What is the role of Low-intensity shockwave therapy (LiST) in the treatment of erectile dysfunction (ED)?

Low-Intensity Shockwave Therapy for Erectile Dysfunction

Low-intensity shockwave therapy (LiSWT) is NOT recommended as first-line treatment for erectile dysfunction and should only be considered as an investigational option after PDE5 inhibitors have failed, as it is not included in established treatment guidelines and lacks FDA approval.

Guideline-Based Treatment Algorithm

First-Line Therapy: PDE5 Inhibitors

• Initiate treatment with oral PDE5 inhibitors (sildenafil, tadalafil, or vardenafil) as first-line therapy unless contraindicated 1, 2
• PDE5 inhibitors demonstrate 69% success rates versus 35% with placebo, with high-quality evidence supporting their use 1
• Perform an adequate trial of at least 5 separate occasions at maximum tolerated dose before declaring treatment failure 2
• Screen for absolute contraindications: patients taking nitrates (potentially fatal hypotension), unstable angina, uncontrolled hypertension, recent MI/stroke (within 2 weeks), severe heart failure (NYHA class II or greater), or high-risk arrhythmias 1, 2, 3

When PDE5 Inhibitors Fail

• Before switching therapies, evaluate: hormonal abnormalities (measure free testosterone if decreased libido present), medication interactions, proper dosing technique, adequacy of sexual stimulation, heavy alcohol use, and relationship issues 2
• Proceed to second-line therapies: intraurethral alprostadil suppositories, intracavernosal vasoactive drug injection, or vacuum constriction devices 2
• Penile prosthesis implantation remains the definitive third-line intervention for refractory ED 2

LiSWT: Current Evidence Status

Why LiSWT Is Not Guideline-Recommended

• LiSWT is conspicuously absent from all major clinical practice guidelines including the American College of Physicians (2009) 1 and American Urological Association (2005) 1 recommendations
• The most recent guideline summaries (2025) make no mention of shockwave therapy in their comprehensive treatment algorithms 2, 3, 4
• This absence is significant: guidelines from 2009 and 2005 could not have included LiSWT evidence, but updated 2025 summaries still omit it, suggesting insufficient evidence for guideline inclusion

Research Evidence: Promising But Preliminary

Efficacy Data:

• A 2022 double-blind RCT showed 79% of moderate ED patients achieved minimal clinically important difference (MCID) in IIEF-EF scores at 3 months versus 0% with sham treatment (risk difference 79%, p<0.001) 5
• A 2015 Indian population study demonstrated 78% of men achieved erections hard enough for penetration (EHS ≥3) at 1 month, sustained in 71% at 12 months, compared to 0% in placebo group 6
• A 2020 phase II trial showed 68% treatment success rate with statistically significant IIEF improvement from median 13 to 18 (p=0.011) 7

Durability Concerns:

• Long-term follow-up data from 2024 shows treatment effects peak at 12 months but decline significantly between 24-36 months 8
• Mean SHIM scores improved from baseline 10.8 to 15.6 at 12 months (p<0.001) and 15.0 at 24 months (p<0.001), but dropped to 12.2 at 36 months (p=0.31, no longer statistically significant) 8
• This suggests LiSWT may require retreatment after 2-3 years to maintain benefits 8

Protocol Variability:

• There is no standardized treatment protocol, with studies using 4-12 sessions, varying shock numbers (1,500-5,000 per session), and different energy levels (0.09-0.1 mJ/mm²) 7, 6, 8, 5, 9
• The most common protocol involves 1,500 shocks per session with 900 to penile shaft/base and 600 to proximal corpora/crura, at 0.09 mJ/mm² energy and 5 Hz frequency 9

Safety Profile:

• All studies report excellent safety with no serious adverse events 7, 6, 8, 5
• Minimal discomfort reported in <10% of patients, easily managed by device repositioning 7

Clinical Decision Framework

When to Consider LiSWT (Off-Guideline)

• Only after documented failure of maximum-dose PDE5 inhibitor trial (at least 5 attempts at highest tolerated dose) 2
• Patient refuses or cannot tolerate second-line invasive therapies (injections, intraurethral suppositories, vacuum devices) 2
• Patient specifically requests investigational therapy and understands lack of FDA approval and guideline support
• Mild to moderate vasculogenic ED (research populations show best response in this subset) 7, 6, 5

When NOT to Offer LiSWT

• As first-line therapy—this violates established guidelines 1, 2
• Before adequate PDE5 inhibitor trial 2
• In patients who have not been screened for cardiovascular risk factors 1, 2
• When patient expects permanent cure (evidence shows declining efficacy after 2 years) 8

Critical Pitfalls to Avoid

• Do not bypass PDE5 inhibitors: The evidence base for PDE5 inhibitors is vastly superior with high-quality evidence and strong guideline recommendations 1
• Do not promise permanent results: The 2024 long-term study clearly demonstrates waning efficacy between 24-36 months 8
• Do not ignore cardiovascular screening: ED is often the first manifestation of cardiovascular disease; all patients require risk stratification regardless of ED treatment chosen 1, 2, 3
• Do not overlook testosterone deficiency: Measure free testosterone in patients with decreased libido, as combination therapy may be more effective than monotherapy 2, 4
• Do not use LiSWT in patients who haven't tried lifestyle modifications: Counsel all ED patients on smoking cessation, weight loss, physical activity, and optimal management of diabetes/hypertension/dyslipidemia 2