Penile BOTOX injections improve blood flow and other outcomes in men with moderate to severe erectile dysfunction

Kirk Taylor, HIV i-Base

A double-blind randomised controlled trial evaluated BOTOX injections as therapeutic intervention for men with moderate to severe erectile dysfunction (ED). [1]

BOTOX injections improved penile blood flow and participants reported improved ability to maintain erections during penetrative sex. High dose BOTOX (100 units) was most durable with effects observed out to 24 weeks. Longer follow-up periods are required to establish minimum treatment intervals.

Botox injections helped 40% of participants restart sexual activities but others continued to report being unable to complete intercourse.

Erectile dysfunction (ED) is a global problem and is associated with co-morbidities, such as cardiovascular disease, neuropsychological disorders, HIV and depression. The efficacy of pharmaceutical interventions (e.g. PDE-5 inhibitors) are short-lived and there is demand for alternatives.

BOTOX is widely used in cosmetic and medical procedures and can improve blood flow, which would be of benefit to people with ED.

Males (n=176) who had not responded to pharmaceutical interventions were enrolled onto the study, median age was 55 years (IQR: 49 to 64) and median time since diagnosis was 6 months (IQR: 6 to 12 months). Co-morbidities were common and were evenly distributed between groups.

Participants were randomised to receive placebo (n=55), 50 Units BOTOX (n=59) or 100 Units BOTOX (n=62) injections at four sites at the base of the penis.

Median SHIM (sexual health inventory for men) scores at baseline were 8 (IQR: 7 to 9) indicative of moderate to severe ED. BOTOX injections significantly improved SHIM scores at weeks 2 and 12 (p>0.05). Week 24 show a decrease of SHIM scores from 13 (IQR: 12 to 15) to 8 (8 to 10) in the 50 unit BOTOX group. The higher dose group (100 units) maintained SHIM scores across the study period.

BOTOX treatment improved blood flow and modestly increased stretched penile length with no change to penile girth.

Some adverse events (4%) were reported as follows: penile pain that was managed with analgesics (n=1), injection site hematoma (n=1) and prolonged erection during doppler flow assessment (n=4). No systemic adverse events were reported.


This study is included in HTB as a potential option for people who have not responded to other available treatment. The data should be interpreted cautious until confirmed in other studies.

A linked editorial congratulates the authors on their study, but also raises questions about the relatively short follow-up period and failure to stratify participants by vascular complications.

Further information is also required to determine the long-term impact of BOTOX therapy and which people with ED are most likely to benefit. [2]

Further information on sexual health and well-being is included in the recently updated i-Base guide to HIV and quality of life. [3]


  1. El-Shaer W et al. Intra-cavernous injection of BOTOX (50 and 100 Units) for treatment of vasculogenic erectile dysfunction: randomized controlled trial. Andrology. (30 march 2021).  
  2. Barros RB. Editorial Comment: Intra-cavernous injection of BOTOX (50 and 100 Units) for treatment of vasculogenic erectile dysfunction: Randomized controlled trial. Int Braz J Urol. (11 November 2022).
  3. Sexual health and well-being. (01 November 2021).


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