How durable are penile length and curvature improvements from traction therapy at 12‑ and 24‑month follow‑up in randomized cohorts?
Executive summary
Randomized trials of modern penile traction therapy (PTT), especially RestoreX, show consistent, statistically and clinically meaningful improvements in penile length and curvature at 3 months and through short-term follow‑up (6–9 months) in intent‑to‑treat and as‑treated analyses [1] [2] [3]. However, randomized evidence that directly documents durability at 12 and 24 months is sparse: some nonrandomized and small randomized cohorts suggest maintained length gains with continued use and a plateau after cessation, but robust randomized 12–24 month durability data are largely lacking [4] [2] [5].
1. What randomized cohorts demonstrably achieved early gains, and how long were they followed?
The largest modern randomized, single‑blind RestoreX trial randomized men 3:1 and found significant improvements at 3 months for length (+1.5 cm vs 0 cm) and curvature (–11.7° vs +1.3°) with PTT versus controls (p<0.001 and p<0.01 respectively), and erectile function also improved [1] [3]. Those trial protocols included open‑label and follow‑up phases extending to 6–9 months, where control crossover to PTT showed length gains of roughly 1.7–2.0 cm and curvature improvements of about 18–20% on intent‑to‑treat analysis [2]. These randomized data establish reproducible short‑term benefit through the first 6–9 months [2] [1].
2. Twelve‑month outcomes: limited randomized data, mixed signals about persistence after stopping therapy
Some earlier prospective series and smaller cohorts reported reassessments at 12 months: a small cohort using older devices showed a nonsignificant curvature drop from 31° to 27° at 6 months and reported no further change in curvature or length in the subsequent 6 months after stopping device use, implying a plateau rather than progressive loss [4] [5]. That finding suggests length gains and modest curvature changes can persist through 12 months if the physiologic remodeling has consolidated, but the evidence comes from small, partially nonrandomized series and a post‑treatment “washout” assessment rather than large randomized long‑term follow‑up [4] [5]. Meta‑analytic aggregation finds an average curvature improvement of ~15.7° across studies, but follow‑up intervals vary and pooled durability at 12 months is not directly reported [6].
3. Twenty‑four‑month outcomes: evidence gap and indirect signals from related populations
There are essentially no large randomized PTT cohorts reporting 24‑month curvature and length outcomes in men with Peyronie’s disease; randomized trials typically report through 3–9 months with some open‑label extensions [2] [1]. Longitudinal penile length data after radical prostatectomy show that natural length recovery trends up to 24 months and beyond, but those findings do not isolate the effect of traction devices in randomized Peyronie’s cohorts [7]. Thus, claims of durable 24‑month curvature correction from randomized PTT trials cannot be substantiated with the current randomized literature provided.
4. What determines whether gains persist? — adherence, device design, and combined therapy
Across randomized and observational reports, adherence and device design strongly influence outcomes and likely durability: higher daily wear time and newer devices engineered for shorter, effective sessions (RestoreX: 30–90 minutes) correlated with larger and faster gains in length and curvature [1] [2]; conversely, older studies requiring 4–6 hours daily had poorer adherence and smaller or inconsistent curvature effects [8] [9]. Combination approaches—PTT plus intralesional enzymes or injections—produce greater curvature correction in multiple series, implying that PTT may consolidate enzymatic remodeling and thus enhance medium‑term durability [10] [8] [11].
5. Bottom line and research gaps
Randomized trials convincingly show meaningful improvements in penile length and curvature through short‑term follow‑up (3–9 months) with modern PTT devices [1] [2], and several small cohorts report persistence to 12 months or a plateau after stopping use [4] [5]. However, there is an absence of large, randomized 12‑ and 24‑month durability data specific to Peyronie’s disease, so any assertion of durable 24‑month curvature correction from randomized cohorts exceeds what current published randomized evidence supports [2] [1] [7]. Future randomized trials must include prespecified 12‑ and 24‑month endpoints and report outcomes stratified by adherence and concomitant therapies to settle whether early gains become durable without ongoing device use [6] [10].