A reference work, not a recommendation to use: this profile describes mechanism and evidence and does not replace medical advice. The claims come from marketing and forums and are tested here, not endorsed.

Claims checked

  • Better erections and more blood flow even without erectile dysfunction

    Not studied

    Libido & sexual function · healthy · No data

    No tadalafil RCT in men without erectile dysfunction with a sexual endpoint found. The only placebo-controlled study in young healthy people tested sildenafil (a different substance, does not count) and found no better erection [6]. That tadalafil does not trigger an erection without arousal is stated in the authorization [2]. Abstract only checked.

  • More performance in training

    Not studied

    Muscle & performance · healthy · No data

    No study tested tadalafil the way it is promised, i.e., over training sessions or a training phase. The three small placebo-controlled crossover studies found gave it only once or on two days before a single exertion test: VO2max as well as ventilatory and anaerobic threshold unchanged (14 athletes) [11]; anaerobic performance in the Wingate test not substantially changed (12 athletes) [10]; performance values unchanged as a secondary finding of a study on the stress hormone axis (14 men, randomized) [9]. Small studies that do not test the claim in the promised design carry no “No benefit” under the library's rating rules; the findings are in the text. Split off per K4 from the bundled advertising claim “More pump and performance in training”. Abstract only checked.

  • More pump (muscle blood flow) in training

    Not studied

    Muscle & performance · healthy · No data

    In no study found were muscle blood flow or “pump” measured; the sports studies recorded performance, cardiovascular, lactate, and hormone values [9][10][11]. Split off per K4 from the bundled advertising claim “More pump and performance in training”. Abstract only checked.[9][10][11]

  • Helps with erectile dysfunction

    Proven benefit

    Libido & sexual function · Patients: erectile dysfunction · Human, randomised manufacturer-fundedAccording to their funding or competing-interest statements, all studies behind this result were paid for, wholly or in part, by the maker of the product or compound, or list employees of the maker among their authors. Manufacturer-funded studies on average come out more favourably for the product.

    Integrated analysis of six placebo-controlled RCTs with 1913 men: clinically meaningful improvement of erectile function, also with comorbidities [5]; authorization in the EU [2]. The analysis comes from the manufacturer (authors at Eli Lilly or Lilly Deutschland). Study [5] abstract only checked.

manufacturer-funded: According to their funding or competing-interest statements, all studies behind this result were paid for, wholly or in part, by the maker of the product or compound, or list employees of the maker among their authors. Manufacturer-funded studies on average come out more favourably for the product.

Mechanism of action

Evidence map: Tadalafil

Each line stands for a published finding; line style and color show where it comes from. The filter hides weaker evidence levels. Sources: see references.

During sexual arousal, nerves and endothelium in the corpus cavernosum release nitric oxide, which relaxes smooth muscle via cGMP; phosphodiesterase 5 (PDE5), the predominant phosphodiesterase in the corpus cavernosum, breaks down cGMP [1]. Tadalafil inhibits PDE5 and thereby keeps cGMP elevated longer; without arousal it does not trigger an erection, which is why the authorization texts require sexual stimulation [2]. At the purified enzyme, tadalafil is about 40-fold more selective for PDE5 than for PDE11A4, while sildenafil and vardenafil are clearly more selective here; the authors nevertheless consider inhibition of PDE11 in humans unlikely (in vitro) [3]. The half-life is 17.5 hours, clearly more than that of sildenafil [4].

In the EU, tadalafil is authorized for the treatment of erectile dysfunction, for symptoms of benign prostatic enlargement, and for pulmonary arterial hypertension [2]. In an analysis prepared by the manufacturer Lilly of six placebo-controlled RCTs with 1913 men with erectile dysfunction, tadalafil given continuously improved erectile function in a clinically meaningful way, also in hypertension, heart disease, and lipid disorders [5].

For men without erectile dysfunction, no RCT was found that tested erection or sexual function with tadalafil. The only placebo-controlled study found on this used a different substance, sildenafil: in 60 young, healthy men, similar numbers reported a better erection under sildenafil and placebo, only the refractory time after orgasm was shorter [6]; this finding does not apply to tadalafil. Nevertheless, tadalafil is also taken without a medical reason: 4% of 1944 US students had used erectile dysfunction drugs at least once without an indication, often together with illegal drugs and with risky sexual behavior [7]; among men who have sex with men, the pooled prevalence in five cross-sectional studies was 24.4% [8].

In sport, tadalafil is promoted for “pump” and endurance. In a randomized crossover study with 14 healthy men whose main question was the stress hormone axis, it dampened the rise in ACTH and cortisol at maximal exertion, but changed neither cardiovascular nor performance values [9]; in 12 trained athletes, a single dose did not substantially change anaerobic performance values [10]. In a double-blind, placebo-controlled crossover study with 14 healthy athletes, VO2max as well as ventilatory and anaerobic threshold remained unchanged, and systolic blood pressure fell [11]. Muscle blood flow (“pump”) was not measured in any of these studies. In another randomized, double-blind crossover study in healthy men, markers of muscle damage (creatine kinase +75%) and oxidative damage (malondialdehyde +41%) were higher and the glutathione redox ratio lower under tadalafil than under placebo even before exertion; after exhaustive exertion the values remained higher (markers only) [12]. Six months of continuous use did not impair sperm production in men aged 45 and older [13]. With nitroglycerin, blood pressure fell more than under placebo up to 24 hours after the last tadalafil dose, but no longer after 48 hours [4]. A link with the optic nerve disease NAION could not be established in a meta-analysis of observational studies [14]; the EU prescribing information, in contrast, regards analyses of observational data as an indication of an increased NAION risk and also names priapism and sudden hearing loss [15]; for PDE5 inhibitors as a group, a meta-analysis found an increased melanoma risk, for tadalafil alone it was not significant [16]. In potency products declared as purely herbal, sildenafil, tadalafil, or both were found in 73.3% of samples, partly in medicinal amounts [17]; for the herbal, clearly weaker PDE5 inhibitor icariin, see its profile.

Targets

TargetTypeActionKey dataEvidence
Phosphodiesterase 5 (PDE5A)EnzymeInhibitorPDE5/PDE11A4 selectivity about 40-fold (purified enzyme); clinically enhanced nitrate effect up to 24 h Human, randomised[1][3][4]
Phosphodiesterase 11 (PDE11A4)EnzymeInhibitorabout 40-fold weaker than at PDE5; inhibition in humans unlikely according to the authors Laboratory[3]

Effect profile

Which signaling systems the compound affects according to current data. ↑ enhanced, ↓ dampened, ≈ modulated, ○ no effect; dots = evidence level.

  • Dopamineno data
  • Noradrenalineno data
  • Serotoninno data
  • Acetylcholineno data
  • Glutamate · AMPAno data
  • Glutamate · NMDAno data
  • GABAno data
  • Histamineno data
  • Orexinno data
  • Adenosineno data
  • Opioidsno data
  • Melatoninno data
  • Neurotrophinsno data
  • Blood flow↑ · Relaxation of corpora cavernosa and vessels; marked fall in blood pressure with nitrates[4][5]
  • Nitric oxide↑ · Enhances the NO-cGMP signaling cascade through inhibited cGMP breakdown; clinically documented by the enhanced effect of nitroglycerin[1][3][4]
  • Energy metabolismno data
  • Insulin · glucoseno data
  • Inflammation · oxidativeno data
  • Stress axis↓ · Smaller rise in ACTH and cortisol at maximal exertion (crossover study, 14 men)[9]
  • Testosterone axisno data
  • Endocannabinoidsno data
  • Autophagy · senescenceno data
  • Immune systemno data
  • Lipid metabolismno data
  • Coagulation · fibrinolysisno data
  • Methylationno data

Routes of administration and bioavailability

How much of a compound reaches the blood or target tissue depends on the route into the body and on the dosage form. All routes of administration explained

  • Oral (swallowed) · Film-coated tablet

    Half-life 17.5 hours; interaction with nitroglycerin detectable up to 24 hours [4].

    Human, randomised

Human studies

  • Tadalafil given continuously in erectile dysfunction

    integrated analysis of 6 RCTs, double-blind, placebo-controlled · Patients: erectile dysfunction for at least 3 months · n = 1913 · 12 weeks

    Measured: IIEF erectile function, SEP3

    Result: IIEF-EF +4.2 or +5.4 points versus placebo (p < 0.01); clinically meaningful also in hypertension and heart disease. Authors partly at Lilly.[5]

    Human, randomised

  • Stress hormones at maximal exertion

    randomized, double-blind crossover study · healthy (men) · n = 14 · 2 days per phase, 2 weeks washout

    Measured: ACTH, cortisol (main question); performance values

    Result: ACTH, cortisol, and corticosterone response ↓, β-endorphin ↑; no change in cardiovascular and performance values.[9]

    Human, randomised

  • Anaerobic performance in athletes

    double-blind, placebo-controlled crossover study (randomization not stated in the abstract) · healthy (trained athletes) · n = 12 · single dose, 1 week apart

    Measured: Wingate test, lactate

    Result: No substantial change in anaerobic performance; lactate slightly higher after 3 minutes, time to peak power slightly shorter.[10]

    Human, non-randomised

  • Endurance performance in athletes

    double-blind, placebo-controlled crossover study (randomization not stated in the abstract) · healthy (male athletes) · n = 14 · single dose per phase

    Measured: VO2max, ventilatory and anaerobic threshold, blood pressure, lactate

    Result: VO2max and thresholds unchanged; systolic blood pressure before and after exertion ↓; oxygen pulse at the ventilatory threshold ↓.[11]

    Human, non-randomised

  • Markers of muscle damage and oxidation

    randomized, double-blind, placebo-controlled crossover study · healthy (men) · 2 days per phase, 2 weeks washout

    Measured: CK, LDH, malondialdehyde, protein carbonyls, GSH/GSSG, IL-6 after exhaustive exertion

    Result: Even before exertion CK +75%, LDH +36%, MDA +41%, protein carbonyls +50%, GSH/GSSG −36% versus placebo; further higher after exertion (markers only).[12]

    Human, randomised

  • Sperm production under continuous use

    two RCTs, placebo-controlled · healthy men or mild erectile dysfunction, aged 45 and older · n = 421 · 6 months

    Measured: sperm concentration, count, motility, morphology, hormones

    Result: No adverse effects; common side effects headache, digestive complaints, back pain.[13]

    Human, randomised

  • Interaction with nitroglycerin

    randomized, placebo-controlled crossover study · men (volunteers) · n = 150 · 7 days per phase

    Measured: fall in blood pressure after nitroglycerin

    Result: Greater fall in blood pressure 4, 8, and 24 hours after tadalafil, no longer after 48 hours.[4]

    Human, randomised

Risks and warnings

  • Dangerous fall in blood pressure with nitrates

    With nitroglycerin, blood pressure fell markedly more than under placebo up to 24 hours after tadalafil; the EU prescribing information names use in people who take organic nitrates in any form as a contraindication, as well as the combination with guanylate cyclase stimulators such as riociguat [15]. Alkyl nitrites (“poppers”) were not studied in this study.

    Human, randomised

  • Common side effects

    Headache, digestive complaints, and back pain under six months of intake [13].

    Human, randomised

  • Melanoma (signal for the drug class)

    Meta-analysis of eight observational studies: increased melanoma risk for PDE5 inhibitors overall (OR 1.60; HR 1.10), not significant for tadalafil alone (OR 1.54; 95% CI 0.79–3.00) with very high heterogeneity; bias from lifestyle cannot be excluded in observational data [16].

    Human, non-randomised

  • Optic nerve disease (NAION)

    In four observational studies no established association (OR 1.16; 95% CI 0.89–1.52); in addition 50 case reports and 608 spontaneous reports for PDE5 inhibitors as a group [14]. The EU prescribing information regards analyses of observational data as an indication of an increased NAION risk in men with erectile dysfunction under PDE5 inhibitors; after NAION-related vision loss in one eye, tadalafil is contraindicated there [15].

    Human, non-randomised

  • Priapism

    The EU prescribing information names prolonged erections and priapism as a side effect; untreated priapism can damage penile tissue and lead to permanent loss of potency [15].

    Human, non-randomised

  • Sudden hearing loss

    According to the EU prescribing information, cases of sudden worsening or loss of hearing have been reported, partly with further risk factors such as age, diabetes, hypertension, or earlier hearing loss [15].

    Human, non-randomised

  • Cardiovascular events and contraindications

    According to the EU prescribing information, serious cardiovascular events (including heart attack, sudden cardiac death, stroke) have been reported from studies and after market introduction, mostly with pre-existing risk factors; a causal link has not been clarified. Tadalafil is contraindicated there, among others, after a recent heart attack or stroke, in unstable angina pectoris, heart failure from NYHA II, uncontrolled arrhythmias, hypotension, or uncontrolled hypertension. With alpha-1 blockers, blood pressure can fall symptomatically [15].

    Human, non-randomised

  • Higher markers of muscle damage and oxidation with exertion

    In a randomized crossover study, creatine kinase and oxidation markers were higher under tadalafil than under placebo before and after exhaustive exertion; clinical consequences were not studied (markers only) [12].

    Human, randomised

  • Recreational use and polysubstance use

    Use without an indication was associated in surveys with polysubstance use of illegal drugs and risky sexual behavior [7][8].

    Human, non-randomised

  • Adulterated “herbal” potency products

    73.3% of the examined products declared as natural contained sildenafil, tadalafil, or both, partly in amounts as in approved medicines or above; plus vardenafil and analogs [17].

    Human, non-randomised

Interactions

  • organic nitrates (e.g., nitroglycerin): Increased fall in blood pressure up to 24 hours after the last tadalafil dose [4].
  • strong CYP3A4 inhibitors (e.g., ritonavir, ketoconazole, itraconazole, erythromycin): Increased tadalafil exposure (AUC) according to the EU prescribing information [15].
  • Alpha-1 blockers (e.g., doxazosin) and riociguat: Symptomatic fall in blood pressure possible; the combination with doxazosin is not recommended in the EU prescribing information, the combination with riociguat is contraindicated [15].

Fact check: common claims

  • not supported

    “Tadalafil also gives healthy young men better erections”

    No tadalafil study in men without erectile dysfunction found; one RCT with sildenafil (a different substance) found no better erection than placebo [6].

  • not supported

    “Tadalafil increases athletic performance”

    In three small placebo-controlled crossover studies with single doses, no performance increase [9][10][11]; in another, markers of muscle damage and oxidation were higher after exertion [12]. Tadalafil has not been studied over a training phase.

  • partly supported

    “Tadalafil can make you blind”

    NAION can lead to vision loss in one eye. The meta-analysis of four observational studies found no established association [14]; the EU prescribing information, in contrast, regards observational data as an indication of an increased risk, lists NAION as a side effect, and contraindicates tadalafil after NAION-related vision loss [15]. A causal link has not been proven, but an increased risk is recognized by regulators.

  • partly supported

    “Potency drugs raise the risk of skin cancer”

    For PDE5 inhibitors as a group, an increased melanoma risk in observational studies; not significant for tadalafil alone, and confounders such as sun exposure are not excluded [16].

  • not supported

    “Tadalafil harms fertility”

    Two RCTs over six months found no adverse effects on sperm or reproductive hormones in men aged 45 and older [13].

Pharmacokinetics

Half-life
17.5 hours [4].

Legal status

Germany
Prescription-only as a medicinal product (AMVV Annex 1, entry “Tadalafil”, without exception) [18]. A status as a food is not verified; in dietary supplements declared as “natural”, tadalafil has been found as an undeclared additive [17]. Not listed in the Annex to the German Anti-Doping Act [19].
EU
Centrally authorized: Cialis (EMEA/H/C/000436, since November 12, 2002) for the treatment of erectile dysfunction, “not for use in women”; Tadalafil Lilly (EMEA/H/C/004666) additionally for symptoms of benign prostatic enlargement; Adcirca (EMEA/H/C/001021) for pulmonary arterial hypertension; plus generics [2].
USA
Approved by the FDA: according to Drugs@FDA, the tablets Cialis (NDA 021368, initial approval November 21, 2003; one strength discontinued) and Adcirca (NDA 022332, initial approval May 22, 2009) are on the market as prescription-only products [20]. Indications and generics not checked against a primary source.

Related compounds

Icariin (Epimedium, „Horny Goat Weed“)same class (German only)Sildenafilsame class (German only)

Open questions

  • Does tadalafil improve erection or sexual function in men without erectile dysfunction (no RCT found)?
  • Does the dampened stress hormone response at exertion have practical significance, and what are the consequences of the higher markers of muscle damage?
  • Is the melanoma signal an effect of the substance or of the users' lifestyle?

References

  1. Corbin JD. Mechanisms of action of PDE5 inhibition in erectile dysfunction. Int J Impot Res. 2004;16 Suppl 1:S4-7. doi:10.1038/sj.ijir.3901205 · PubMed
  2. European Medicines Agency. Medicines output – medicines JSON report: Cialis (tadalafil), EMEA/H/C/000436, zugelassen 12.11.2002; Tadalafil Lilly, EMEA/H/C/004666; Adcirca, EMEA/H/C/001021 [Internet]. Zeitstempel 24.10.2026, abgerufen am 24.10.2026. Verfügbar unter: https://www.ema.europa.eu/en/documents/report/medicines-output-medicines_json-report_en.json
  3. Weeks JL, Zoraghi R, Beasley A, Sekhar KR, Francis SH, Corbin JD. High biochemical selectivity of tadalafil, sildenafil and vardenafil for human phosphodiesterase 5A1 (PDE5) over PDE11A4 suggests the absence of PDE11A4 cross-reaction in patients. Int J Impot Res. 2005;17(1):5-9. doi:10.1038/sj.ijir.3901283 · PubMed
  4. Kloner RA, Hutter AM, Emmick JT, Mitchell MI, Denne J, Jackson G. Time course of the interaction between tadalafil and nitrates. J Am Coll Cardiol. 2003;42(10):1855-60. doi:10.1016/j.jacc.2003.09.023 · PubMed
  5. Porst H, Gacci M, Büttner H, Henneges C, Boess F. Tadalafil once daily in men with erectile dysfunction: an integrated analysis of data obtained from 1913 patients from six randomized, double-blind, placebo-controlled, clinical studies. Eur Urol. 2014;65(2):455-64. doi:10.1016/j.eururo.2013.09.037 · PubMed
  6. Mondaini N, Ponchietti R, Muir GH, Montorsi F, Di Loro F, Lombardi G, et al. Sildenafil does not improve sexual function in men without erectile dysfunction but does reduce the postorgasmic refractory time. Int J Impot Res. 2003;15(3):225-8. doi:10.1038/sj.ijir.3901005 · PubMed
  7. Harte CB, Meston CM. Recreational use of erectile dysfunction medications in undergraduate men in the United States: characteristics and associated risk factors. Arch Sex Behav. 2011;40(3):597-606. doi:10.1007/s10508-010-9619-y · PubMed
  8. Tienforti D, Moretto C, Spagnolo L, Ciriani A, Cocci E, Perfetto E, et al. Beyond erectile dysfunction: recreational use of PDE5 inhibitors among men who have sex with men-a systematic review and meta-analysis. J Sex Med. 2026;23(8):qdag230. doi:10.1093/jsxmed/qdag230 · PubMed
  9. Di Luigi L, Sgrò P, Baldari C, Gallotta MC, Emerenziani GP, Crescioli C, et al. The phosphodiesterases type 5 inhibitor tadalafil reduces the activation of the hypothalamus-pituitary-adrenal axis in men during cycle ergometric exercise. Am J Physiol Endocrinol Metab. 2012;302(8):E972-8. doi:10.1152/ajpendo.00573.2011 · PubMed
  10. Guidetti L, Emerenziani GP, Gallotta MC, Pigozzi F, Di Luigi L, Baldari C. Effect of tadalafil on anaerobic performance indices in healthy athletes. Br J Sports Med. 2008;42(2):130-3. doi:10.1136/bjsm.2007.037630 · PubMed
  11. Di Luigi L, Baldari C, Pigozzi F, Emerenziani GP, Gallotta MC, Iellamo F, et al. The long-acting phosphodiesterase inhibitor tadalafil does not influence athletes' VO2max, aerobic, and anaerobic thresholds in normoxia. Int J Sports Med. 2008;29(2):110-5. doi:10.1055/s-2007-965131 · PubMed
  12. Ceci R, Duranti G, Sgrò P, Sansone M, Guidetti L, Baldari C, et al. Effects of tadalafil administration on plasma markers of exercise-induced muscle damage, IL6 and antioxidant status capacity. Eur J Appl Physiol. 2015;115(3):531-9. doi:10.1007/s00421-014-3040-5 · PubMed
  13. Hellstrom WJ, Overstreet JW, Yu A, Saikali K, Shen W, Beasley CM Jr, et al. Tadalafil has no detrimental effect on human spermatogenesis or reproductive hormones. J Urol. 2003;170(3):887-91. doi:10.1097/01.ju.0000081053.97792.da · PubMed
  14. Penedones A, Alves C, Batel Marques F. Risk of nonarteritic ischaemic optic neuropathy with phosphodiesterase type 5 inhibitors: a systematic review and meta-analysis. Acta Ophthalmol. 2020;98(1):22-31. doi:10.1111/aos.14253 · PubMed
  15. European Medicines Agency. CIALIS (Tadalafil): EPAR – Produktinformation, Anhang I: Zusammenfassung der Merkmale des Arzneimittels (Fachinformation), EMEA/H/C/000436 [Internet]. Abgerufen am 24.10.2026. Verfügbar unter: https://www.ema.europa.eu/de/documents/product-information/cialis-epar-product-information_de.pdf
  16. Kreuz M, Moraes FCA, Lôbo AOM, Skov RPH, Pincelli TP. Updated meta-analysis on the risk of melanoma associated with phosphodiesterase type 5 inhibitors. Melanoma Res. 2025;35(5):293-299. doi:10.1097/CMR.0000000000001049 · PubMed
  17. Gheorghiu ORC, Ciobanu AM, Guțu CM, Chițescu CL, Costea GV, Anghel DM, et al. Determination of Phosphodiesterase Type-5 Inhibitors (PDE-5) in Dietary Supplements. Molecules. 2023;28(10):4116. doi:10.3390/molecules28104116 · PubMed
  18. Verordnung über die Verschreibungspflicht von Arzneimitteln (Arzneimittelverschreibungsverordnung – AMVV), Anlage 1 (zu § 1 Nr. 1 und § 5). Bundesministerium der Justiz [Internet]. Abgerufen am 24.10.2026. Verfügbar unter: https://www.gesetze-im-internet.de/amvv/anlage_1.html
  19. Gesetz gegen Doping im Sport (Anti-Doping-Gesetz – AntiDopG), Anlage (zu § 2 Absatz 3). Fundstelle: BGBl. 2023 I Nr. 67, S. 1–5. Bundesministerium der Justiz [Internet]. Abgerufen am 24.10.2026. Verfügbar unter: https://www.gesetze-im-internet.de/antidopg/anlage.html
  20. U.S. Food and Drug Administration. Drugs@FDA (openFDA-Abfrage): Tadalafil, NDA 021368 Cialis (Tabletten) „Prescription“ (ein Produkt „Discontinued“), Originalzulassung (ORIG, AP) 21.11.2003; NDA 022332 Adcirca (Tabletten) „Prescription“, Originalzulassung (ORIG, AP) 22.05.2009 [Internet]. Silver Spring (MD): FDA; Datenstand 23.10.2026, abgerufen am 25.10.2026. Verfügbar unter: https://api.fda.gov/drug/drugsfda.json?search=application_number:NDA021368
How this profile was checked

Last reviewed: 2026-10-25. All sources with a DOI or PMID were resolved automatically via Crossref or doi.org and PubMed.

Translated from the German profile (version of 2026-10-25); translation checked on 2026-10-26.

Checked

  • All abstracts read via PubMed (efetch); DOIs and PMIDs resolved online with tools/pruefe_profile.py.
  • At the abstract: NO-cGMP pathway, PDE5 as the predominant phosphodiesterase in the corpus cavernosum (review) [1]; PDE5A1/PDE11A4 selectivity 40-fold (tadalafil), 9300-fold (vardenafil), 1000-fold (sildenafil), cross-reactivity in the patient unlikely according to the authors [3]; t½ 17.5 h, n = 150, fall in blood pressure after nitroglycerin at 4/8/24 h, not at 48–96 h [4]; 1913 men, IIEF-EF +4.2/+5.4, three authors at Lilly Deutschland [5]; sildenafil, 60 young healthy people, 12/30 vs. 10/30, refractory time p = 0.04 [6]; 1944 students, 4% lifetime, 1.4% current [7]; 5 cross-sectional studies, 4390 people, 24.4% (16.7–34.2%) [8]; 14 men, ACTH/cortisol ↓, performance unchanged [9]; 12 athletes, no substantial change [10]; 421 men ≥ 45 years, 6 months, no sperm damage [13]; NAION OR 1.16 (0.89–1.52), 50 case reports, 608 spontaneous reports [14]; melanoma OR 1.60, HR 1.10, tadalafil OR 1.54 (0.79–3.00) [16]; 73.3% adulterated, amounts as in medicines or higher [17].
  • Cross-check October 24, 2026 (abstracts via PubMed efetch): 14 healthy athletes, double-blind, crossover, VO2max, ventilatory and anaerobic threshold unchanged, systolic blood pressure ↓, randomization not stated [11]; healthy men, randomized, double-blind, crossover, CK +75%, LDH +36%, MDA +41%, protein carbonyls +50%, GSH/GSSG −36%, n not in the abstract [12]; [9] main question stress axis, “without influencing cardiorespiratory and performance parameters”; [10] “double-blinded”, randomization not stated, therefore level 3 in “studien_mensch”.
  • EU prescribing information CIALIS (EPAR product information, German) read on October 24, 2026: contraindications (nitrates, riociguat, cardiovascular groups, NAION), warnings on cardiovascular events, alpha-1 blockers/doxazosin, NAION (observational data suggest an increased risk), sudden hearing loss, priapism, CYP3A4 inhibitors [15].
  • Targeted PubMed searches on October 24, 2026 for RCTs with tadalafil in men without erectile dysfunction and a sexual endpoint (including “tadalafil[ti] AND (healthy OR volunteers) AND (erection OR erectile OR sexual) AND randomized”, 9 hits): none found; hits concerned pharmacokinetics, interactions, and sperm.
  • EMA medicines export (timestamp October 24, 2026): Cialis EMEA/H/C/000436 (authorized November 12, 2002; indication erectile dysfunction, not in women), Tadalafil Lilly EMEA/H/C/004666 (ED and BPH), Adcirca EMEA/H/C/001021 (PAH), plus generics and Yuvanci (combination) [2].
  • AMVV Annex 1 read on October 24, 2026: entry “Tadalafil” [18]. AntiDopG Annex: not listed [19].
  • PubChem CID 110635.
  • October 25, 2026, decision q006 (Tilman: K4 reading, small RCTs do not carry “No benefit”): abstracts of [9], [10], and [11] reread via PubMed efetch. [9]: administration on two days before a single maximal exertion, crossover, 14 men; [10]: single dose the day before a Wingate test, 12 trained people; [11]: single dose before a step test, 14 athletes. No study tested a training phase. “More performance in training” therefore from level 4 “No benefit” to level 0 “Not studied”; short summary, evidenz_gesamt, evmap, and claim adjusted, findings remain in the text.
  • October 25, 2026, decision q012 (abstract only checked): all ratings from journal articles ([1], [3] to [14], [16], [17]) are based only on the abstracts; full texts were not read. Read in the original wording were the EU prescribing information [15], the EMA export [2], and the statutory texts [18], [19].
  • October 25, 2026, decision q018 (trade names): “Adcirca” added (EMEA/H/C/001021 according to the EMA export [2]; Drugs@FDA NDA022332, queried via the openFDA interface api.fda.gov/drug/drugsfda.json on October 25, 2026); “Cialis” was already included (EMEA/H/C/000436 [2]; Drugs@FDA NDA021368). Generics and combination products not included.
  • October 25, 2026, decision q075: “Tadalafil can make you blind” remains “partly supported” (EU prescribing information [15]); decision q099: cross-link to icariin with “same class” (shared target PDE5) remains.
  • October 25, 2026, decision q040: rx_referenz set (package P1, prescription requirement according to AMVV Annex 1 [18]).
  • October 25, 2026, legal status (FDA identifiers): Drugs@FDA queried directly via openFDA (data as of October 23, 2026, query October 25, 2026): NDA 021368 Cialis (tablets) “Prescription”, one product “Discontinued”, ORIG AP November 21, 2003; NDA 022332 Adcirca (tablets) “Prescription”, ORIG AP May 22, 2009 [20]. status.usa changed from “nicht verifiziert” to this primary source; the contradiction with the trade name note (q018), which already named the NDA, is thereby resolved.
  • October 26, 2026, precision flags (m004; rules in the guideline under “Zahlenregel und Präzisions-Flags”, implemented by Claude pending confirmation by Tilman): “Helps with erectile dysfunction”: “herstellerfinanziert” – [5] authors with affiliation Lilly Deutschland or Eli Lilly (PubMed). Cross-check October 26, 2026: evidence for the flags (participant numbers, direction, funding) carried over into the rationale and rechecked against abstracts or full texts.

Not verified

  • Frequency statements from the adverse reaction table of the EPAR product information were not adopted because the table in the evaluated PDF text could not be unambiguously assigned to the columns. The statement that sexual stimulation is necessary is also in section 4.1 of the prescribing information.
  • Manufacturer involvement in [4] and [13]: the abstracts name no company affiliation; not checked in the full text.
  • US indications and US generics not checked.

No dosages, no sources of supply. This information does not replace medical advice.

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