How Do Women Squirt? The Science Explained

Squirting during sexual arousal involves the rapid, involuntary release of fluid from the bladder through the urethra, triggered by intense genital stimulation. Ultrasound imaging has confirmed that the bladder fills noticeably during arousal and empties at the moment of squirting, and biochemical testing shows the fluid is primarily a dilute form of urine mixed with small amounts of prostatic secretions from the Skene’s glands. The phenomenon is distinct from what researchers call “female ejaculation,” a smaller, thicker secretion from those same glands, though the two are often conflated in popular conversation.

Squirting and Female Ejaculation Are Not the Same Thing

One of the biggest sources of confusion is that “squirting” and “female ejaculation” get used interchangeably in everyday language, but researchers treat them as two separate events with different sources and different fluid compositions. Squirting refers to the expulsion of a relatively large volume of clear fluid through the urethra during orgasm or intense arousal. Female ejaculation, by contrast, involves only a few milliliters of thick, whitish fluid secreted by the Skene’s glands, sometimes called the female prostate. A narrative review in the International Urogynecology Journal defined squirting as the transurethral expulsion of tens of milliliters of a dilute, urine-like fluid containing urea, creatinine, and uric acid, while female ejaculation was defined as a small secretion containing prostate-specific antigen (PSA) with minimal urinary markers.¹

A recent systematic review and meta-analysis quantified these differences precisely. Female ejaculate was consistently described as small-volume fluid, typically one to five milliliters, with elevated PSA and almost no urinary solutes. Squirting fluid, on the other hand, had a median volume of about 60 milliliters (with a range as wide as 15 to 900 milliliters), and its urea and creatinine concentrations were comparable to urine.² Both events can happen during the same sexual experience, which partly explains why they get lumped together. But they come from different anatomical sources: squirting comes from the bladder, and female ejaculate comes from the paraurethral glands.

What Ultrasound Studies Reveal About the Mechanism

The most direct evidence for how squirting works comes from a 2015 study that used pelvic ultrasound to monitor the bladders of seven women who reported regular squirting. Each woman’s bladder was scanned at three points: before sexual stimulation (empty), during arousal just before squirting, and immediately after. The scans showed a clear pattern. The bladder, which was confirmed empty at the start, filled noticeably during sexual arousal. Then, at the moment of squirting, it emptied again.³ This rapid bladder filling during arousal, followed by sudden release, is the core mechanism researchers point to.

The researchers concluded that squirting is essentially an involuntary emission of urine during sexual activity, though with a marginal contribution from prostatic secretions. That finding has been reinforced by dye studies where indigo-carmine, a dye that collects in urine, was introduced into the bladder beforehand. When squirting occurred, the expelled fluid contained the dye, confirming it came through the urethra from the bladder.²

What triggers the bladder to fill so quickly during arousal is less well understood. Increased blood flow to the pelvic region during sexual excitement almost certainly plays a role, as the kidneys continue producing urine and pelvic engorgement may accelerate the rate at which urine accumulates. The release itself appears to be tied to involuntary relaxation or contraction patterns in the pelvic floor. Research on the neural pathways involved in orgasm has identified a brainstem region that controls pelvic floor contractions during climax, and this same circuitry likely overlaps with the pathways that govern bladder voiding.⁴

What the Fluid Actually Contains

Biochemical analysis of squirting fluid reveals it to be a modified version of urine, not pure urine in the everyday sense. In the 2015 ultrasound study, researchers compared samples taken before stimulation (a baseline urine sample), the squirted fluid itself, and a urine sample collected after squirting. Urea, creatinine, and uric acid concentrations were comparable across all three, indicating a shared origin in the kidneys and bladder.³ But in five of the seven women, the squirted fluid also contained PSA, a protein produced by the Skene’s glands. The urine samples collected before and after did not contain PSA, meaning the prostatic contribution was unique to the moment of squirting.

A detailed single-case study took this further by analyzing both the large-volume squirted fluid and the small-volume ejaculate separately. The squirted fluid had the chemical profile of diluted urine, while the ejaculatory fluid had very high PSA concentrations, comparable to components found in male seminal fluid.⁵ So the fluid picture is a mix: squirting is mostly bladder-derived, but it picks up prostatic secretions as it passes through the urethra. How much of those secretions are present varies from person to person and even from one occasion to the next.

The presence of PSA in squirting fluid also suggests a possible protective role. PSA has antimicrobial properties, and research has proposed that the fluid may help flush bacteria from the urethra during or after intercourse.⁶

The Anatomy Behind It

The Skene’s glands, also called the paraurethral glands or the female prostate, are small structures embedded in the tissue surrounding the urethra near its opening. They are the developmental equivalent of the male prostate and share its basic tissue structure: clusters of glandular tissue surrounded by connective tissue and smooth muscle fibers.⁷ Like the male prostate, these glands produce PSA and drain their secretions into the urethra through small ducts.

Here is where anatomy creates individual variation. The size and development of the Skene’s glands differ considerably between women. Some women have well-developed glandular tissue; others have very little. This variation almost certainly affects the chemical makeup of the expelled fluid and may partly explain why some women produce noticeably more prostatic secretion mixed in with the squirted fluid than others. The glands are also hormone-sensitive. Animal research on gerbils has shown that estrogen exposure can cause significant changes in Skene’s gland tissue, including increased cell proliferation and upregulation of hormone receptors.⁸ Whether hormonal contraceptives or natural hormonal shifts across the menstrual cycle influence squirting in humans is an open question, but the biological plausibility is there.

The area around the Skene’s glands and the anterior vaginal wall is also the region popularly known as the G-spot. Stimulation of this area puts pressure on both the glands and the underlying urethra, and it is the type of stimulation most commonly associated with squirting in anecdotal and survey-based reports.

How Common Is Squirting

Survey data suggests squirting is more common than many people assume. A 2023 study using a U.S. probability sample found that about 40 percent of adult women had squirted at least once in their lifetime, with a median frequency among those who had experienced it of three to five times.⁹ A Swedish cross-sectional study found even higher numbers: 58 percent of women reported personal experience with ejaculation or squirting. Among women who had never experienced it, about 29 percent said they wished they could, while roughly a third said “maybe.”¹⁰

The Swedish study also found that women with non-heterosexual orientations were more likely to have experienced squirting than heterosexual women, at about 63 percent versus 52 percent.¹⁰ The reasons for that gap are not settled, but one plausible factor is that sexual encounters between women may involve more focused clitoral and anterior vaginal wall stimulation, the kind of stimulation most associated with the response. Cultural comfort with exploring one’s body and a broader definition of what “counts” as sex could also play a role.

These numbers should be interpreted with some caution. Both studies relied on self-report, and the line between squirting, increased vaginal lubrication, and coital incontinence can be blurry in the moment. Still, the data make clear that this is not an exotic rarity. It is a relatively common sexual response.

Squirting Is Not the Same as Urinary Incontinence

Because the fluid comes from the bladder, a natural question is whether squirting is just urinary incontinence by another name. Clinicians and researchers draw a firm line between the two. Coital incontinence is an involuntary urine leak during sex that typically bothers the person experiencing it and is associated with diagnosable pelvic floor dysfunction, such as stress urinary incontinence or detrusor overactivity. Squirting, by contrast, occurs in women with normal pelvic floor function and is not associated with those conditions.

The systematic review that compiled urodynamic data across multiple studies made this distinction especially clear. Women who experienced coital incontinence at penetration showed stress urinary incontinence on testing about 89 percent of the time, and those who leaked at orgasm showed detrusor overactivity in roughly 69 percent of cases. Women who only experienced physiological squirting or ejaculation showed neither condition on the same kinds of provocative tests.² In clinical terms, squirting is considered a non-pathological process. If you experience it and it does not cause you distress, there is nothing medically wrong.

That said, the distinction matters most when someone is bothered by fluid loss during sex and goes to a doctor about it. A clinician familiar with the research will try to determine whether the issue is truly incontinence, which may benefit from pelvic floor therapy, or squirting, which does not require treatment. Misdiagnosis in either direction is unhelpful: labeling normal squirting as a bladder disorder can lead to unnecessary medical intervention, while dismissing true incontinence as “just squirting” can leave a treatable problem unaddressed.

Why the Science Took So Long

Given the prevalence numbers, it seems odd that the scientific understanding of squirting is still relatively new. But the phenomenon was not ignored throughout all of history. A review tracing the history of female ejaculation found references going back millennia. Ancient Chinese Taoist texts from the fourth century described it. Indian texts in the Kāmaśāstra tradition detailed it extensively. Aristotle wrote about female fluid emission around 300 B.C., and Galen discussed it in the second century. In the 17th century, the Dutch physician Reinier de Graaf provided what is considered the first scientific description of female ejaculation and was the first to call the periurethral glands the “female prostate.”¹¹

Despite that long paper trail, the phenomenon largely disappeared from Western medical literature in the 20th century. The shift owed a lot to Freudian psychoanalytic theory, which reframed female sexual response in ways that did not leave room for ejaculation, and to a general tendency in modern medicine to pathologize any involuntary fluid release as incontinence. Ernst Gräfenberg’s 1952 paper on the role of the urethra in female orgasm revived interest, but it took until the early 2000s for imaging and biochemical tools to produce the kind of evidence that settled basic questions about where the fluid comes from.

An Evolutionary Hypothesis

Whether squirting serves any biological purpose is genuinely unclear, and honestly the evidence here is thin. The most developed hypothesis proposes that female ejaculatory secretions provided an antimicrobial benefit. The idea is that PSA-containing fluid flushed through the urethra during or after intercourse could help prevent urinary tract infections, which are a real and significant risk associated with sexual activity. Women less prone to UTIs would be more receptive to frequent intercourse, and thus more likely to conceive.¹²

This remains a hypothesis, not a demonstrated fact. No clinical trial has compared UTI rates between women who squirt and those who do not. The proposal is biologically plausible given what is known about PSA’s antimicrobial properties, but evolutionary “just-so stories” about sexual traits are easy to construct and hard to test. It is equally possible that squirting is simply a byproduct of the anatomical overlap between sexual arousal pathways and urinary voiding pathways, with no adaptive function of its own.

Hormones, Anatomy, and Individual Variation

One reason squirting research is messy is that the experience varies enormously between individuals. Some women report it happening reliably with certain types of stimulation. Others have experienced it only once or twice. Volume ranges wildly, from a small gush to fluid that soaks through bedding. The Skene’s gland variation mentioned earlier is one factor, but there are others.

Hormonal status likely plays a role, though the direct human evidence is limited. Animal studies have shown that estrogen and androgen receptor activity in the female prostate tissue is sensitive to hormonal manipulation.¹³ It is reasonable to suspect that fluctuations in estrogen and testosterone across the menstrual cycle, during pregnancy, or with menopause could change how the Skene’s glands respond during arousal. Some women anecdotally report that squirting became more or less common at different life stages, though controlled data on this is essentially absent.

Pelvic floor strength and tone also seem relevant. Stronger pelvic floor muscles give a person more sensation and control during arousal, and contractions of these muscles during orgasm may facilitate the expulsion. This does not mean pelvic floor exercises will reliably “unlock” squirting for someone who has never experienced it. The relationship between muscle tone and this response has not been tested in a controlled way. But it fits with the broader picture that squirting involves coordination between the bladder, the urethra, the pelvic floor muscles, and the Skene’s glands, all under the influence of autonomic nervous system arousal.

Hydration status at the time of sexual activity is another variable. Because the fluid is primarily bladder-derived, it stands to reason that someone who is well-hydrated and has urine accumulating in the bladder will be more likely to produce a noticeable volume. This is consistent with the wide volume range reported in studies and with common anecdotal observations.

What Researchers Still Get Wrong

Even within the scientific literature, the terminology problem persists. Many older studies use “female ejaculation” as a catch-all for any fluid expulsion during sex, making it hard to compare findings across papers. A 2022 review noted that the conflation of squirting and female ejaculation has muddied the research for decades, and called for standardized definitions.¹⁴ The fact that both can occur simultaneously in the same person, blending together in a way that is impossible to distinguish without lab analysis, makes this harder still.

Sample sizes in squirting studies also tend to be small, often fewer than ten participants for the imaging and biochemical work. This is partly because the research requires participants to become aroused and squirt on demand in a clinical setting while being monitored with ultrasound or having their fluid collected, which is an understandably tall order. The U.S. and Swedish prevalence surveys are larger and more robust, but they capture only self-reported experiences, not physiological measurements. Closing the gap between the detailed mechanistic studies (small and lab-based) and the survey data (large but subjective) is one of the field’s ongoing challenges.