CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-07-19). The draft was written by AI, the existence of all 3 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.6.
Verdict No. 629 · Search date 2026-07-19 · Methodology v0.6

Sildenafil,
does it really help with Improved erectile function and intercourse success in men with erectile dysfunction?

30-Second Summary
B
Evidence Grade B · 79 · Safety unknown
Sildenafil markedly improves erections and intercourse success but is not an aphrodisiac and must never be combined with nitrates
What the
research shows
Sildenafil is rated B because it consistently improves erectile function and intercourse success in men with erectile dysfunction. In a meta-analysis of 27 randomized trials and 6,659 men, 57% of intercourse attempts were successful with sildenafil versus 21% with placebo, and 83% versus 45% of men had at least one success during treatment. These are strong, repeated, patient-centered clinical outcomes, but industry concentration in early trials and limitations from subjective reporting and selected trial populations prevent the strict independent large-trial standard for A. Hypotension with nitrates, cardiovascular suitability, visual or auditory events, and counterfeit products are safety issues kept separate from efficacy.
What the
ads claim
Illicit sales and advertising can expand the evidence into explosive desire, higher testosterone, or a universally safe performance enhancer. Sildenafil is a prescription medicine that supports erectile response to sexual stimulation; it has not been shown to exceed normal function or resolve relationship problems or hormonal deficiency.
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Useful facts when choosing a product

  • Sildenafil inhibits PDE5 and enhances penile blood-flow response during sexual stimulation. It is not an aphrodisiac and does not raise libido or testosterone.
  • For erectile dysfunction it is usually taken as needed before sexual activity, with dose and interval adjusted for age, renal or hepatic function, and interacting medicines. Individual prescribing instructions and the current label take priority.
  • Combination with any nitrate, including nitroglycerin or isosorbide, is contraindicated because of severe hypotension. Alpha blockers and strong CYP3A inhibitors also require caution and dose adjustment.
  • Unofficial online products may be counterfeit with uncertain ingredients or strength. Licensed prescribing and dispensing channels should be used, and an erection lasting over four hours or sudden vision or hearing loss requires emergency evaluation.
Gap Measurement · Verdict 629 · B 79
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

The synthesis of 27 trials compared sildenafil with control for at least seven days and assessed clinically relevant erectile and intercourse outcomes. The absolute difference in successful intercourse attempts was about 34 percentage points, and erectile function improved over placebo in every evaluated subgroup. Two double-blind Goldstein 1998 trials confirmed dose response on the IIEF erectile domain and intercourse success. This differs from verdict 590 on tadalafil for benign-prostatic-hyperplasia urinary symptoms in both ingredient and claimed outcome; the present verdict addresses erection and intercourse success in erectile dysfunction.

02

Why this is classified as B (79)

Across 27 randomized trials and 6,659 men, successful intercourse attempts were 57% versus 21%, at least one success occurred in 83% versus 45%, and IIEF improvement was consistent, producing an effect close to A. Industry concentration in development trials, short follow-up, and reliance on subjective reporting prevent the independence standard for A, yielding the top of B with 79 points. Aphrodisiac effects remain separately unproven, while nitrate contraindication and other safety risks remain distinct.

Counterpoint. After confirming cardiovascular suitability and contraindications, sildenafil is a highly effective first-line oral option for correctly diagnosed erectile dysfunction. Nonresponse calls for review of timing, stimulation, dose, diabetes, vascular disease, medicines, hormones, and psychological factors.

Rejudgment record. New verdict — Applied the top of B because intercourse success and IIEF improved strongly and consistently across 27 randomized trials and 6,659 men, approaching A, but industry concentration, short follow-up, and reliance on subjective reporting fail the independence requirement

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
Improved erectile function and intercourse success in men with erectile dysfunctionBDirect patient-centered outcomes improved strongly and consistently across 27 randomized trials and 6,659 men.
Aphrodisiac effects that increase libido or testosterone?Sildenafil supports erectile response during sexual stimulation, but the trials do not establish increased libido or testosterone.
Risks from nitrate coadministration and counterfeit products?These are major safety and supply-chain issues: nitrates are contraindicated and licensed dispensing channels should be used.

Cross-check — Codex and Claude

This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
03

Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Fink HA et al. 2002Systematic review and meta-analysis of randomized trials6,659United States Department of Veterans Affairs and academic support; many included trials were industry-fundedIIEF erectile function, successful intercourse attempts, treatment response, and adverse eventsSildenafil was superior, with 57% versus 21% successful intercourse attempts and 83% versus 45% of men achieving at least one success.Key large synthesis of direct clinical efficacy
Goldstein I et al. 1998Two sequential double-blind randomized placebo-controlled trials329PfizerIIEF erectile-function domain and successful intercourse attemptsA dose response was observed, and 69% versus 22% of intercourse attempts succeeded during the final four weeks of the dose-escalation trial.Representative direct randomized evidence with sponsor funding
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Receipt — 3 References

All 3 cited sources were verified for existence at the original page (as of 2026-07-19).

Fink HA, Mac Donald R, Rutks IR, Nelson DB, Wilt TJ. Sildenafil for male erectile dysfunction: a systematic review and meta-analysis. Arch Intern Med. 2002;162(12):1349-1360. PMID: 12076233. DOI: 10.1001/archinte.162.12.1349.
checked
Goldstein I, Lue TF, Padma-Nathan H, Rosen RC, Steers WD, Wicker PA. Oral sildenafil in the treatment of erectile dysfunction. N Engl J Med. 1998;338(20):1397-1404. PMID: 9580646. DOI: 10.1056/NEJM199805143382001.
checked
U.S. Food and Drug Administration. VIAGRA (sildenafil citrate) Prescribing Information. PMID: none. DOI: none.
checked
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-19 · Corrections: none

Cite this verdict

Sildenafil x improved erectile function and intercourse success Evidence Grade B card
[Chamgap] Sildenafil x improved erectile function and intercourse success — Evidence Grade B·79. 3 cited sources checked. Source: https://chamgap.com/en/verdicts/mens/sildenafil-erectile-function-intercourse-success/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

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What this document does and does not do

Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.