Contraceptive pills for women include popular choices such as cerazette, marvelon, yasmin and zoely, all of which slightly differ in their active ingredients and mechanism of action, but all are ultimately designed to prevent the woman from becoming pregnant. For the male, there is the barrier method of wearing a condom, which some men still find uncomfortable doing, and not much else choice wise. However, could things change in the future? Remarkably, there may be contraceptive pill on the horizon that could be taken by both men and women, following advancements in the knowledge of sperm biology in the United States. The new study, funded by the governmental National Institutes of Health, could also lead to the reversal of infertility in thousands of British men after the findings demonstrated how sperm are given a “power boost” to get to the egg. The scientists involved in the study managed to identify a protein contained in sperm that provides it with sufficient energy it requires to power towards an egg and break into it. Researchers in the study commented that this ABHD2 protein allows the tail to ‘crack like a whip’ and ‘power kick’ its way into the egg. With this in mind, by blocking this protein, this could stop the sperm from fertilising the egg. Dr Stuart Moss, of the National Institutes of Health, said: “Developing new compounds that block ABHD2 ultimately may yield new contraceptive methods that prevent sperm from research the egg.” University of California, Berkeley researcher Melissa Miller also commented: “What is really cool is that we have an actual target for unisex contraceptive development.” Therefore theoretically, a contraception pill could be taken by either the male or female, which could let men have a bigger share of the contraceptive responsibility in a relationship. On the flip side, a pill which boosts the protein could even help infertile couples to finally have children, the journal Science reports. At the moment, around 80% of male infertility cases cannot be pinpointed to a definitive reason, mainly because doctors are not fully aware how the interactions between sperm and eggs result in infertility. Moreover, the sperm could be the problem in half of all cases of infertile couples. It was previously challenging to analyse the functions of sperm with conventional laboratory methods due to the fact it is the body's smallest cell. However, advancements in technology over the last 5 years led to the new discovery at the University of California, whereby scientists have been able to attach electrodes to the sperm's tail and record how it reacts to hormones. This meant that they were able to discover how a large receptor on the sperm tails - a calcium channel referred to as CatSper - is activated by progesterone from the egg. The scientists however believed that the progesterone wasn’t directly impacting on the calcium channel, but on another receptor, which then activated the calcium channel. This was found to be true; tests showing that progesterone binds to an enzyme named ABHD2, found in abundance within sperm. After it connects to the enzyme – on the surface of the sperm - it get rids of a lipid that has been inhibiting the calcium channel. This then allows CatSper to open the gate to calcium ions and thus, sperm activation. Ms Miller commented that this inhibitor, CatSper, is probably there to stop the sperm from prematurely travelling to the egg and using up their limited supply of energy.