Onanism is an archaic term for masturbation that traces back to a 1712 London pamphlet called Onania, which launched roughly two centuries of medical scaremongering about the supposed dangers of self-stimulation. Modern science has thoroughly dismantled that legacy. Research now frames masturbation as a common, generally benign behavior with several measurable physiological effects, some of them beneficial, though the picture is more nuanced than either the old moralists or today’s wellness influencers tend to let on.
How a Pamphlet Became Medical Dogma
The word “onanism” derives loosely from the biblical figure Onan, though the original scripture actually describes coitus interruptus rather than masturbation. The conflation stuck thanks to an anonymous English tract published around 1712, titled Onania; or, The Heinous Sin of Self Pollution. The pamphlet blamed masturbation for a sweeping catalog of physical ailments and was quickly absorbed into mainstream medical thought. For roughly two hundred years, from about 1750 to 1950, Western physicians warned that the “solitary vice” would drain vital bodily energies and cause disorders ranging from acne and epilepsy to insanity and death.1PubMed Central. The solitary vice: the superstition that masturbation could cause mental illness Treatments included everything from bland diets to physical restraints to surgical interventions on the genitals. The medical profession did not begin retreating from this position until the mid-twentieth century, and traces of the stigma persist in cultural attitudes worldwide.
Understanding this history matters because it explains why the topic still carries an unusual emotional charge. Many of the anxieties people express today about masturbation, that it saps energy, causes weakness, harms memory, or ruins sexual performance, are direct descendants of claims made in that 1712 pamphlet and its medical offspring. Evaluating what the evidence actually shows requires first recognizing how recently the old superstitions held official status.
Why Masturbation Exists in the Animal Kingdom
One of the stranger facts about masturbation is that it is not uniquely human. It has been documented across a wide range of species, with observations particularly well-studied in nonhuman primates like rhesus macaques and bonobos, as well as in rodents like African ground squirrels.2PubMed. Masturbation in the Animal Kingdom This breadth suggests the behavior is not simply a byproduct of boredom or captivity, though those explanations have been floated over the years.
A large-scale phylogenetic analysis of primates found support for two functional explanations. The first, sometimes called the postcopulatory selection hypothesis, proposes that masturbation helps males by influencing sperm quality or clearing older sperm before mating. The second, the pathogen avoidance hypothesis, suggests that ejaculation flushes pathogens from the genital tract, reducing infection risk. The analysis found evidence supporting both ideas in male primates, suggesting masturbation may have been maintained by natural selection rather than being a mere quirk of high sex drive.3PubMed Central. The evolution of masturbation is associated with postcopulatory selection and pathogen avoidance in primates Whether these evolutionary explanations translate directly to humans is still debated, but the fertility data discussed later in this article at least rhymes with the postcopulatory selection idea.
What Happens in Your Body During and After
Masturbation to orgasm triggers a short-lived but measurable physiological cascade. Heart rate and blood pressure both rise during arousal and peak at orgasm, then drop back toward baseline. An early electrocardiographic study found increases in QRS and T-wave amplitude, a brief elevation of the ST segment, and a post-ejaculation decrease in heart rate, along with rises in both epinephrine and norepinephrine.4PubMed. Electrocardiographic study of the effect of masturbation normal individuals A later study confirmed that orgasm produces transient spikes in heart rate, blood pressure, and plasma noradrenaline.5PubMed. Neuroendocrine and cardiovascular response to sexual arousal and orgasm in men In healthy people, these fluctuations are brief and comparable to a short burst of moderate exercise. For someone with serious cardiovascular disease, the exertion is worth discussing with a physician, though the actual metabolic demand is modest.
Neurochemically, orgasm floods several signaling systems at once. Dopamine, serotonin, and oxytocin all shift, contributing to the feelings of pleasure, relaxation, and sometimes sleepiness that follow.6Sexuality & Culture. The Memory-Masturbation Link: Analyzing Psychological Impacts and Myths The opioid system also gets involved: orgasm appears to trigger a substantial release of endogenous opioids in reward-related brain regions, which helps explain both the analgesic effect many people notice and the strong reinforcement that makes sexual behavior rewarding.7PubMed. Orgasms, sexual pleasure, and opioid reward mechanisms Animal research has confirmed this directly. In male rats, copulation reduces pain sensitivity as measured by shock-induced vocalization and limb withdrawal, and this effect is blocked by naloxone, a drug that shuts down opioid receptors.8European Journal of Pharmacology. Sexual behavior decreases pain sensitivity and stimulates endogenous opioids in male rats
One small study also found that sexual arousal and orgasm temporarily increase the number of natural killer cells circulating in the blood, a type of immune cell involved in early defense against infections and tumors. Other immune markers like T cells, B cells, and inflammatory cytokines were unaffected.9PubMed. Effects of sexual arousal on lymphocyte subset circulation and cytokine production in man Whether this brief immune bump has any lasting health significance is unknown, but it at least counters the old idea that ejaculation depletes the body’s defenses.
The Testosterone Question
Few topics attract more online mythology than the relationship between masturbation and testosterone. The short answer from the research is that a single episode of masturbation does not meaningfully change testosterone levels. An early study measuring plasma testosterone in seven subjects before and after masturbation found no significant effect.10Journal of Endocrinology. Studies on the Relationship Between Plasma Testosterone Levels and Human Sexual Activity A separate study found that while orgasm itself did not alter testosterone, a preceding three-week period of abstinence did produce elevated testosterone levels.11PubMed. Endocrine response to masturbation-induced orgasm in healthy men following a 3-week sexual abstinence
A more recent pilot study added an interesting wrinkle: while masturbation did not jack up testosterone overall, it did attenuate the natural circadian decline of free testosterone that happens over the course of a day. In other words, testosterone levels that would normally drop as the day wore on fell less steeply after masturbation compared to a control condition of doing nothing.12PubMed Central. Hormonal response after masturbation in young healthy men – a randomized controlled cross-over pilot study This is far from the dramatic testosterone crash that “semen retention” communities warn about, but it is also not the testosterone boost that some wellness marketers promise. The honest summary: the hormonal effects of occasional masturbation are small and transient, and unlikely to affect muscle growth, energy, or mood in any noticeable way.
Ejaculation Frequency and Prostate Cancer
The most-cited health finding related to ejaculation frequency comes from a large prospective study of predominantly white men, which found that higher ejaculation frequency was not associated with increased prostate cancer risk. In fact, the data suggested a possible protective association.13JAMA. Ejaculation Frequency and Subsequent Risk of Prostate Cancer A follow-up analysis with an additional decade of data strengthened this finding: men who ejaculated at least 21 times per month had roughly a 20% lower risk of prostate cancer compared with men who ejaculated four to seven times per month, with results holding for both younger and middle-aged men. The association was strongest for low-risk, organ-confined disease.14PubMed Central. Ejaculation Frequency and Risk of Prostate Cancer: Updated Results with an Additional Decade of Follow-up
Before anyone prescribes themselves a strict ejaculation schedule, some caveats are important. The data are observational, meaning they show a correlation, not proof that ejaculation itself prevents cancer. A narrative review of the broader literature noted that while some studies support this inverse relationship, others have found conflicting results, and the overall evidence base still calls for cautious interpretation.15PubMed. Ejaculation Frequency and Prostate Cancer Risk: A Narrative Review of Current Evidence The biological mechanism, if real, likely involves clearing the prostate of potentially carcinogenic secretions, reducing inflammatory stasis, or some combination of both. It is plausible, but not proven.
Sperm Quality and Fertility
For people trying to conceive, the frequency of ejaculation matters in a practical and sometimes counterintuitive way. The conventional advice was to “save up” by abstaining for several days before attempting conception. More recent evidence points in the opposite direction for many men. Prolonged abstinence of four or more days increases semen volume and raw sperm count, but at a cost: motility drops and DNA fragmentation rises.16PubMed Central. Ejaculatory frequency and male fertility: a literature review of evidence-based recommendations A cross-sectional study confirmed this trade-off, finding that as ejaculation frequency increased, DNA fragmentation fell and sperm vitality improved, even though total sperm count and semen volume went down.17PubMed Central. Impact of ejaculation frequency on semen parameters and DNA fragmentation: a cross-sectional study
Additional data fleshed out the pattern: after just one day of abstinence, mean semen volume was about 1.8 mL with progressive motility near 68%, while after six or more days, volume nearly doubled to about 3.5 mL but progressive motility fell to around 54% and normal morphology also declined.18Genetics and Molecular Research. Frequency Matters: Unraveling the Association Between Ejaculatory Frequency and Sperm Quality The practical takeaway is that for couples undergoing fertility treatment or trying naturally, shorter abstinence periods (one to two days) tend to produce healthier, more motile sperm with less DNA damage. “Saving up” produces a bigger sample but not a better one.
Sleep, Stress, and Mood
Many people report that masturbation helps them fall asleep, and there is some empirical support for this. A pilot study comparing nights following solo masturbation, partnered sex, and no sexual activity found that sleep quality improved after both sexual conditions. Wake time after falling asleep averaged about 23 minutes on no-sex nights compared with about 16 minutes after solo masturbation and after partnered sex. Sleep efficiency also improved, though the difference was statistically strongest for the partnered-sex condition.19Elsevier / Sleep Health. The impact of sexual activity on objective and subjective sleep parameters: a pilot study The likely mechanism involves the oxytocin and prolactin release that follows orgasm, both of which promote relaxation and drowsiness.
Beyond sleep, qualitative research with women found that many deliberately use masturbation as a coping strategy for stress, difficulty falling asleep, and physical pain. Participants described it as “self-care” and “me-time,” reporting emotions like calm, contentment, and a general sense of well-being afterward.20PubMed Central. Exploring the Role of Masturbation as a Coping Strategy in Women This lines up with the neurochemistry: the dopamine, serotonin, and endogenous opioid shifts described earlier collectively produce a short-term mood lift and anxiolytic effect. The research on memory fears is similarly reassuring. A review found no strong scientific basis for the belief that masturbation directly harms memory; moderate masturbation may actually support cognitive function indirectly by relieving stress, though compulsive patterns paired with excessive pornography consumption have been linked to attentional difficulties.21Sexuality & Culture. The Memory-Masturbation Link: Analyzing Psychological Impacts and Myths
When It Becomes a Problem
The line between healthy and problematic masturbation is not about frequency per se. It is about consequences. The World Health Organization’s ICD-11 includes compulsive sexual behavior disorder as an impulse control condition, though the diagnostic criteria have been debated. Compared with earlier proposed criteria for “hypersexual disorder,” the ICD-11 formulation notably adds moral incongruence as an exclusion: if someone’s distress about their behavior stems primarily from feeling it violates their moral or religious beliefs rather than from actual functional impairment, that alone does not qualify as a disorder.22PubMed Central. What should be included in the criteria for compulsive sexual behavior disorder? This distinction is clinically important. A substantial share of people who seek treatment for “sex addiction” or “porn addiction” turn out to have average-frequency sexual behavior and high levels of religious or moral guilt.
A separate physical concern involves how someone masturbates rather than how often. Atypical techniques, such as rubbing against surfaces while prone or stimulating through clothing with unusual pressure, have been associated with later erectile difficulties. One study found that these “traumatic” masturbation styles were significantly more common among men presenting with erectile dysfunction.23PubMed. Traumatic masturbation syndrome may be an important cause of erectile dysfunction in pre-mature ejaculation patients The concern is conditioning: the body learns to respond to a very specific type of stimulation that partnered sex cannot replicate. For men experiencing this, the fix is usually retraining with more conventional stimulation, sometimes alongside pelvic floor work. A narrative review of pelvic floor rehabilitation found that strengthening and normalizing pelvic floor muscle tone can improve both erectile dysfunction and premature ejaculation, particularly when manual therapy is combined with targeted exercises.24Sexual Medicine Reviews. The Effect of Pelvic Floor Rehabilitation on Males with Sexual Dysfunction: A Narrative Review
The Guilt Factor
For many people, the biggest downside of masturbation is not physical but psychological, and it is culturally manufactured. Despite being nearly universal, masturbation is prohibited or discouraged by most major religious traditions. This creates a collision between behavior and belief that researchers now describe as moral incongruence, and its consequences can be genuinely harmful.25Sexuality & Culture. Taught to be Ashamed: Sexual Shame, Faith, and Moral Incongruence in Men’s Psychosexual Development Cultural myths about masturbation, including the belief that it causes physical weakness or spiritual harm, have been linked to clinical presentations of masturbatory guilt and Dhat syndrome, a condition seen primarily in South Asian cultures involving intense anxiety about semen loss.26PubMed Central. Can masturbatory guilt lead to severe psychopathology: a case series
A study of Jewish religious single men found that sexual guilt and shame related to behaviors like masturbation was positively associated with anxiety and depression and negatively associated with life satisfaction.27PubMed. The Moderating Effect of Religiousness on the Relation Between Sexual Guilt and Shame and Well-Being Among Jewish Religious Single Men The distress in these cases is real, but its source is the conflict between the act and the belief system, not the act itself. This is exactly the distinction the ICD-11’s moral incongruence exclusion is trying to capture. Therapists working with clients in this space increasingly focus on resolving the incongruence, whether that means adjusting behavior to align with values or examining whether the values themselves were imposed in ways the client no longer endorses, rather than treating the sexual behavior as inherently disordered.
Sex Differences in Self-Pleasure
Research on masturbation has historically focused on men, partly because male masturbation is more culturally visible and partly because the prostate-cancer data set is such a large epidemiological magnet. But the picture for women has its own specifics worth knowing. Major professional organizations like the American Academy of Pediatrics recognize masturbation as a normal component of child and adolescent development regardless of sex, and recommend that health providers include it in sexuality discussions during preventive visits.28JAMA Pediatrics. Prevalence, Frequency, and Associations of Masturbation With Partnered Sexual Behaviors Among US Adolescents
One area where masturbation plays a distinct role for women involves orgasm. In a study of undergraduate women, about 83% of those who had experienced orgasm from masturbation identified clitoral stimulation alone as their most reliable route, compared with just 1% who named vaginal penetration alone. During partnered sex, the pattern shifted: roughly 76% of women who had experienced partnered orgasm cited simultaneous vaginal and clitoral stimulation as most reliable, while only about 7% relied on penetration alone.29JSM Sexual Medicine. Heterosexual Women’s Most Reliable Route to Orgasm during Partnered Sex Versus Masturbation Masturbation, in this context, serves as a tool for self-knowledge. Women who understand their own arousal patterns through solo exploration are better positioned to communicate those patterns to partners, which is a practical payoff that no amount of moralizing should be allowed to obscure.
Connected Devices and Changing Norms
The way people masturbate is changing along with technology. A latent class analysis of male users of connected sex toys identified four distinct motivational profiles among 569 participants. The largest group, making up about 38%, were labeled “solo comfort seekers” who used devices mainly as a substitute for a partner and regularly combined them with pornography. About 30% were “low-regulation users” who showed the weakest endorsement of relaxation or boredom-relief motives. Roughly 23% were “standalone toy users” who preferred manual devices and showed little interest in digital integration. The smallest group, about 9%, were “tech-integrated regulators” who strongly endorsed all motivations and almost always used teledildonic devices with pornography.30SpringerLink / Archives of Sexual Behavior. Why Do Male Users Engage with Connected Sex Toys? A Latent Class Analysis of Motivational Profiles
What this snapshot captures is the growing normalization and diversification of solo sexual behavior. Sex toys are no longer niche novelty items; they are consumer electronics with app connectivity, and people use them for reasons ranging from partner absence to deliberate relaxation. This shift is eroding some of the secrecy and shame historically attached to masturbation, though it also introduces new questions. The interplay between connected devices, pornography, and potentially compulsive patterns is still poorly understood, and the research is in its infancy. For most users, the technology simply expands the menu of available stimulation. For a smaller subset, particularly those already prone to compulsive sexual behavior, the frictionless access and novelty escalation may warrant self-awareness.