Tadalafil and dapoxetine together: what the two trials measured

Two molecules, sold together in one tablet, and the indexed human record for the pair turns out to split cleanly in two. Two papers randomised people. Six papers are about measuring chemistry. This page reports both halves, because the split is the useful fact.

The three-arm trial

The 2024 paper in Arab Journal of Urology is the more recent and the larger. Men attending an andrology clinic with premature ejaculation were randomised into three groups: group A, 92 participants, on-demand tadalafil 5 mg; group B, 91 participants, on-demand dapoxetine 30 mg; group C, 89 participants, on-demand tadalafil 5 mg with dapoxetine 30 mg. The endpoints were change in intravaginal ejaculatory latency time and satisfaction scores, assessed at one, two and three months after treatment started.

The result is reported as a direction, not as a number. Highly statistically significant improvements were found in mean IELT and satisfaction scores at all three timepoints in all three groups (P < 0.001), and the post hoc analysis suggested the improvement was more pronounced in the combination group (P < 0.001).

What is absent matters as much as what is printed. Neither the mean latency at baseline nor the change in seconds appears in the abstract, for any arm. The effect size cannot be reconstructed from the text of this record. A reader who wants to know how many seconds the combination bought has to obtain the full paper, and even then, a single-clinic, three-arm, open-label design without a placebo arm is not the setting where a durable number would be expected to settle.

The four-arm trial

The 2021 paper in Urol Journal randomised 120 patients with premature ejaculation into four groups for one month of treatment: paroxetine alone, dapoxetine alone, paroxetine with tadalafil, and dapoxetine with tadalafil. The evaluated items were ejaculation duration, frequency of intercourse per week, and drug side effects, at two and four weeks. Mean ages were 32 ± 6.9, 32.4 ± 7.2, 31.6 ± 1.9 and 32.9 ± 7.7 years for the dapoxetine, paroxetine, paroxetine-tadalafil and dapoxetine-tadalafil groups.

Again the results are p-values. On ejaculatory latency at the four-week follow-up there was a significant difference between the dapoxetine group and the dapoxetine-tadalafil group (p = .029). At two weeks, significant differences ran between dapoxetine and dapoxetine- tadalafil (p = 0.043), paroxetine and paroxetine-tadalafil (p = 0.006), and paroxetine and dapoxetine-tadalafil (p = 0.004). At four weeks, significant differences in intercourse frequency ran between dapoxetine and paroxetine-tadalafil (p = 0.033), paroxetine and paroxetine-tadalafil (p = 0.043), paroxetine and dapoxetine-tadalafil (p = 0.02), and dapoxetine and dapoxetine-tadalafil (p = 0.016).

The authors’ own conclusion is that combination therapy was more effective in IELT than monotherapy, especially in younger patients, despite slightly more side effects. Note the words they chose: “slightly more side effects”, and “especially in younger patients”. Neither is a claim of a general advantage, and the four arms make it impossible to attribute the combination result to tadalafil’s own effect on latency rather than to additivity that this design cannot resolve.

Where the other six papers are

Four of them exist to detect these two substances in a formulation.

A 2020 spectrophotometric paper in Spectrochimica Acta built three validated methods for the simultaneous determination of dapoxetine hydrochloride and tadalafil: a first-derivative method reading peak amplitudes at 322.4 nm for dapoxetine and 230 nm for tadalafil with no interference between them, an area-under-curve method using 228-240 nm and 242-254 nm windows, and a ratio-subtraction method in which tadalafil was determined by dividing the mixture spectrum by the spectrum of a 15 µg/mL dapoxetine solution and dapoxetine by dividing by a 30 µg/mL tadalafil solution. A companion paper in the Journal of Chromatographic Science did the same pair by high-performance thin-layer chromatography, with concentration ranges of 0.1-1.6 and 0.2-2.5 µg/band and accuracies of 98.93% ± 0.62 and 99.26% ± 1.39, on silica gel plates with an ethanol-ethyl acetate mobile phase at 1:9 by volume read at 222 nm. A 2024 paper in the same spectroscopic journal applied functional principal component analysis and covariate design of experiments to reduce day-to-day and analyst-to-analyst variability in partial least squares models for the binary mixture.

The two that are about the product, not the patient

A 2021 paper in RSC Advances is the reason a catalogue page should care about this pair at all. The authors developed an HPLC-UV method and a UPLC-MS/MS confirmatory method to separate sildenafil, vardenafil and tadalafil together with their counterfeits — dapoxetine, paroxetine, citalopram, tramadol and yohimbine — and applied them to 50 commercial products including honey sachets and instant coffee marketed as aphrodisiacs. The full gradient run took 11 minutes on the HPLC-UV method and 6 minutes on the MS/MS method, read at 230 nm. The framing of the paper is that products sold outside a pharmacy channel are checked for substances that should not be in them, and that the check has to be a real chromatographic method rather than packaging.

The most recent record, 2026 in Pharmaceuticals, is a formulation paper rather than a clinical one. Tadalafil and dapoxetine were loaded into electrospun polyvinylpyrrolidone nanofibres for buccal delivery, from an 8% w/v PVP solution in ethanol containing 1.5% dapoxetine and 0.5% tadalafil, at 800 µL/h, 15 cm, a 0.55 mm needle and 8-10 kV. Fibres averaged 218 ± 50 nm, the film disintegrated within 4 ± 1 s, and in vitro release was burst followed by sustained: more than 45% for tadalafil and more than 50% for dapoxetine at 15 minutes, more than 60% and more than 78% at 30 minutes, and complete release of both by 180 minutes. Cytotoxicity was assessed on human dermal fibroblasts, with viability above 50% at 1.56-25 µg/mL tadalafil and 4.69-9.38 µg/mL dapoxetine after 24 and 48 hours.

The last record on this page is a toxicology method. A 2024 paper in the Journal of Chromatography B validated a method for 35 drugs of toxicological relevance in post-mortem human blood, among them sildenafil, tadalafil and dapoxetine. Limits of detection went as low as 0.01 ng/mL and limits of quantification as low as 0.04 ng/mL; bias stayed below 9% and relative standard deviation below 10%; extraction recovery exceeded 57.5% for all analytes except atenolol, and matrix effects stayed below 17% except for pindolol. The method was tested on two authentic human autopsy blood samples.

What the data do not show

They do not show an effect size. Both clinical abstracts report significance and direction; neither prints a mean ejaculatory latency in seconds for any arm, so no figure for the size of the benefit can be traced to a cited source here.

They do not show a placebo-controlled effect. The three-arm trial has no placebo arm and the four-arm trial’s comparator is another active drug.

They do not show anything about a specific commercial product. Nothing in either trial establishes what any named manufacturer or brand contains; the six analytical papers exist precisely because the composition of products sold outside a pharmacy channel cannot be assumed.

They do not show long-term outcomes. Both trials run one to three months, and neither reports anything beyond latency, satisfaction and side effects.

They do not show safety of unsupervised use. Both trials were run in specialist clinics with patients assessed by clinicians, which is the setting in which such questions are asked.

Where this sits on the shelf

The combination as supplied by the manufacturer: Sextreme Power XL (Tadalafil + Dapoxetine)

What we supply

The tadalafil and dapoxetine preparation above, as supplied by the manufacturer, tracked, from inside the EU.

Research use only. This page summarises published studies for research reference. It is not medical advice, not a treatment, and not a suggestion for human use. Nothing we supply is for human or veterinary use.