Pre-cum, or pre-ejaculatory fluid, is a clear, slippery liquid that seeps from the tip of the penis during sexual arousal, before ejaculation. It’s produced by two small glands located below the prostate, and its release is completely involuntary. You can’t control when or how much comes out, and you may not even notice it happening.
Where It Comes From
Pre-cum is secreted by a pair of pea-sized glands called the bulbourethral glands, which sit just below the prostate and connect to the urethra. When arousal begins, these glands release fluid that coats the inside of the urethra. The fluid serves two main purposes: it neutralizes residual acidity left behind by urine (creating a more favorable environment for sperm that will follow during ejaculation), and it acts as a natural lubricant during sex.
The volume varies widely from person to person. Some men produce barely a drop, while others produce several milliliters. Duration and intensity of arousal, hydration levels, and individual biology all play a role. There’s no “normal” amount, and producing very little or quite a lot are both common.
Can You Feel or Control It?
Pre-cum is involuntary. Unlike ejaculation, which involves a distinct physical sensation and muscular contractions, pre-cum simply seeps out. You might notice a bit of wetness at the tip of the penis, but during sex or other stimulation, it’s easy to miss entirely. There’s no way to hold it back or force it out on command.
Can Pre-Cum Contain Sperm?
This is the question most people are really asking, and the answer is: sometimes, yes. The glands that produce pre-cum don’t generate sperm themselves, but sperm can end up in the fluid.
A study examining 40 pre-ejaculatory samples from 27 men found that 41% of the men produced pre-cum containing sperm, and in most of those cases the sperm were motile, meaning they were still capable of swimming. A separate, more recent pilot study of 24 men found sperm in about 13% of pre-ejaculate samples, though the concentrations were usually too low to pose a significant pregnancy risk on their own.
The most likely explanation for sperm showing up in pre-cum is that leftover sperm from a previous ejaculation remain in the urethra and get picked up by the fluid as it passes through. Urinating between ejaculations may help flush out residual sperm, though this hasn’t been rigorously tested.
Pregnancy Risk and the Withdrawal Method
Pre-cum is the reason the withdrawal method (pulling out before ejaculation) isn’t considered highly reliable contraception. With perfect use, meaning the man withdraws completely every single time before any ejaculation occurs, the failure rate is about 4% per year. With typical use, which accounts for real-world mistakes like withdrawing too late, the failure rate jumps to 18% per year. That means roughly 1 in 5 couples relying on withdrawal alone will experience a pregnancy within a year.
Most of that 18% failure rate comes from imperfect timing rather than sperm in pre-cum. But because some men do carry motile sperm in their pre-ejaculatory fluid, there is a small pregnancy risk even with perfect withdrawal. If avoiding pregnancy matters to you, combining withdrawal with another method (like condoms or hormonal contraception) significantly reduces the odds.
STI Transmission Through Pre-Cum
Pre-cum can carry sexually transmitted infections. This is true for both viral and bacterial infections, and it’s one of the most overlooked risks of unprotected sexual contact, even without ejaculation.
HIV is the most studied example. Pre-ejaculatory fluid from HIV-positive men has been shown to contain both the virus and infected white blood cells. Delayed condom use (putting a condom on partway through sex rather than from the start) is an established risk factor for HIV transmission among men who have sex with men, strongly suggesting that pre-cum itself can be infectious. One important exception: in men whose HIV is fully suppressed through antiretroviral therapy, researchers found the virus was undetectable in pre-ejaculatory fluid, even when low levels were still present in semen.
Beyond HIV, other infections transmitted through genital fluids, including chlamydia, gonorrhea, and hepatitis B, can also be present in pre-cum. Condoms are the only method that reduces this risk, and they need to be on before any genital contact occurs, not just before ejaculation.
Why Some People Produce More Than Others
The amount of pre-cum a person produces is largely down to individual physiology. Some men consistently produce enough to visibly wet clothing, while others rarely notice any at all. Both are normal. Higher levels of arousal and longer periods of stimulation tend to produce more fluid, but the baseline varies so much between individuals that comparison isn’t meaningful. Certain medications, particularly those that affect hormones or fluid balance, can also influence production, but there’s no established way to intentionally increase or decrease the amount.