The mission towards male birth control

With great pleasure comes great responsibility. Five thousand years ago, fish bladders served as a common contraceptive sheath. A few millennia later, we progressed to vaginal dams made of lint, honey, and acacia leaves (some species of which are toxic). Attempting to shirk the inevitable responsibilities of reproduction has lead us ambitiously through bizarre trials, errors and tricky contraceptive dice rolls. Fortunately, in the last century, nurse and female health activist Margaret Sanger pioneered the first birth control clinic in the United States (and did time for it). Undeterred, Sanger kept opening clinics. Eventually, a court ruling in her favour had the Comstock Act, which outlawed advertisements, information and sale of contraceptives, overturned. Condoms, diaphragms (then called womb veils) became available – as did more helpful information. Sanger fought well into her 80s, underwriting much of the research for oral female birth control, drummed up $150,000 worth of funding in 1950 (that's about 1.5 million dollars in buying power today) and convinced biologist Goodwin Pincus to make it happen. In the '60s, we got the pill.     

It's proven indispensable as pharmaceutical tech for increasing reproductive agency, but for sixty years women have had to shoulder the burden of biochemical birth control subjecting their bodies to a host of potential side effects. Family obstetrician and regular medical expert on The Goods, Dr Melissa Lem confirms that the pill is generally quite safe but those side effects can range from "mood changes, breast tenderness and bloating" to more serious ones including things like "liver dysfunction and life-threatening blood clots." Women may be on the verge of enjoying a reprieve from these risks altogether thanks to a heart-stopping toxin. It's called ouabain and it also happens to stop sperm, or at least slow them down enough to keep them from getting anywhere fruitful. Enter men.

Widely used on arrow tips by traditional hunting societies in Africa to increase kill success, ouabain affects transporter proteins that allow sodium and potassium ions to pass through cell membranes. Some of those proteins are found in cardiac tissue, making it a fine choice for poisoned arrows aimed at stopping hearts. But researchers at the University of Minnesota (in collaboration with numerous academic institutions worldwide) have been exploiting the poisonous effect of ouabain for a decade now because it's also been shown to cling to and disrupt a transporter known as 𝜶4 found only in one place: mature sperm cells. Thanks to recent research, a synthetic version of the toxin that leaves the heart undisturbed but focuses instead on sperm function already exists.

If the idea of a toxin attaching itself to your sperm or those of someone you love leaves you a little leery, consider botox. It's a neurotoxic protein derived from botulinum and nobody's angry about that anymore – not that you could tell if their scowl lines had been recently been touched up. Still, researchers have tested their synthetic contraceptive compound in rats. Not only are the male rat subjects doing just fine, but they aren't getting any female rats pregnant.

The real boon here, say researchers, is the way the contraception takes place and fertility gets interrupted. Treatment interferes with sperm mobility – once chemically bound to the 𝜶4 transporter cells – mature sperm (and only mature sperm) can't swim, making them unable to get anywhere near an egg and completely useless as fertilizing agents. But because only mature sperm take the toxic hit, all sperm cells produced after getting off the male pill will likely prove to be fine swimmers. Ultimately, the hope in humans is that the effects will be entirely reversible and far less invasive than a vasectomy (which, gentle reminder, still involves a couple of syringes into both testicles and a minor day surgery). No big deal, but also, no small deal, however safe and correctable. Suffice to say, I and many other men may favour the option of a pill, a touch of toxins be damned.

For women who may be concerned about their own reproductive organs coming into contact with sperm that have been slowed down via a toxin, Dr Lem posits that because of the altered toxin's tendency to adhere specifically the 𝜶4 transporter in sperm cells, "it's unlikely it would cause any significant effects in women who are exposed to affected sperm – especially in the small doses transmitted through sexual contact." Hopefully, the research team will see to those female rats to be sure.      

Naturally, this isn't the first time male birth control has been explored (conversely, do recall the female condom). There are already hormonal versions of a male birth control pill in the works that would mirror current contraception pills for women. The pill, as we know it, tweaks hormones like estrogen and progesterone with the synthetic hormone progestin to halt ovulation in spite of inevitable biological processes and despite the presence of any active sperm swimming within egg proximity. Dr. Lem confirms that it actually functions like something of a mind game. "The birth control pill," she says "tricks your brain into thinking that you've already ovulated, because estrogen and progesterone peak around ovulation. This shuts down the feedback loop and hormone cascade that leads to an egg maturing and being released."

The masculine answer to that being testosterone and progesterone getting tweaked to interrupt the biological mechanism of spermatogenesis (active and fertile sperm production). It's essentially a chemical vasectomy. Like the pill, there are numerous potential side-effects. Fluctuations in weight or libido are expected as are marked mood swings and depression. A hormonal pill for men also lowers their good cholesterol (HDL-C), something less ideal for long-term heart health. Other long-term effects are bound to remain nebulous until men start taking them. Human trials are already underway, which means the hormonal pill will likely hit pharmacies before the ouabain-inspired version. It's certainly progress but the researchers in the non-hormonal camp say that a toxin-derived pill may offer far fewer side effects and arguably offer a safer alternative.

Some stats put male-directed contraception options at about 30% (mostly via condoms and vasectomies), with the remaining responsibility landing on women. A new pill aimed at safely and temporarily curbing the reproductive viability of masculine organs may decrease the load for women by increasing birth control options for men from the big three of condom, vasectomy and abstinence to a fourth, and favourable one.

I, for one, am just deeply content that we've at least moved past fish bladders.