What randomized controlled trials exist on penile traction devices and what do their long‑term follow‑ups show?
Executive summary
Randomized controlled trials of penile traction devices (PTDs) are limited but growing: the most-cited RCTs evaluate the RestoreX device in men with Peyronie’s disease (n=110, randomized 3:1) and a separate randomized trial of RestoreX after prostatectomy (n=82), and follow-up data generally extend to 6–9 months with consistent short‑term gains in penile length, curvature, and some measures of erectile function (EF) but little evidence beyond one year [1] [2] [3] [4]. Systematic reviews and narrative syntheses conclude PTDs are promising and safe for short‑to‑medium term anatomical improvements, while calling for larger, longer RCTs and attention to patient-centered outcomes [5] [6] [4].
1. The randomized evidence: RestoreX in Peyronie’s disease and the prostatectomy trial
A single‑blinded RCT of the RestoreX device randomized 110 men with Peyronie’s disease 3:1 to daily traction (30–90 minutes) versus no therapy for 3 months and reported statistically significant and clinically meaningful improvements in penile curvature, length (+1.5 cm vs 0 at 3 months), and EF in men with baseline erectile dysfunction [1] [7]. A separate randomized, single‑center trial in men after radical prostatectomy (n≈82 randomized with 6‑month data on a subset) compared two daily PTT schedules to controls and found better preservation/increase of penile length (+1.6 vs +0.3 cm at 6 months) and small but statistically significant benefits in IIEF erectile function and intercourse satisfaction at 6 months [2] [8].
2. What follow‑ups show: durability to 6–9 months, sparse beyond
Open‑label and follow‑up phases of the Peyronie’s RestoreX trial extended outcomes to 6 and 9 months (mean device use ~31 minutes/day) and reported maintained improvements in length (roughly 1.7–2.0 cm for those switching from control to PTT) and curvature (approx. 18–20% improvement) with no significant long‑term adverse events in that window [3] [9]. Meta‑analyses covering multiple PTD studies confirm follow‑up durations clustered between 3 and 9 months (mean ~6.75 months) and therefore underscore that durable evidence beyond this period is largely absent from the RCT literature [4] [5].
3. Safety profile and patient experience in trials
Across RCTs and follow‑up reporting, PTDs were generally well tolerated: most adverse events were transient local effects such as erythema or mild discomfort that resolved quickly, and no major device‑related harms were reported in the trial cohorts through the 6–9 month follow‑up [1] [3]. Device adherence and tolerability were highlighted as design goals for RestoreX (shorter daily wear times compared with older devices), which likely improved uptake in trial settings [7] [10].
4. Synthesis and dissent: efficacy signals but unanswered long‑term questions
Systematic reviews and narrative reviews synthesize three RCTs among the available trials and find PTDs can reduce curvature and increase length in the short to mid term, but they uniformly call for more high‑quality RCTs with longer follow‑up, better reporting of psychological/partner outcomes, and exploration of optimal dosing and combinations with medical therapies [4] [6] [5]. Some prior rehabilitation trials in other post‑surgical contexts have failed to show spontaneous EF recovery, underscoring that results may vary by population and that earlier negative trials temper enthusiasm for broad claims [11].
5. Conflicts, funding, and editorial context to weigh
Trials of RestoreX were conducted with device provision from PathRight Medical (devices supplied at no cost) and internal institutional support noted in follow‑up reporting, which should be disclosed when interpreting enthusiasm for a proprietary device [9]. Meta‑analyses and reviews repeatedly flag heterogeneity in study design, short follow‑up windows (3–9 months), and small sample sizes as reasons to temper claims of durable benefit [4] [6] [5].
6. Bottom line for clinicians and researchers
Randomized data show consistent short‑term benefits of PTDs—especially the RestoreX trials—in penile length and curvature and modest EF improvements in select groups through 6–9 months, with good tolerability; however, the RCT literature lacks longer‑term (≥12 months) randomized follow‑up and larger multicenter confirmatory trials, so durability, optimal protocols, and patient‑centered impact remain unresolved [1] [2] [3] [4] [6].