When women squirt, the fluid comes primarily from the bladder and exits through the urethra. This has been confirmed through ultrasound imaging and biochemical analysis of the fluid itself. However, the fluid isn’t identical to regular urine. Small glands near the urethra often contribute additional secretions, making the composition distinct.
What Ultrasound Studies Actually Show
The clearest evidence comes from a study that used ultrasound imaging at three points: before arousal, just before squirting, and immediately after. At the start, all participants had completely empty bladders. During sexual stimulation, the bladders visibly filled with fluid. Immediately after squirting, the bladders were empty again.
This filling-and-emptying pattern was consistent across every participant. The kidneys produce fluid continuously, but the speed of bladder filling during arousal suggests something beyond normal urine production is happening. The bladder appears to fill rapidly during sexual stimulation, and the fluid is then released involuntarily through the urethra.
What’s in the Fluid
Biochemical testing shows that squirting fluid contains urea, creatinine, and uric acid, which are the same chemical markers found in urine. But the concentrations vary. Some studies find lower levels of these markers compared to regular urine, suggesting the fluid is a more diluted version. Other studies find the concentrations are roughly the same.
There’s one important addition. In five out of seven participants in the ultrasound study, the squirting fluid contained prostate-specific antigen (PSA), a protein produced by the Skene’s glands. These are two small glands located on either side of the urethral opening, sometimes called the female prostate. The participants’ urine samples collected before arousal did not contain PSA, but the squirting fluid did. This means the Skene’s glands are contributing their own secretions to the mix, even though the bulk of the volume comes from the bladder.
The fluid also tends to be more transparent and lower in density than typical urine, and it contains little to no glucose or fructose.
Squirting vs. Female Ejaculation
These two terms often get used interchangeably, but researchers now treat them as separate phenomena. Squirting involves 10 milliliters or more of thin, transparent fluid expelled from the bladder through the urethra. Some women release over 100 milliliters. Female ejaculation, by contrast, is a much smaller secretion of just a few milliliters of thicker, whitish fluid that comes directly from the Skene’s glands.
The chemical profiles are different too. Female ejaculate is rich in PSA, glucose, and fructose, closely resembling prostatic fluid. Squirting fluid is dilute and bladder-derived, with only traces of PSA mixed in. Both can happen at the same time, which is part of why they’ve been conflated for so long. But the source organs, volumes, and compositions are distinct.
What Triggers It
Squirting is most commonly associated with stimulation of the front wall of the vagina, the area often referred to as the G-spot. This region sits along the course of the urethra, and the tissue there swells during arousal. It’s part of what researchers call the clitourethrovaginal complex, a cluster of structures including the internal roots of the clitoris, the urethra, and the surrounding tissue that all respond together to pressure and stimulation.
Digital stimulation using one or two fingers with a “come hither” motion against the front vaginal wall is the most commonly studied trigger. In research settings, stimulation of this area led to orgasm in about 73% of cases, and among women who reported having a sensitive area on the front vaginal wall, 82% also reported experiencing some form of fluid expulsion. Brain imaging during vaginal stimulation shows activation patterns that travel through the vagus nerve, bypassing the spinal cord entirely, which may explain why the sensation feels qualitatively different from clitoral stimulation alone.
The fluid release is involuntary. It can happen before, during, or after orgasm, and not every orgasm produces it.
How Common It Is
Estimates vary widely depending on how the question is asked. The International Society for Sexual Medicine cites a prevalence of about 5%, but this likely reflects squirting as a regular occurrence. Survey-based studies paint a different picture. A Swedish cross-sectional study found that 58% of participants had experienced ejaculation or squirting at least once, with higher rates among non-heterosexual women. A U.S.-based study found a prevalence of 41%.
The gap between these numbers reflects genuine uncertainty. Many women may experience small amounts of fluid release without recognizing it as squirting, while others may confuse it with urinary leakage. The Skene’s glands also vary in size from person to person, and some women have more developed glandular tissue than others, which could influence both the likelihood and the character of fluid release.
Why the “Is It Urine?” Question Persists
The short answer is that squirting fluid is mostly bladder-derived, shares key chemical markers with urine, and exits through the same opening. By strict biochemical criteria, it qualifies as a dilute form of urine. But calling it “just urine” misses important nuance. It often contains prostatic secretions absent from normal urine. It’s produced under specific physiological conditions tied to sexual arousal. And the rapid bladder filling observed during stimulation suggests the body is doing something distinct from simply accumulating waste.
Researchers currently describe squirting as “the involuntary emission of urine during sexual activity, although a marginal contribution of prostatic secretions to the emitted fluid often exists.” The scientific understanding is still limited by small sample sizes and the inherent difficulty of studying sexual response in laboratory settings. What is clear is that the fluid originates from the bladder, exits through the urethra, and frequently picks up additional secretions from the Skene’s glands along the way.