The outcomes of non-surgical and surgical penile augmentation procedures: a systematic review and meta-analysis

Despite the growing popularity of penile augmentation procedures, evidence on benefits and risks across techniques remains limited. This systematic review and meta-analysis aimed to evaluate changes in penile dimensions and adverse events following penile augmentation procedures. Five databases (PubMed, PsycINFO, CINAHL, Web of Science, and Embase) were searched from inception to 16 September 2025, following PRISMA and MOOSE reporting standards. Random-effects meta-analyses were performed using restricted maximum likelihood estimation. Pooled mean differences are reported with 95% confidence intervals and 95% prediction intervals. Thirty studies comprising 2554 participants were included. Given extreme between-study heterogeneity, inference for girth was based primarily on technique-specific estimates. Penile girth increased after non-autologous injectable fillers by a pooled mean of 1.88 cm (95% CI 1.53-2.23; 95% prediction interval 0.27-3.49; k = 18; I² = 100%) and after autologous surgical grafts by a pooled mean of 1.99 cm (95% CI 0.90-3.08; 95% prediction interval -1.73-5.70; k = 5; I² = 99.2%). An exploratory overall girth estimate pooling all techniques was 1.86 cm (95% CI 1.55-2.17; 95% prediction interval 0.13-3.59; k = 29; I² = 100%). Flaccid penile length increased by a pooled mean of 2.20 cm (95% CI 1.79-2.61; 95% prediction interval 0.93-3.46; k = 7; I² = 81.7%). Erect penile length increased by a pooled mean of 1.36 cm (95% CI 0.18-2.53; 95% prediction interval -2.58-5.30; k = 4; I² = 92.3%). Prediction intervals, not pooled means, should guide expectations for a future patient. Magnitude and safety differ by modality. Prospective studies with standardised measurement, validated patient-reported outcomes, and consistent complication grading are required.