Men's sex questions, answered

Some questions about sex are easier to type than to ask. Here are short answers to the ones men search for most, each drawn from the NHS, UK specialists' bodies or published studies, with the source named and a link to the full piece.

What is the average penis size?

A 2021 review puts the average length of an erect penis between 5.1 and 5.5 inches (12.95 to 13.97 cm), and probably towards the lower end of that range once volunteer bias is taken into account. A 2015 review of studies in which health professionals measured up to 15,521 men found an average erect length of 13.12 cm, an average soft length of 9.16 cm and an average erect girth of 11.66 cm.

In a UK study of 609 men, set up to establish a reference range, the average soft length was 8.7 cm. Figures from men measuring themselves run higher: the 2021 review found that several often-cited studies based on men's own measurements averaged about 6.2 inches (for heterosexual men) and suffered from volunteer bias and social desirability bias. The full picture, with the UK figures and how to measure, is in average penis size: what the studies show.

Does circumcision reduce sensitivity?

The NHS says circumcision usually leads to loss of sensitivity of the head of the penis, which may be noticeable during sex, but shouldn't have a major effect on your sex life in the long term. Studies of sensitivity and of sex afterwards disagree.

A 2013 review found that the higher-quality studies showed no overall adverse effect on sensitivity or satisfaction. An online survey of 1,369 men, led from Belgium, found circumcised men reported less pleasure at the head of the penis. In Britain, the Natsal-3 survey estimated that 20.7% of men are circumcised. Every study, with its size and limits, is in circumcision in men: recovery, risks and the research on sensitivity.

Is blue balls real?

Plenty of people report it, though it has barely been studied. In a 2023 online survey, 56% of 1,483 people with a penis said their testicles or the area around them had hurt or ached when they approached orgasm without ejaculating.

Most who rated the pain called it mild, and the study says it appears to resolve on its own, usually over a few minutes to hours, or with orgasm. The same study concludes that the pain is not a valid reason to continue unwanted sexual activity. Testicle pain that's sudden and severe, or lasts more than an hour, needs A&E. More on causes and relief: blue balls: is it real?

How long does sex last?

In studies that timed vaginal sex between men and women, the average time from penetration to ejaculation was about five and a half minutes. The British Association of Urological Surgeons (BAUS) puts the average time taken to ejaculate during intercourse at around 5½ minutes. A 2005 study of 500 couples in five countries, including the UK, timed vaginal sex with a stopwatch and found a median of 5.4 minutes, ranging from 0.55 to 44.1 minutes.

BAUS adds that it's up to each couple to decide whether they're happy with the time taken. The timing studies are set out in how long should sex last?, and the options in how to last longer in bed.

Does Viagra make you last longer?

The evidence is mixed. Sildenafil (sold as Viagra) is a medicine for erectile dysfunction, and the NHS says research has found that medicines of its type may also help with premature ejaculation. A 2020 review that pooled placebo-controlled trials of these medicines found they lengthened the time to ejaculation by about 2.6 minutes compared with a placebo, but caused more side effects, and its authors say more high-quality trials are needed. In a 2005 trial of sildenafil, the gain in time to ejaculation wasn't statistically significant.

In that placebo-controlled trial in men with premature ejaculation, those taking sildenafil reported more confidence and control, and in one part of the study, at a single centre, had a shorter wait before a second erection. Headache and flushing were the most common side effects. Viagra's product information says it's for adult men with erectile dysfunction, so using it for premature ejaculation alone is a decision for a doctor. The trials are covered in does Viagra make you last longer?

What does morning wood say about your health?

Morning wood is the last of the erections that happen during sleep, as a 2014 history puts it. A 2004 review describes erections during rapid eye movement (REM) sleep as a robust event in all normal healthy males, irrespective of age, though in a 1988 study of 40 healthy men aged 23 to 73 they became less frequent and shorter with age. Because they're involuntary, doctors have used sleep erections to help tell psychological erection problems from physical ones.

The International Society for Sexual Medicine (ISSM) says the lack of a morning erection isn't necessarily a concern, because you may simply wake at a point in your sleep cycle when an erection isn't happening, but that men should mention changes in their morning erections to their healthcare provider. The NHS notes that, depending on the cause, men with erectile dysfunction may still get erections at other times, such as when they wake up. See morning wood: what it says about your health, and our guide to erectile dysfunction.

What happens when a man has an orgasm?

Orgasm and ejaculation are two separate processes that usually happen together. A 2015 review in Fertility and Sterility describes orgasm as an intense, brief peak of pleasure, and ejaculation as two phases: emission, when the fluids that make up semen move into the urethra, and expulsion, when rhythmic muscle contractions push the semen out.

Afterwards comes the refractory period, a temporary pause before another erection or ejaculation, which the review calls poorly understood. More in the male orgasm explained.

How often should a man ejaculate?

We found no NHS or NICE guidance that sets a healthy number. One large study looked at prostate cancer. It followed 31,925 US health professionals from 1992 to 2010: men who reported 21 or more ejaculations a month were less likely to be diagnosed with prostate cancer than men who reported 4 to 7. The men reported their own frequency, and the link was mainly with low-risk cancers.

It's an observational study, so it shows a link rather than proving cause. For couples trying for a baby, NICE says vaginal sex every 2 to 3 days optimises the chance of pregnancy. What this does and doesn't tell you is in how often should a man ejaculate?

How long should foreplay last?

We found no NHS or medical guidance that sets a time. But couples in one study wanted more foreplay than they had. In a study of 152 heterosexual couples by researchers at the University of New Brunswick, both men and women said their ideal foreplay and intercourse would last longer than they actually did, and men and women wanted the same length of foreplay.

The couples reported their own times, and the study is more than 20 years old, so treat it as a starting point for a conversation with a partner. See foreplay: a practical guide.

Why has my sex drive dropped?

A low sex drive has many possible causes, the NHS says. Its list includes relationship problems; stress, anxiety or depression; sexual problems such as erectile dysfunction; some medicines, such as those for high blood pressure and antidepressants; drinking too much alcohol; and long-term conditions such as heart disease, diabetes or an underactive thyroid.

Treating the cause should help, and the NHS says to see a GP if you're worried. The causes are covered in low libido in men: common causes of a low sex drive.

When to get help

The NHS says to get help for these signs:

• Go to A&E or call 999 for sudden, severe pain in a testicle; testicle pain with feeling sick, being sick or tummy pain; or testicle pain that has lasted more than an hour or continues when you're resting.
• Call 999 or go to A&E if your foreskin is pulled back and can't go back over the end of your penis.
• See a GP or go to a sexual health clinic if erection problems keep happening.
• See a GP if you have a persistent problem with ejaculation, swelling or a hard lump on your penis, a penis that curves upwards or downwards when it's erect, or painful erections.