“Injaculation”: Everything You Never Wanted to Know

Andrew Siegel MD   12/31/2022

Ejaculation is important to many men and their partners. Issues with ejaculation can be bothersome, distressing, and sometimes even relationship-threatening. It is undesirable to arrive at the moment of ejaculation too quickly, too delayed, or not at all.  Clearly, aspects of ejaculation—its rapidity, occurrence, intensity, and volume of semen released—are strongly related to the male’s perception of sexual satisfaction and are likely related to the partner’s as well.

The word “ejaculation” derives from ex, meaning out and jaculari, meaning to throw, shoot, hurl, cast.  The first time I dictated “ejaculation” using Dragon Dictate software, the written response was “jack-elation,” which I thought was a clever interpretation emphasizing the physical (“jack”) and the emotional (“elation”).

Despite what you may think, ejaculation was not designed with man’s pleasure in mind, but as a means of facilitating the placement of the male’s DNA into the female’s reproductive tract for purposes of perpetuation of the species. The pleasure associated with the sexual act and ejaculation is nature’s clever bait and switch to provide the “carrot” that keeps the reproductive process running.

95+% of the ejaculate volume is a cocktail of genital secretions that provides nourishment, support, and chemical safekeeping for sperm. About 70% is derived from the seminal vesicles, which secrete a viscous fluid, and 25% is from the prostate, which produces a milky-white fluid. A negligible amount is from the bulbourethral glands, which release a clear viscous fluid that has a lubrication function. Less than 5% of the ejaculate volume is sperm. The average ejaculate volume is 2-5 milliliters (one teaspoon is the equivalent of 5 milliliters).

After a threshold of sexual stimulation is surpassed, a “point of no return” is achieved, in which ejaculation becomes inevitable. At this point emission releases pooled reproductive secretions (from the prostate gland, seminal vesicles, epididymis, and vas deferens via the ejaculatory duct) into the prostatic urethra. At this time, the bladder neck contracts and closes. Shortly thereafter, in the process of expulsion, these secretions are propelled out the urethra via rhythmic contractions of the pelvic floor muscles. Under normal circumstances the bladder neck sphincter contracts prior to ejaculation, this closure resulting in the antegrade (forward) release of semen out the urethra, the path of least resistance.  However, if the bladder neck is not completely sealed closed, the ejaculation will reverse flow with the seminal discharge entering the urinary bladder, a phenomenon called retrograde ejaculation.   

Ejaculation quality and quantity may be compromised due to a variety of circumstances including aging, medical illnesses, medications, and surgery.   Medications and surgery that are used to treat lower urinary tract symptoms from prostate enlargement often profoundly affect ejaculation. A relatively common impairment of ejaculation is retrograde ejaculation (backwards ejaculation, a.k.a. internal ejaculation, a.k.a “in-jaculation,” a.k.a. dry orgasm) that results in little to no volume of semen expelled from the urethra. Under this circumstance, the semen is directed into the urinary bladder, which is the path of least resistance, resulting from failure of the bladder neck sphincter to close and seal properly. The semen is eliminated from the body at the time of urination and has no ill health consequences.


Retrograde Ejaculation (Injaculation)
Wumingbai, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0&gt;, via Wikimedia Commons

Neurological problems that cause autonomic nervous system dysfunction — including diabetes, multiple sclerosis, and spinal cord injury — are common causes of injaculation. 

There are five alpha-blocker medications commonly used to treat lower urinary tract symptoms caused by prostate enlargement. Many of these such as tamsulosin (Flomax) and silodosin (Rapaflo) will cause injaculation because of their mechanism of action inducing relaxation of the prostate and bladder neck smooth muscle.  Some antidepressant and antipsychotic medications may also induce injaculation.

Surgical procedures to alleviate prostate obstruction including Greenlight laser photovaporization (PVP) and transurethral resection of the prostate (TURP) commonly cause injaculation because of removal of bladder neck tissue and obstructing apical prostate tissue near the striated sphincter (voluntary sphincter) mechanism.  Retroperitoneal surgery including lymph node dissection for testes cancer can potentially damage nerve pathways giving rise to retrograde ejaculation.

Retrograde ejaculation is harmless to the body and rarely needs to be treated.  Sympathomimetic medications increase the tone and contractility of the bladder neck and when taken prior to sexual intercourse can occasionally be effective at improving or eliminating injaculation.  However, there are numerous potential side effects with this class of medication. Bulking agents to try to bulk up and constrict the bladder neck are another possible management option. If fertility is an issue, post-ejaculation urine can be collected, centrifuged, and the semen used for intrauterine insemination.  

As mentioned above, the alpha-blocker class of medication is commonly prescribed to treat symptoms caused by prostate enlargement and often incur the side effect of injaculation. However, some members of this medication class are much less prone to cause injaculation than others (e.g., Uroxatral {Alfuzosin}), so there are alternatives that can spare ejaculation.   Some patients stop taking their alpha-blockers for a day or two prior to sexual activity to restore antegrade ejaculation and feel that the resulting impairment with urinary flow while off the alpha-blockers is worth the tradeoff of restored ejaculation.

Wishing you the best of health,

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Dr. Andrew Siegel is a physician and urological surgeon who is board-certified in urology as well as in female pelvic medicine and reconstructive surgery.  He is an Assistant Clinical Professor of Surgery at the Rutgers-New Jersey Medical School and is a Castle Connolly Top Doctor New York Metro AreaInside Jersey Top Doctor and Inside Jersey Top Doctor for Women’s Health. His mission is to “bridge the gap” between the public and the medical community. He is a urologist at New Jersey Urology, one of the largest urology practices in the United States.  He is the co-founder of PelvicRx and Private Gym.  His latest book is Prostate Cancer 20/20: A Practical Guide to Understanding Management Options for Patients and Their Families. 

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Video trailer for Prostate Cancer 20/20

Preview of Prostate Cancer 20/20

Andrew Siegel MD Amazon author page

PROSTATE CANCER 20/20 is now available at Audible, iTunes and Amazon as an audiobook read by the author (just over 6 hours). 

Dr. Siegel’s other books:

THE KEGEL FIX: Recharging Female Pelvic, Sexual, and Urinary Health


MALE PELVIC FITNESS: Optimizing Sexual and Urinary Health

PROMISCUOUS EATING— Understanding and Ending Our Self-Destructive Relationship with Food

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One Response to ““Injaculation”: Everything You Never Wanted to Know”

  1. Carl J Manni Says:


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