🤔 Why isn't male birth control a thing?
A brief history of condoms, the pelvic floor gets some love, and all sides of the spermpocalypse debate
📧 Newsletter tl;dr
💁♀️ Who am I: 2x author, 2x boy mom, angel investor, recovering entrepreneur, straight-talking research wonk
📖 Who should read: Fertility/pregnancy enthusiasts and startup fans
🗓 How often will it hit my inbox? 1x/week
🔬 What will it feature: Reproductive health hacks and facts, interviews with experts, startup features, things I love, weird gifs
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This week’s edition is all about male birth control in honor of the research breakthrough announced at Weill Cornell (on-demand male birth control that stopped sperm cold in 30-60 minutes—only tested in mice but very cool).
We’ll start with the condoms origin story straight from the pages of Fertility Rules then on to what makes male birth control so hard and exciting work in the startup world.
Fertility Rules excerpt: A quick history of condoms
Egyptian artwork and cave paintings in France revealed the invention of condoms fifteen thousand years ago. Giacomo Casanova (yes, he was a real person and renowned for womanizing) famously used assurance caps, the predecessor to condoms. Back then, they were used more for avoiding syphilis than contraception and the first versions were like gift wrapping a penis, as they were constructed of linen, soaked in a chemical solution, and tied on with a ribbon. Condoms went through a few iterations before modern versions emerged and were made of everything from lamb intestines, rubber (condoms earned that nickname for a reason!), and animal horn before manufacturers settled on latex. Now they’re made for her pleasure, his pleasure, studded, ribbed, scented, flavored, and coated with CBD. Their job, like all barrier methods, is to physically block sperm from progressing through the cervix. Other options include diaphragms, sponges, cervical caps, and spermicide, and the efficacy of each range between 70 and 88 percent, pending the additional use of spermicide. One bonus of barrier methods is that they all reduce (but do not eliminate) the risk of STDs, especially condoms when used correctly.
And since none of them have lasting effects on the body, there is no impact on fertility—you can get pregnant immediately.
🙋♂️ Why don’t we have better male birth control options?
Because stopping the daily production of millions of sperm every day is hard. Much harder than changing circumstances in the vagina to stop sperm from reaching an egg once per month, or preventing that single egg from ever ovulating. No solutions (so far) are effective enough, nor are they as reversible, affordable, or available as the pill for women. But there is an eager market waiting.
98% of women would trust a committed partner to use male birth control, and over half of men say that if birth control sans side effects were available, they would happily take it. There was also a spike in vasectomy requests after the overturning of Roe v. Wade. Add to that the surge of Gen Z women dropping their hormonal birth control in favor of more natural options and the need has never been bigger.
Scientists have been toiling away at this problem for a while. In the 1950s, a drug called WIN-18446 stopped sperm production in mice. When it was administered to humans, in this case, inmates of an Oregon prison a problem arose. While it completely blocked an enzyme called ALDH that helps produce sperm, it also froze another type of ALDH, which metabolizes alcohol. One test subject made an unfortunately timed choice to consume whiskey while on this treatment and nearly died of alcohol poisoning. In the 1970s, a combination of synthetic testosterone and progesterone was shown to be effective in reducing sperm counts but came with too many side effects—side effects that are, ironically, like those reported with women’s birth control pills.
Now there are birth control injections, transdermal gels, and scientists are attempting reversible reprogramming of sperm to be worse swimmers. Two startups have collectively raised over $40M to tackle male birth control with two very different approaches.
Contraline raised a total of $24.6M for vas-occlusion. Their injectable hydrogel serves as an IUD or sort of temporary vasectomy for men. It is implanted into the vas deferens where it blocks sperm from escaping through a minimally-invasive outpatient procedure and is fully reversible. The company is performing human trials in Australia to prove longevity but right now the hydrogel is thought to last 1-2 years before degrading.
YourChoice raised $16.7M to pursue a male birth control pill. The difference between it and the pill for women is that it is non-hormonal. Its effects are temporary and block cell division and sperm release. So far, trials are limited to animals but results appear to be promising.
What’s the tl;dr?
There is huge, obvious potential in this category, and room for multiple victors. But whoever succeeds has to not only figure out the science; they also have to meet men where they are. And where they are is nowhere near the healthcare system unless an appendage is about to fall off. Volunteering for annual or biannual birth control appointments, a needle approaching their penis, and monitoring to ensure it’s still working seems unlikely.
If the on-demand pill out of Weill Cornell works, or another pill sans side effects is released and easily accessible online, that seems likely to catch on. If a vas occlusion treatment like Contraline’s can be proven to work on a longer time horizon, more like 3-5 years or longer, that is a compelling proposition for men in their early 20s who would otherwise pursue a vasectomy. The longer you wait to reverse a vasectomy, the less likely it is to work, making it a less-than-ideal option for anyone planning to start a family in a decade or more.
📖 What I’m reading
💫 Every woman can benefit from this pelvic floor workout (NY Times)
- Must read by the amazing Danielle Friedman (author of Let’s Get Physical) that delves into why the pelvic floor is so important, and a 6 exercise workout anyone can do
💊 On demand male birth control pill shows promise (StudyFinds) (orig)
- An on-demand non-hormonal birth control pill prevented mouse sperm from maturing for 24 hours with no long-term effects on sexual function🦒 What scientists are learning about women’s health from other female animals (Scientific American)
- Long form read asking the questions can evolved adaptations of other female animals help us solve women’s health challenges?😵💫 Declining sperm counts: much more than you want to know (Astral Codex Ten)
- No matter where you sit on this issue, this is a congent analysis of all sides of the spermpocalypse debate.🍆 Is the human penis getting longer? World Journal Men’s Health
- A worldwide review and meta-analysis of penile length performed by scientists from Emory, Stanford, and three Italian universities says yes, the average penis length increased in the past three decades. Causes: unknown.
⚡️ A random thing that makes my life better
Not an ad, just something I love
If, like me, you own the Apple trifecta (iWatch, iPhone, and begrudgingly, Airpods), you’ve experienced the struggle that is charging. My husband Nick is particularly susceptible to cord management rage. So for our anniversary, I found a bedside table solution: this wireless charging stand from Journey, which charges all three wirelessly, simultaneously, and quickly.
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“So much more than the birds and the bees! Leslie Schrock demystifies human reproduction in her meticulously researched Fertility Rules. Written in a way readers can understand, she breaks down the latest data behind fertility, infertility, and miscarriage. Essential reading for those wanting to understand how their body works, improve chances of conception, and take a deep dive into the facts.”
- Dana McQueen, MD, MAS, Reproductive Endocrinologist