Scientists have edged one step closer to creating a male pill, new research suggests.

Thirty hours after infusing male macaques with a compound known as EP055, their sperm were unable to move, a study found.

Lead author Dr Michael O'Rand, from the University of North Carolina, said: 'Simply put, the compound turns-off the sperm's ability to swim, significantly limiting fertilization capabilities.'

None of the monkeys suffered side effects, which is thought to be due to EP055 having no effect on male hormones, according to the researchers.

Most female birth-control pills contain a mix of the hormones oestrogen and progesterone, which can cause weight gain, erratic moods and nausea.

In addition, all of the monkeys' sperm were moving as normal within three weeks, suggesting the treatment is reversible, the research adds.

Currently, male contraception is largely limited to condoms, which can fail up to 18 percent of the time if worn incorrectly, or vasectomies, which are expensive and difficult to reverse.

Scientists have edged one step closer to creating a male 'pill', new research suggests (stock)

DOES HORMONAL BIRTH CONTROL INCREASE A WOMAN'S RISK OF DEPRESSION? Hormonal birth control does not increase women's risk of depression, research suggested in February 2017. Contrary to popular belief, contraceptive pills, implants or injections do not make women more likely to suffer from the mental-health condition, a study found. Lead author Dr Brett Worly from Ohio State University, said: 'Depression is a concern for a lot of women when they're starting hormonal contraception. 'Based on our findings, this side effect shouldn't be a concern for most women, and they should feel comfortable knowing they're making a safe choice.' The researchers blame platforms such as social media for making contraception complications seem more common than they are. Dr Worly said: 'We live in a media-savvy age where if one or a few people have severe side effects, all of a sudden, that gets amplified to every single person. 'The biggest misconception is that birth control leads to depression. For most patients that's just not the case.' The scientists add, however, certain women are at a greater risk of the mental-health disorder and should be monitored closely. Dr Worly said: 'Adolescents will sometimes have a higher risk of depression, not necessarily because of the medicine they're taking, but because they have that risk to start with. 'For those patients, it's important that they have a good relationship with their healthcare provider so they can get the appropriate screening done - regardless of the medications they're on.' The researchers reviewed thousands of studies investigating the link between contraceptives and people's mental health. Such studies included various methods of contraception, including injections, implants and pills. Participants in the trials were made up of teenagers, women with a history of depression and those who had given birth in the past six weeks. Advertisement

Complete recovery after 18 days

EP055 binds to the protein EPPIN, which is present on surface of sperm.

Within six hours of infusion, the monkeys' sperm mobility was reduced by around 20 percent.

Speaking of the findings, study author Dr Mary Zelinski added: 'At 18 days post-infusion, all macaques showed signs of complete recovery, suggesting that the EP055 compound is indeed reversible.'

Sperm mobility began to improve after around three days.

The researchers add it is unclear when the contraception may be available for human use.

They are testing EP055 in pill form and plan to investigate it effectiveness at preventing pregnancy in an animal study.

How the research was carried out

The scientists infused four male macaques with a 75-80mg/kg dose of EP055.

After a recovery period, they then administered a 125-130mg/kg dose.

The findings were published in the journal PLOS ONE.

Birth-control pills increase women's risk of stroke

This comes after research released last month suggested oral contraceptives increase women's risk of stroke.

Birth-control pills raise a woman's likelihood of suffering from an ischemic stroke, which occurs when an artery to the brain is blocked and makes up around 85 percent of cases of the life-threatening condition, a study found.

The researchers, from Loyola University, Chicago, wrote: '[Among] women with other stroke risk factors, the risk seems higher and, in most cases, oral contraceptive use should be discouraged'.

Such contraceptives do not raise the risk of hemorrhagic strokes, which are caused by bleeding in the brain, the research adds.

Birth-control pills, patches and jabs are thought to rise the risk of artery blockages by making blood more likely to clot.

The researchers stress, however, the risk is low among women without any risk factors for clotting, such as high-blood pressure and smoking.

Most women have tried at least one hormonal contraceptive in their lives. In the US, nearly 37 percent of women are currently using birth control.

Stroke is the third leading cause of death in women in the US, with 55,000 more females suffering than men every year.