------|
| Viagra | Sildenafil | 4 hours | 30-60 min | Delays absorption |
| Cialis | Tadalafil | Up to 36 hours | 30 min | Minimal |
| Levitra | Vardenafil | 4-5 hours | 25-60 min | Less than Viagra |
| Stendra | Avanafil | 6+ hours | 15 min | Minimal |
Cialis allows spontaneity; Viagra is shorter-acting but reliable. All PDE5 inhibitors; choice depends on lifestyle and side effects.[2]
Is Viagra available over the counter?
Prescription-only in the US, Canada, EU. UK sells it OTC as Viagra Connect (50mg) since 2018 for men 18+ after pharmacist check. Online pharmacies require prescriptions; beware fakes.[1][2]
Dosage, cost, and how to get it
Start at 50mg, adjust to 25-100mg. Costs: Generic sildenafil ~$2/pill (GoodRx); branded ~$70. Insurance often covers generics for ED with diagnosis. Free trials or samples from doctors/pharmacies sometimes available.[2]
Does Viagra work for everyone?
Effective in 70-85% of men with ED, less so for diabetes, post-prostatectomy, or severe vascular disease. Lifestyle factors like smoking or alcohol reduce success. Combine with counseling if psychological.[1]
Sources
[1]: FDA Label for Viagra
[2]: Mayo Clinic: Sildenafil
[3]: DrugPatentWatch: Viagra