Rankings / Hormones & Endocrine
Sildenafil (Viagra)
Hormones & Endocrine · PDE5 inhibitor
Tier A
Bottom line
Read Off Label grades Sildenafil (Viagra) as A (8.0/10) based on very strong evidence, very strong benefit magnitude, and a low-med-risk safety profile.
Generic since 2017 — dramatic price drop.
Studied, labeled, or reported-use context: 25-100 mg PO 30-60 min before activity; fasting administration produces faster onset — Rx; generics widely available; Hims/Roman-style telehealth; not individualized guidance.
What the evidence says
Generic since 2017 — dramatic price drop. Fang 2021 and others show observational Alzheimer risk reduction in PDE5i users — mechanism via cerebral blood flow and Aβ modulation plausible. A high-fat meal delays absorption by more than one hour. Concomitant nitrates can cause severe hypotension and are contraindicated in prescribing information. A sildenafil oral film (Vybrique) gained FDA approval in 2026 as a more convenient dosing format.
Mechanism
Selective phosphodiesterase-5 inhibitor; prevents cGMP breakdown → sustained smooth muscle relaxation in corpus cavernosum → erection (upon sexual stimulation, not spontaneous); also pulmonary vasodilation
Studied, labeled, or reported dose & route
25-100 mg PO 30-60 min before activity; fasting administration produces faster onset
This records doses and routes described in studies, approved labeling, clinical practice, or documented use. It is not individualized guidance and does not establish safety; context changes with indication, formulation, health history, monitoring, and other medicines.
Citations
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Common questions
- What does the evidence show about Sildenafil (Viagra)'s effects?
- Read Off Label rates the evidence for Sildenafil (Viagra) as Very Strong and the benefit magnitude as very strong, producing an overall grade of A (8.0/10). Generic since 2017 — dramatic price drop.
- What safety findings are reported for Sildenafil (Viagra)?
- Sildenafil (Viagra) has a low-med risk profile in the database. Low-Med (headache, flushing, nasal congestion, dyspepsia, blue-tinge vision; contraindicated with nitrates — fatal hypotension; caution with alpha-blockers) Legal status: Rx; generics widely available; Hims/Roman-style telehealth.
- What doses or routes are reported for Sildenafil (Viagra)?
- 25-100 mg PO 30-60 min before activity; fasting administration produces faster onset This is context from studies, approved labeling, clinical practice, or documented use; it is not individualized guidance and does not establish safety.
- How does Sildenafil (Viagra) work?
- Selective phosphodiesterase-5 inhibitor; prevents cGMP breakdown → sustained smooth muscle relaxation in corpus cavernosum → erection (upon sexual stimulation, not spontaneous); also pulmonary vasodilation
This is an independent synthesis of published research by a non-clinician. Scores are opinions supported by citations, not prescriptions. See the full disclaimer and methodology for how this score was produced and what it does and doesn't mean.