What the Cochrane Review Says and How APU Integrates the Evidence
Erectile dysfunction affects millions of men worldwide. For decades, oral medications known as PDE5 inhibitors – sildenafil (Viagra), tadalafil (Cialis), and others have been the standard of care. These drugs work well for most men. However, not everyone responds. Some men cannot tolerate the side effects. Others have medical conditions or take medications that interact with PDE5 inhibitors. And some men simply prefer a non-pharmacological approach.
In recent years, a new treatment has gained attention: low-intensity shockwave therapy, or LiSWT. The concept is straightforward. Sound waves of low energy are applied to the penis. The goal is to improve blood flow by stimulating the growth of new blood vessels (angiogenesis) and repairing damaged endothelium – the inner lining of blood vessels. The treatment is non-invasive, painless, and does not require medication or anesthesia. A typical session lasts 15 to 20 minutes and is repeated several times over a few weeks.
But does LiSWT actually work? Until recently, the evidence was mixed. Many small studies reported positive results, but they had serious methodological flaws. Patients and clinicians needed a reliable, unbiased summary of the best available evidence.
What the Cochrane Review Found
In 2025, the Cochrane Collaboration widely regarded as the gold standard for evidence synthesis published a comprehensive systematic review on LiSWT for erectile dysfunction. The full text is available here:
Cochrane systematic review (2025) on low-intensity shockwave therapy for erectile dysfunction
This review is important because Cochrane applies the most rigorous methods available. The authors searched multiple databases, included only randomized controlled trials (the strongest study design for treatment effects), and assessed the certainty of evidence using the GRADE system.
The Cochrane review included 21 randomized controlled trials with a total of 1,357 men. These men were between 39 and 65 years old and had erectile dysfunction for an average of 3 to 68 months. Most had mild or mild-to-moderate ED based on the International Index of Erectile Function – Erectile Function domain (IIEF-EF), a standardized questionnaire where scores range from 6 (severe dysfunction) to 30 (normal function). Baseline scores in the included studies ranged from 7 to 20.
The review compared LiSWT to sham treatment a device that looked and sounded real but delivered no actual shockwaves. All active treatment periods lasted three months or less. The researchers measured several outcomes: erectile function, treatment discontinuation, adverse events, penile rigidity, patient and partner satisfaction, and sexual quality of life.
Key Findings
Erectile function. In the short term (three months or less), LiSWT improved IIEF-EF scores by an average of 3.89 points compared to sham (95% confidence interval 2.89 to 4.89). The minimal clinically important difference (MCID) for this scale is 4 points. This means the average improvement was just below the threshold that men typically notice. In the long term (more than three months), the improvement was 5.25 points (95% CI 2.47 to 8.04), which exceeds the MCID. However, the certainty of this evidence was rated LOW for both time points.
Penile rigidity. Using the Erectile Hardness Score (EHS, scale 1 to 4, with 4 being normal), LiSWT improved rigidity by 1.06 points in the short term and 0.91 points in the long term. The MCID for EHS is 1 point. So the short-term effect just reaches clinical significance, while the long-term effect falls slightly below it. Again, the certainty of evidence was LOW.
Treatment discontinuation and adverse events. LiSWT had little to no effect on either outcome. Discontinuation rates were similar between LiSWT and sham (risk ratio 0.77, 95% CI 0.47 to 1.27). Adverse events were extremely rare in both groups (risk difference 0.00). This is reassuring: LiSWT appears very safe.
Missing outcomes. The review found no evidence on patient or partner satisfaction, and no evidence on sexual quality of life. These are important gaps. A treatment that improves questionnaire scores but does not make patients happier or improve their sex life may not be worth the time and cost.
Why the Certainty of Evidence Is Low
The Cochrane review rated the certainty of evidence as LOW for every single outcome. This does not mean LiSWT definitely does not work. It means we cannot be confident that the observed effects are real or clinically important. There are three main reasons for this low certainty.
List 1: Three Reasons for Low Certainty of Evidence
- Study limitations (risk of bias). Many of the 21 trials had poor methodological quality. Some did not properly blind patients or outcome assessors. Others had high dropout rates or did not report all outcomes. A few were published only as abstracts with incomplete methods.
- Inconsistency (heterogeneity). The results varied widely from study to study. For long-term erectile function, the statistical heterogeneity (I²) was 87% – extremely high. This means the studies disagree with each other, making it hard to draw a firm conclusion.
- Imprecision (wide confidence intervals). Many outcomes had confidence intervals that included both no effect and a large effect. For example, the long-term improvement in IIEF-EF ranged from 2.47 to 8.04 points. This uncertainty reduces confidence.
In addition, 9 of the 21 studies were funded by companies that manufacture shockwave devices. Industry funding does not automatically invalidate results, but it is a known risk factor for bias. Five studies reported no industry funding, and the remainder did not disclose funding sources.
Understanding the Numbers: Key Results from Cochrane
To make the findings clearer, here is a summary of the main results from the Cochrane review. The table below shows the effect of LiSWT compared to sham treatment for each outcome.
| Outcome | Time point | Effect (95% CI) | Certainty | Clinically important? |
| IIEF-EF (6 to 30 points) | Short-term (≤3 months) | MD +3.89 (2.89 to 4.89) | LOW | No (below MCID of 4) |
| IIEF-EF (6 to 30 points) | Long-term (>3 months) | MD +5.25 (2.47 to 8.04) | LOW | Yes (exceeds MCID) |
| Erectile Hardness Score (1 to 4) | Short-term | MD +1.06 (0.83 to 1.28) | LOW | Yes (meets MCID of 1) |
| Erectile Hardness Score (1 to 4) | Long-term | MD +0.91 (0.36 to 1.46) | LOW | No (below MCID) |
| Treatment discontinuation | Short-term | RR 0.77 (0.47 to 1.27) | LOW | No (little to no effect) |
| Adverse events | Short-term | RD 0.00 (-0.01 to 0.02) | LOW | No (little to no effect) |
| Adverse events | Long-term | RD 0.00 (-0.02 to 0.02) | LOW | No (little to no effect) |
| Patient/partner satisfaction | Any | No evidence | – | Cannot assess |
| Sexual quality of life | Any | No evidence | – | Cannot assess |
MD = mean difference; RR = risk ratio; RD = risk difference; CI = confidence interval; MCID = minimal clinically important difference
What does this table tell us? First, LiSWT may improve erectile function and penile rigidity, but the effects are small and the certainty of evidence is low. Second, the treatment is very safe – adverse events are no more common than with sham. Third, we have no information on whether patients or their partners are actually satisfied with the results, nor on whether quality of sexual life improves.
What Cochrane Did Not Find (Important Gaps)
The absence of evidence on certain outcomes is just as important as the presence of evidence on others. The Cochrane review highlighted several gaps that should give both clinicians and patients pause.
Key Gaps in the Evidence
- No data on patient or partner satisfaction. This is striking. A treatment could improve IIEF-EF scores by 5 points, but if men are not happier with their erections or their partners are not satisfied, what has been achieved?
- No data on sexual quality of life. Erectile function is only one aspect of sexual health. Quality of life matters more. We do not know if LiSWT improves it.
- Short treatment duration only. All studies applied LiSWT for three months or less. There is no evidence on what happens after a full course ends. Do the effects last? Does maintenance therapy help? Unknown.
- Industry funding. Nine of 21 studies were funded by device manufacturers. While this does not automatically mean the results are false, it is a well-documented source of bias in medical research.
How APU Uses LiSWT in Clinical Practice
Based on this Cochrane review, we at Adult & Pediatric Urology (APUMN) have developed a practical approach to LiSWT. We do not present it as a miracle cure. We present it honestly, with all its limitations.
First, LiSWT is not first-line therapy. For most men with erectile dysfunction, the first step is lifestyle modification: weight loss, exercise, smoking cessation, and reduction of alcohol intake. The second step is PDE5 inhibitors such as sildenafil or tadalafil. These drugs have high-quality evidence supporting their use, with large trials and decades of clinical experience. LiSWT comes later.
Second, LiSWT is appropriate for specific patient groups. Based on the Cochrane evidence and our clinical experience, we consider LiSWT for three categories of men.
Three Clinical Scenarios Where APU Considers LiSWT
- PDE5 non-responders. Men who have tried oral medications at adequate doses and still cannot achieve satisfactory erections. This group has few good options. LiSWT offers a non-invasive alternative before moving to injections or implants.
- Men who cannot tolerate PDE5 inhibitors. Some men experience severe headaches, flushing, nasal congestion, or visual disturbances. Others take nitrates for heart disease, which makes PDE5 inhibitors dangerous. For these men, LiSWT is a safe option.
- Men who prefer a non-pharmacological, device-based treatment. Some patients simply do not want to take a pill before every sexual encounter. They prefer a treatment that addresses the underlying vascular problem rather than temporarily managing symptoms. LiSWT appeals to this group, even if the evidence is less robust.
Clinical Approach at APU
Third, we set realistic expectations. We explain to patients that the Cochrane review found low-certainty evidence for small effects. The average improvement in IIEF-EF was 3.89 points in the short term just below what most men would notice. Some men will do better. Some will do worse. Some will see no improvement at all. We do not guarantee results.
Fourth, we follow a standard protocol. Our typical LiSWT course consists of six to twelve sessions, delivered two to three times per week. Each session lasts about 20 minutes. No anesthesia is needed. The device is applied to several areas of the penis – the shaft, the crura (where the penis attaches to the pelvic bone), and sometimes the perineum. The energy level is low, typically 0.05 to 0.20 mJ/mm², well below the threshold that causes tissue damage. Patients feel a gentle tapping sensation but no pain.
Fifth, we reassess after the full course. We repeat the IIEF-EF questionnaire and ask about real-world sexual function. If a patient has improved and is satisfied, we discuss maintenance – typically a repeat course every six to twelve months, although evidence for this is lacking. If a patient has not improved, we do not repeat LiSWT. We move on to other options: vacuum erection devices, intracavernosal injections (alprostadil), or penile implant surgery.
Safety and Side Effects
The Cochrane review found no difference in adverse events between LiSWT and sham. In our own experience at APU, we have seen very few side effects. Some men report mild discomfort during the treatment. A few have noticed temporary redness or bruising at the application site. These resolve within hours to days. There have been no serious adverse events no bleeding, no infection, no pain requiring medication, no worsening of erectile function.
This safety profile is important. Even if the benefits are small, the risk is near zero. For men who have exhausted other options or who cannot use PDE5 inhibitors, LiSWT offers a reasonable trial of therapy with little downside.
Comparison to Other ED Treatments
To put LiSWT in context, it is helpful to compare it to other treatments for erectile dysfunction.
PDE5 inhibitors (sildenafil, tadalafil, vardenafil, avanafil) have strong evidence from large randomized trials. They work for about 70-80% of men. The effect is large and reliable. Side effects are common but usually mild. The main limitations are the need to take a pill before sex (except daily tadalafil) and contraindications with nitrates.
Vacuum erection devices are effective but cumbersome. Many men find them awkward or unnatural. They have a high dropout rate.
Intracavernosal injections (alprostadil) are very effective – about 85% of men achieve an erection adequate for intercourse. However, injections are invasive. Some men fear needles. Side effects include pain, prolonged erection (priapism), and fibrosis of the penis with long-term use.
Penile implants are the most invasive but also the most reliable. Satisfaction rates exceed 90%. However, surgery carries risks of infection, mechanical failure, and erosion. Implants are reserved for men who have failed all other treatments.
LiSWT occupies a middle ground. It is less effective than PDE5 inhibitors or injections, but it is non-invasive and painless. It does not require medication before sex. It may address the underlying vascular pathology rather than just symptoms. For the right patient, these advantages outweigh the modest and uncertain benefits.
The Honest Conversation with Patients
At APUMN, we believe in informed consent based on the best available evidence. When a man asks about LiSWT, we have an honest conversation. We tell him the following.
The Cochrane review, which is the most rigorous summary of the evidence, found that LiSWT may improve erectile function but the improvement is small and the certainty of the evidence is low. Most men will not notice a dramatic change. Some will notice none at all. The treatment is very safe, with almost no side effects. There is no evidence on whether patients or their partners are actually satisfied with the results. The studies were mostly small, poorly designed, and often funded by device manufacturers.
We also tell him what we do not know. We do not know how long the effects last. We do not know whether repeating the course helps. We do not know if LiSWT works for severe ED or for men with nerve damage after prostate surgery (because those men were excluded from the trials).
And then we ask: given these uncertainties, would you like to try it? Some men say yes. Some say no. Both are reasonable answers.
Conclusion
The Cochrane systematic review of low-intensity shockwave therapy for erectile dysfunction is a landmark synthesis. It tells us that LiSWT may have small effects on erectile function and penile rigidity, but the certainty of the evidence is low. It tells us that the treatment is very safe. It also tells us that we lack evidence on outcomes that matter most to patients: satisfaction and quality of life.
At APUMN, we use LiSWT as a second-line or third-line option. We reserve it for men who have failed PDE5 inhibitors, cannot tolerate them, or prefer a non-pharmacological approach. We set realistic expectations. We do not promise miracles. And we continue to monitor the evidence as new trials are published.
For now, LiSWT is not a breakthrough. It is not a cure. But it is a reasonable option for selected patients especially those with few other choices. The Cochrane review provides the clarity needed to have an honest conversation. And at APU, that is exactly what we do.
Author
Gregory S. Parries, M.D., PhD
