Tadalafil is a long-acting phosphodiesterase type 5 inhibitor, the active ingredient of Cialis for erectile dysfunction and benign prostatic hyperplasia.
Amounts reported for Tadalafil are listed under Reported protocols, each with its source and study kind. No amount ladder is inferred from them. This is educational source context, not a protocol or recommendation.
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Human study rows are described per source under Reported protocols; they belong to their trial populations and are not a general amount.
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What published studies and recent community write-ups report about amounts, timing and course length. 2 clinical and 2 community-reported rows, each linked to its source. These are descriptions of what others report, not instructions, and nothing here is medical advice.
| Context | Dose | Frequency | Route | Course | Source |
|---|---|---|---|---|---|
| Clinical2 rows | |||||
| FDA label (Cialis): erectile dysfunction and benign prostatic hyperplasiaAdult men with erectile dysfunction, BPH symptoms or both | As needed: 10 mg to start, adjusted between 5 mg and 20 mg; once daily: 2.5 mg to start, may increase to 5 mg; BPH or ED plus BPH: 5 mg | Not more than once per day for as-needed use; once daily at about the same time for daily use | Oral tablets (5, 10 and 20 mg), with or without food | Open-ended as prescribedNone described | DailyMed, National Library of Medicine (originator label)2026 |
| The label notes that a single as-needed dose improves erectile function for up to 36 hours and sets hard limits with interacting drugs: no more than 10 mg every 72 hours as needed, or 2.5 mg daily, with strong CYP3A4 inhibitors, and no more than 5 mg every 72 hours when creatinine clearance is below 30 mL/min. Nitrates and riociguat are contraindicated, and the label warns about hypotension with alpha-blockers and heavy alcohol. | |||||
| Integrated analysis of six randomized once-daily trials1,913 men with at least 3 months of erectile dysfunction (596 placebo, 394 on 2.5 mg, 923 on 5 mg) | 2.5 mg or 5 mg | Once daily | Oral | 12 weeksNot applicable | European Urology (PubMed)2014 |
| Both doses improved erectile function scores and successful-intercourse rates against placebo, with the 5 mg dose reaching the minimal clinically important difference in harder subgroups such as obese men, smokers and psychogenic ED. The authors, several of them employees of the manufacturer, describe the results as descriptive pooled data rather than new trial evidence. | |||||
| Community-reported2 rows | |||||
| Research-database quick reference | 5 mg daily or 10-20 mg as needed | Once daily or as needed, at most once per 24 hours | Oral; the page is built around liquid research solutions measured by volume | Ongoing as prescribed; the page states no cycling is requiredNone | Community resource2026 |
| This peptide-database entry simply restates the labeled doses for people measuring a liquid product, quoting a half-life of about 17.5 hours and room-temperature storage. Its only addition to the label is the volume math for a given concentration; it is a community reference, not a study. | |||||
| Research-vendor liquid listing (format only) | 20 mg/mL liquid suspension as labeled; a third-party assay of one lot measured 25.23 mg/mL | Not stated | Oral liquid, sold for laboratory research only | Not statedNot stated | Community resource2026 |
| This is a vendor page, not a protocol. The published certificate shows the lot running about 26% over its labeled concentration, so a volume calculated from the label would deliver more drug than intended. The same vendor sells 5 mg capsules of amino tadalafil, a different molecule with its own CAS number, so a buyer comparing the two products is not comparing two forms of the same compound. | |||||
Plus 3 community resources (dosing guides, forum threads and vendor write-ups), reported above but not linked.
Tadalafil is a long-acting phosphodiesterase type 5 inhibitor, the active ingredient of Cialis for erectile dysfunction and benign prostatic hyperplasia and of Adcirca for pulmonary arterial hypertension. It is an oral small molecule from the beta-carboline family whose long half-life is why it is the one PDE5 inhibitor labeled for daily use as well as on-demand dosing, and it has been a prescription medicine since 2003. Research vendors sell it as a liquid suspension and also sell capsules of amino tadalafil, which is a structurally different analog (CAS 385769-84-6, formula C21H18N4O4) with no approved use that has turned up as an undeclared ingredient in adulterated consumer products, so the two should not be confused.
These themes describe recurring questions in published research. They are not claims of effectiveness or recommendations for use.
Hormonal, reproductive and sexual-function research.
The label notes that a single as-needed dose improves erectile function for up to 36 hours and sets hard limits with interacting drugs: no more than 10 mg every 72 hours as needed, or 2.5 mg daily, with strong CYP3A4.
Both doses improved erectile function scores and successful-intercourse rates against placebo, with the 5 mg dose reaching the minimal clinically important difference in harder subgroups such as obese men, smokers and.
This peptide-database entry simply restates the labeled doses for people measuring a liquid product, quoting a half-life of about 17.5 hours and room-temperature storage. Its only addition to the label is the volume.
This is a vendor page, not a protocol. The published certificate shows the lot running about 26% over its labeled concentration, so a volume calculated from the label would deliver more drug than intended. The same.
Study models remain visible so laboratory and animal findings are not mistaken for established human outcomes.
2 protocol rows on this page come from human trials, trial registrations, regulator labels or reviews of human data. Approval status and populations are stated per row.
2 rows record what blogs, vendor write-ups or forums describe for Tadalafil. None has been verified against primary literature.
Sequence, synonyms and registry identifiers as recorded in PubChem, the National Library of Medicine's open chemistry database. Formula, mass and CAS number are summarized at the top of the page.
Cialis, Adcirca, IC-351, LY-450190, Tadalafilo, UNII 742SXX0ICT, CHEBI:71940, NSC-750236
WOXKDUGGOYFFRN-IIBYNOLFSA-N
(2R,8R)-2-(1,3-benzodioxol-5-yl)-6-methyl-3,6,17-triazatetracyclo[8.7.0.03,8.011,16]heptadeca-1(10),11,13,15-tetraene-4,7-dione
3 curated references, each with its journal, year and study model, plus 3 community resources reported but not linked.