Masturbation side effects: what's real and what's a myth

Short answer

Masturbation side effects are few, usually minor, and mostly about the skin. Cleveland Clinic's overview says masturbation "doesn't have any serious side effects"; rubbing roughly can cause chafing or tender skin, and many sessions close together can cause slight swelling, which should heal within a day or two (1). Rare injuries do happen, and guilt or a pattern that feels out of control can weigh on people more than any physical effect.

Most of the famous harms are myths. We found no study showing that masturbation causes hair loss, kidney disease, acne, weight change, blindness or infertility. Below we take each claim in turn, and say plainly where research doesn't exist.

If you came here worried, that worry is common and it is not a moral failing. In a 2021 nationally representative US survey, most men and more than half of women had masturbated in the past year (2); the survey was funded by a men's telehealth company, which did not take part in data collection or analysis.

Note: this article explains what research says and is not medical advice. It is for adults and covers health questions only. Pain, bleeding or injury needs a clinician; an erection lasting more than four hours is an emergency-room visit; and if you are having thoughts of harming yourself, call or text 988.

Masturbation side effects: what's real and what's a myth

The real side effects are local and usually short-lived; the myths are about distant organs and the whole body.

"We found no study" means we searched the research databases and found nothing testing that link, so there is nothing to weigh. In those cases we give what does cause hair loss, kidney disease or acne instead.

Is masturbation bad for your health?

No. For most adults it is a normal, low-risk behavior, and the medical sources we reviewed list no serious physical side effects (1). It carries no risk of pregnancy, and STI transmission through masturbation is rare, though shared items can carry infections (1, 14).

In the 2021 US survey, pleasure was the most common reason people gave for masturbating, and about a quarter of women and a fifth of men said it helped them fall asleep (2). Orgasm tends to feel better without pressure or fear of being interrupted; lack of privacy was one reason some people gave for not masturbating (2). These are self-reports: they describe experience, not physiology. (See also: female masturbation.)

When masturbation does become a health question, it is usually because of an injury or skin problem, a sense of being unable to stop, or guilt that won't lift.

Masturbation side effects for men

For men, the real side effects range from common and trivial (sore skin) to rare and urgent (penile fracture, priapism).

Chafing, tenderness and swelling. Rough or prolonged stimulation can chafe the skin, and repeated sessions in a short time can make the penis slightly swollen; these minor effects "should heal within a day or two," and a lubricant can reduce friction (1). Skin that cracks, bleeds or stays sore beyond a few days needs a clinician.

A firm cord under the skin. Sclerosing lymphangitis is a rare, hard, minimally tender cord near the head of the penis. It most often follows vigorous sexual activity and resolves on its own, but in a small case series it was sometimes linked to a sexually transmitted infection that needed treatment (15), so a new lump is worth showing to a doctor.

Penile fracture. This is a rare tear in the tough casing around the erectile tissue of an erect penis. Reviews differ on how often masturbation is involved: a meta-analysis of 3,213 patients found intercourse behind 48% of cases, with masturbation and forced bending together behind 39% (3), while a review of 438 surgically treated men found intercourse behind 80% (16). The typical picture is a "sudden cracking or popping sound, pain and immediate detumescence" (loss of erection), then swelling and discoloration (37). A crack or pop, sudden loss of erection, then swelling or bruising: go to the emergency room the same day. In that meta-analysis, early surgery was associated with fewer complications than delayed repair (3).

An erection that won't go down. Priapism is an erection lasting more than four hours; NIDDK lists it as a possible side effect of erectile dysfunction medicines and says to seek care right away (4). The American Urological Association's guideline says all patients with priapism "should be evaluated emergently," because the low-blood-flow type can damage erectile tissue (5). An erection lasting more than four hours: go to the emergency room or call 911.

Reduced sensitivity and erections. Masturbating very often or very aggressively may reduce sexual sensation (1); grip, pornography and erections are a separate topic with mixed evidence. What isn't mixed: new erectile problems deserve a doctor's visit, because erectile dysfunction in younger men was associated with a marked rise in later heart events (17). See your sex life as a vital sign for heart and hormones and male libido, erections and lifestyle.

Can masturbation cause blood in semen?

Occasionally, and it is usually harmless, but it should still be checked. Blood in semen (hematospermia) is considered by many specialists "a self-limiting and usually benign condition," and a urology review lists "excessive sex or masturbation" among possible causes (18). In one series of 300 men, no cause was found in 81%, but cancers were found more often in men over 40 (6.2% versus 1.4%) (18). Blood in semen that keeps coming back, comes with pain or fever, or appears after 40 belongs in front of a doctor.

Feeling ill after orgasm

A few men feel flu-like, foggy and exhausted for hours or days after every ejaculation. This is postorgasmic illness syndrome (POIS), rare and of unknown cause (19). In the largest survey, of 302 men from an online patient community, the most common symptoms were difficulty concentrating (84%), extreme fatigue (83%) and irritability (74%) (19). Ordinary drowsiness after orgasm is not POIS; a pattern that reliably disrupts your life is worth raising with a urologist.

Masturbation side effects for women

For women, the real side effects are mostly irritation and soreness, plus questions about lubricants and cleaning. Serious injury is rare, and pain is the signal to stop.

Irritation. The American College of Obstetricians and Gynecologists (ACOG) describes contact dermatitis of the vulva as a reaction to an irritating substance, "such as perfumed soaps, douches, or lubricants," which may cause itching, burning and pain; it calls water-soluble lubricants "a good choice" for irritation or sensitivity (20).

Lubricant compatibility, in general terms. A 2025 clinical review notes that oil-based lubricants can damage latex, silicone-based lubricants can degrade silicone items, and water-based lubricants were compatible with every material it reviewed (21). It also notes that many items designed for genital use are unregulated, and that petroleum jelly has been linked to a higher risk of bacterial vaginosis (21). A clearly labeled, body-safe material is the safer choice.

Cleaning and sharing. Clean anything you use after use (1). In a small study of 12 women, human papillomavirus (HPV) was found on vibrators after use, often still right after cleaning, and on one of two materials a day later (14), so sharing items carries some infection risk.

How often problems happen. Rarely. In a nationally representative US study of women aged 18 to 60, 52.5% had used a vibrator, and use was "rarely associated with side effects" (22).

Stop if it hurts. New pain during any sexual activity, bleeding, a cut, or irritation that hasn't cleared in a few days means seeing a gynecologist or primary care clinician. Pain with sex has many treatable causes, from infections to vulvodynia and hormone changes around menopause (20). If desire itself has changed, see women's libido, stress, sleep and the cycle.

A headache with orgasm, for anyone

A rare side effect for women and men alike is a headache brought on by sexual activity, typically a dull ache that builds with arousal and turns intense at orgasm. The international headache classification recognizes it and says that the first time it happens, doctors must rule out bleeding in the brain and other vascular causes (23). A sudden, severe headache during or after sex, or one with vomiting, confusion, weakness or vision changes: call 911.

Does masturbation cause weight loss?

No. Sexual activity uses some energy, but no study shows that it changes body weight, and masturbation probably uses less than partnered sex.

The best measurement comes from partnered sex. In a 2013 study, 21 young couples wore activity armbands at home; sessions averaged about 25 minutes, and men used an average of 101 kcal and women 69 kcal, against 276 and 213 kcal for 30 minutes on a treadmill at moderate intensity (8). The participants were fit and in their early twenties, so the numbers don't stretch to everyone.

A 2013 review of obesity myths in the New England Journal of Medicine estimated that a 154-lb man burns about 21 kcal in an average six-minute bout, roughly a third of which he would have burned watching television, so the extra cost is around 14 kcal (24). It listed "a bout of sexual activity burns 100 to 300 kcal" as a myth.

How many calories does masturbation burn?

Probably very few, and no modern study has measured it. In a 1984 lab study of ten healthy men, self-stimulation required lower energy than the two intercourse positions tested; effort peaked briefly at orgasm and quickly returned to near baseline (9). The authors noted large differences between people, so the honest answer is "less than the figures above," not a number.

And weight gain? We found no study linking masturbation to weight gain either. Weight that changes without an obvious reason is worth a medical visit in its own right.

Can masturbation cause hair loss?

There is no evidence that it does. We found no study linking masturbation or ejaculation to hair loss, and the American Academy of Dermatology's list of 18 causes of hair loss does not include it (10).

Where the idea comes from. The most common hair loss, hereditary pattern hair loss (androgenetic alopecia), is related to the androgen dihydrotestosterone (DHT), along with genes and other factors still unknown (11). The myth runs: masturbation raises testosterone, which becomes DHT, which thins hair. The first step doesn't hold. In a small study of ten men, plasma testosterone was "unaltered by orgasm" from masturbation, and was higher after three weeks of abstinence instead (25). Testosterone after 40: myths and facts covers the hormone side. (See also: whether masturbation lowers testosterone.)

What does cause hair loss. The AAD calls hereditary hair loss the most common cause worldwide, in women and men, and lists others including alopecia areata, illness, childbirth and other stressors, thyroid disease, hormonal imbalance, some medicines, tight hairstyles, and low iron, protein, zinc or biotin (10). Sudden, patchy or heavy shedding is worth a dermatologist's visit.

Masturbation effects on kidney: what the evidence shows

Biomedical research hasn't found any effect of masturbation on the kidneys. We found no study linking it to kidney disease or to changes in kidney function tests.

Why the question exists. Many people ask because of traditional frameworks, and those deserve respect. In traditional Chinese medicine (TCM), "Kidney" names a pattern diagnosed from symptoms and a practitioner's observations; a study building a Kidney deficiency questionnaire notes that the classic TCM literature lists, for men, symptoms such as nocturnal emission, premature ejaculation and infertility (26). That is a different concept from the anatomical kidneys that filter blood. In South Asia and elsewhere, a related belief holds that losing semen drains vitality; researchers have traced versions of it across many cultures, historically including Britain, the US and Australia (27). This article doesn't argue with any tradition; it reports what biomedical evidence shows.

What biomedical evidence shows. NIDDK states that "the most common causes of chronic kidney disease (CKD) in adults are diabetes and high blood pressure," and lists others such as autoimmune disorders, kidney-toxic drugs, infections and inherited conditions (12). Masturbation isn't among them. Kidney function is checked with a blood test (glomerular filtration rate, GFR) and a urine test for albumin (28).

If the worry won't go away. Back pain, tiredness or frequent urination have many possible explanations, and a doctor can run those two tests and check blood pressure and blood sugar. If worry about semen loss is itself causing distress, a therapist who respects your background can help.

Does masturbation cause acne?

No study we found shows that it does. MedlinePlus, from the US National Library of Medicine, says "no one knows exactly what causes acne," that hormone changes probably play a role, and that stress doesn't cause acne but can make it worse (13). The masturbation idea rides on the same testosterone reasoning as the hair-loss myth, and the same weak link applies: orgasm from masturbation didn't change plasma testosterone in the small study that measured it (25).

Acne that is severe, scarring, or arrives with irregular periods or excess hair growth is a reason to see a dermatologist or primary care clinician. Polycystic ovary syndrome, for example, is a hormonal imbalance that can cause all three (11).

Blindness, infertility and "weakness": where the old myths came from

Many of these myths trace back to the eighteenth century, when masturbation was moved "from the moral to the medical sphere" and blamed for deteriorating physical illnesses; nineteenth-century psychiatrists even proposed a "masturbatory insanity," promoted to the public "by quacks peddling quick cures" (29). Medicine later abandoned the idea. Cleveland Clinic lists vision loss, hairy palms, mental illness, shrinkage or curvature of the penis, lower sperm count, erectile dysfunction, lower libido and infertility as myths (1).

Does masturbation cause low sperm count?

No (1). If anything, fertility research points the other way: in an analysis of 9,489 semen samples, men with low counts had their best sperm motility after one day of abstinence, while normal samples showed lower motility and fewer normally shaped sperm after 11 to 14 days (30). For women, we found no study linking masturbation to infertility. If pregnancy isn't happening, ask a clinician rather than changing your frequency.

Does masturbation make you weak?

Not in any way research has detected, though the evidence is thin. A systematic review found most studies "generally seem to exclude a direct impact" of sexual activity on aerobic and strength performance, and noted that masturbation itself hasn't been studied (31). In a small crossover study of eight adults, sex the night before made no measurable difference to grip strength, jump height, push-ups or reaction time (32). Feeling sleepy right after orgasm is common and brief; feeling ill for days is the rare POIS pattern above.

Guilt, distress and compulsive patterns: the side effects that are real

For many people the most noticeable side effect is emotional. Guilt is common, and it usually comes from beliefs and upbringing rather than anything the body is doing.

Guilt. Cleveland Clinic lists guilt and shame among masturbation's unwanted effects, often tied to religious, spiritual or cultural beliefs, and suggests a sexual health therapist or counselor (1). How common it is depends on the setting: in a retrospective study of married men attending one clinic in China, 76.6% of those who masturbated reported at least some guilt, and more guilt went with slightly higher anxiety and depression scores (6). One clinic's patients may not reflect the wider population, and the design can't show which came first. (See also: masturbation, guilt and anxiety.)

When values and behavior pull apart. Research on pornography use calls this mismatch moral incongruence, and a meta-analysis found it was a strong predictor of feeling "addicted" (33). The distress is real; the most helpful conversation may be about values, with someone who respects them.

A pattern that feels out of control. "Porn addiction" and "sex addiction" are not DSM-5 diagnoses; the American Psychiatric Association considered criteria for "hypersexual disorder" and left them out (38). The WHO's ICD-11 includes compulsive sexual behaviour disorder (6C72): "a persistent pattern of failure to control intense, repetitive sexual impulses or urges" over an extended period, with marked distress or impairment; distress that comes only from moral judgments doesn't qualify (7). In a US sample of adults aged 18 to 50, 10.3% of men and 7.0% of women screened positive for clinically relevant distress about controlling sexual urges (34).

When to talk to someone. Repeated failed attempts to cut down, missed sleep or commitments, or shame that won't lift are reasons to see a licensed therapist, ideally one trained in sexual health. If distress turns into thoughts of harming yourself, call or text 988 (35). For anxiety around sex, see sexual performance anxiety, stress and arousal.

Masturbation side effects: the questions people ask next

Does masturbation affect penis size?

No. Cleveland Clinic lists "shrinkage or curvature of your penis" among masturbation myths (1), and we found no study showing that masturbation changes penis size in either direction. Two things do deserve a doctor's attention: a new curve or a hard lump in the shaft, and a sudden injury with a crack or pop and bruising, which is an emergency (37). Neither comes from ordinary masturbation, but both need an exam rather than a wait-and-see approach.

Can masturbation cause prostate cancer?

There is no evidence that it does. The largest study followed 31,925 US men from 1992 to 2010 and found that reporting 21 or more ejaculations a month was associated with a somewhat lower risk of prostate cancer than reporting 4 to 7, mostly for low-risk disease (36). It did not separate masturbation from sex, and an observational link can't be turned into a prevention plan. If prostate cancer is on your mind because of family history, urinary symptoms or age, ask your doctor about screening.

Can masturbation cause testicular cancer?

We found no study linking masturbation to testicular cancer. The worry often starts when someone notices a lump or ache, and that is the moment to act: any new lump, swelling, heaviness or persistent ache in a testicle deserves a prompt doctor's visit, whatever you think caused it. Sudden severe testicular pain is an emergency. It can mean a twisted testicle, and MedlinePlus advises emergency care as soon as possible, since most of the testicle can be saved if surgery happens within 6 hours (39).

Does masturbation affect muscle growth?

Not in any way research has shown. In the small study that measured hormones around masturbation, orgasm didn't change plasma testosterone (25), and a systematic review found no direct effect of sexual activity on strength or aerobic performance, while noting that masturbation itself hasn't been studied in this context (31). If you lift and want the hormone details, testosterone after 40: myths and facts covers them.

Is it normal to feel guilty after masturbating?

It is common, and it isn't a sign that something is physically wrong. Guilt usually reflects what you were taught or believe (1). Among US adults who hadn't masturbated in the past year, 4.2% of women and 4.8% of men gave "I feel bad about myself afterwards" as a reason (2). For some people guilt fades with information; for others it is tied to faith or family. A sexual health therapist can help either way, without asking you to give up your values.

What if masturbation conflicts with my religion or values?

That is a legitimate position, and this article doesn't argue with it; it covers health questions only. In the 2021 US survey, 11.3% of women and 13.8% of men who hadn't masturbated in the past year said it was against their morals or values, and 8.0% and 9.4% said it was against their religion (2). From a health point of view, not masturbating is also normal and carries no known physical risk. If the conflict itself causes distress, a therapist who respects your faith can help.

When to see a doctor or a therapist

Go to the emergency room or call 911 for: a crack or pop followed by sudden loss of erection, swelling or bruising (37); an erection lasting more than four hours (5); a sudden, severe headache during or after sex (23); sudden severe testicular pain (39).

See a clinician soon for: pain, bleeding or a wound that doesn't heal in a few days; a new lump or cord on the penis or in a testicle (15); blood in semen that recurs or appears after 40 (18); vulvar irritation that doesn't clear, or new pain during sex (20); feeling ill for days after orgasm (19). New erectile problems also mean a doctor's visit (17).

See a licensed therapist for distress or compulsive patterns (7). Call or text 988 if you have thoughts of harming yourself (35).

What to say. One sentence is enough: "I've had soreness that isn't healing," "I noticed blood in my semen twice this month," or "I'm worried masturbation is affecting my kidneys." You only need to share as much detail as the problem requires.

What to bring. A short dated note: when it started, how often it happens, anything new (a medication, a product), and other symptoms such as fever, pain or urinary changes.

What to ask.

• "Is this a medical concern, and does it need a test?"

• "Could a product, a medication or a skin condition explain it?"

• "If it's not physical, can you refer me to a sex therapist?"

Start understanding your body

Learn what affects your energy, stress, sleep, and daily state. Get the app.

Explore your data

How Welltory helps — and what it cannot do

The limits first. Welltory is a general wellness product, not a medical device. It does not diagnose, detect, predict, monitor, prevent, treat or mitigate any condition, including injuries, erectile dysfunction, kidney disease, hair loss, acne or compulsive sexual behaviour. It knows nothing about your sex life, it is not a tool for counting masturbation, and nothing in it tells you whether something is a side effect.

You note the evening; the app records the rest. When Welltory flags a stress stretch or a rest stretch on the Today screen, it asks "What happened?" or "What helped you rest?" You can tap a suggested tag, type a few words or just talk, in whatever words you're comfortable keeping on your phone: "wind-down", "late night", "felt guilty", "early night". Welltory picks the tags out of your answer, and you can correct them before saving.

Then look at the days after. Sleep analysis, stress minutes, Battery, resting heart rate and HRV are recorded the same way every day (stress minutes, sleep analysis and Battery need a supported wearable). Set tagged evenings beside the sleep and the day that followed and, over a few weeks, you see your own pattern: your numbers next to your own history, not a population range and not a line marked normal.

After two to three weeks of tagging, My Patterns has something to work with. My Patterns collects tags from stress and rest stretches, so it needs iOS with an Apple Watch or Oura; patterns start to appear at around seven tagged events in the current month. It shows which tagged situations tend to come with stressful stretches, trends by day of week, and every time a tag occurred.

A record you made, for an appointment if you want one. The Journal (Premium) keeps your measurements, tags and notes, and the Welltory web app exports a CSV (Dashboard → choose a chart → Export). If you see a doctor or therapist about sleep, stress, guilt or desire, dated notes are easier to describe than memory. Any pattern is an association to discuss, not a cause.

The same red flags apply here, in the same type size: pain, bleeding or injury means a clinician; a crack or pop with swelling, or an erection lasting more than four hours, means the emergency room or 911; new erectile problems mean a doctor's visit; distress or compulsive patterns mean a licensed therapist; thoughts of self-harm mean calling or texting 988 (5, 17, 35).

Where to find other people in the same situation. If you are also living with an energy-limiting condition, Welltory runs a paid, moderated community called Energy Lab for women aged 18 to 65 living with ME/CFS, long COVID, fibromyalgia, POTS, MCAS and similar. It runs alongside the app: you keep collecting your own data, and the Lab is where people learn to read it together, with a medical board answering the science. It is education and peer support, not medical care, it does not replace your clinician, and there is a 14-day money-back guarantee on a first purchase.

How we made it

Made with AI tools, then edited and fact-checked by the Welltory team. See our Editorial & AI policy.

Data analysis by Jane Smorodnikova, co-founder of Welltory and the person who built the methodology behind how we read physiological data.

Written by Tatsiana Yashyna.

Discounts for blog readers: up to 36% off

See what affects your energy, stress, sleep, and daily state with Welltory

Explore your data