Researchers believe they are closer to knowing why men are unable to go straight to a second round of intercourse after a study ruled out a common excuse for it.
The fact is that even when men want to go again, they need a break before re-starting sexual activity after ejaculating.
Usually, the length of the break required varies by age from around 15 minutes for an 18-year-old to up to 20 hours for a 70-year-old male.
For a long time, it was thought that the reason behind this refractory period was due to the hormone prolactin.
In 2013, a study suggested that high levels of this hormone in men is linked to a lower sex drive and even erectile dysfunction.
However, now a new Portuguese study revealed that prolactin levels have no impact on a mans ability to have sex again straight after orgasm.
Though, it is still thought to have some effect on sexual function and arousal.
In the new study, conducted by the Champalimaud Centre for the Unknown, scientists altered the prolactin levels of mice.
They expected to see a difference in the mice’s ability to have sex again after orgasm, but found that the prolactin levels made no difference.
Corresponding author of the study, Dr Susana Lima said that this means it’s very “unlikely” that the hormone dictates a man’s ability to go again.
The scientist believes that as prolactin has a “central role” in “suppressing male sexual behaviour” then it was thought it must control their ability to have sex a second time.
She told science journal, Nature : “However, a direct link between prolactin and the male post-ejaculatory refractory period was never directly demonstrated.
“Still, this theory has become so widespread that it now appears in textbooks as well as in the popular press.”
Finding out that prolactin is not the reason for the male refractory period after sex means that other theories must now be tested.
Dr Lima added: “Now we can move on and try to find out what’s really happening.”