Europe is struggling with low birth rates. They wouldn’t do it here, as is right now it’s already a calamity.
But yes, if they said something is 100% effective and it wasn’t, I would imagine they would be sued into bankruptcy pretty fast.
How much would an accidental child cost these days?
That said this is still great news especially as the condom is also much less safe then the female contraceptive pill.
We only have the numbers for the lab environment with I assume perfect use for this new drug, so we can only compare perfect use.
I don't know if they mean 99% reduction compared to normal or 99% of mice did not cause a pregnancy. Either way this does not mean that every intercourse has a 1% chance of causing a pregnancy. Also you are assuming an unconditional probability. It could very well be a conditional probability. It might completely work for 99% that do not cause any pregnancies at all and not work for 1% that cause pregnancies as without the drug.
Anyway I am looking forward to getting the perl index for humans from clinical trials.
Edit: fixed wrong wording
Birth control effectiveness is measured by calculating the number of pregnancies per 100 women using a specific method for a full calendar year.
https://www.who.int/news-room/fact-sheets/detail/family-plan...
>Effectiveness of methods is measured by the number of pregnancies per 100 women using the method per year.
Example: Silodosin.
You need to experiment with it. Sensitive clinical trials measured rates as high as 90-99%.
It is entirely non-hormonal. It does not affect libido (rarely), while hormonal male contraceptives do, and it is reversible upon cessation, without any delay, unlike hormonal male contraceptives.
It may be confusing, so to clarify: "seminal fluids" is a term typically used to refer to the fluid released during ejaculation, not throughout the arousal phase. The idea that sperm would be in the mix before the emission phase goes against standard reproductive physiology.
Sperm are only actively introduced into seminal fluid during the emission phase of ejaculation; the so-called "grand finale." :D. Before that, in the arousal phase, the fluids released (like pre-ejaculate) typically contain no sperm unless there's residual contamination from a previous ejaculation.
(And FWIW, if one might wonder: thankfully this "residual contamination" poses no health risk or birth defects.)
If semen isn't ejaculated, the body reabsorbs the sperm in the epididymis and recycles the cellular material. Seminal fluids, which are produced during arousal, are either reabsorbed or, in cases like retrograde ejaculation (e.g., with alpha-blockers), pass into the bladder and are later urinated out. The system self-regulates; there's no harmful buildup to worry about. :)
So, TL;DR: You will just urinate it out in our case.
Fantasy, meditation, hypnosis, Kegel exercises... They could lead to orgasms and sometimes even ejaculation (which would be bad in this case).
Some medications rarely may cause spontaneous orgasms, even, without physical contact, arousal or stimulation.
Plus the thing does not stop the drip so you do have to pull out sooner rather than later or else. It does not stop sperm production.
Also dry ones tend to result. They're sometimes uncomfortable.
Tamsulosin is I believe the modern one but all of them are for long term. Probably least side effects.
Otherwise if taken as a single dose fresh, side effects like orthostatic hypotension are vastly increased.
You're right that it doesn't stop sperm production, just emission. As for "the drip"; that's pre-ejaculate, which doesn't contain sperm inherently, but can pick up residual sperm in the urethra from a prior ejaculation.
And that's true, anejaculatory orgasms can feel strange or less satisfying for some, but it is not universal.
> Otherwise if taken as a single dose fresh, side effects like orthostatic hypotension are vastly increased.
That is true.
This is in the same range as, like, pulling out, for what it's worth.
Or am I misunderstanding what you're proposing with "universal"?
Great recurring source of revenue for the drug company!
Though I'm more interested in feral animals like dogs. It looks like this drug may work on dogs too? If so, it would be a huge boon for cities and villages in India.
Taking outside sources of testosterone permanently alters your body's ability to make testosterone naturally, to the extent that many people who previously took steroids find they have be on testosterone therapy for the rest of their lives.
I wouldn't call "creating a lifelong requirement to take artificial hormones in order to function at your previous baseline" qualifying as "no particularly good reason".
>Ever since that study, testosterone has undergone extensive clinical trials as a hormonal method of male contraception and many have found testosterone to be efficacious, reversible and safe with minimal short-term side effects
https://pmc.ncbi.nlm.nih.gov/articles/PMC6305868/
It's not super reliable but it's also easily testable if it's working or not.
https://www.discovermagazine.com/health/the-myth-of-roid-rag...
"Testosterone as a contraceptive can suppress spermatogenesis and lead to azoospermia in 65% of normospermic men within 4 months of use"
Does this sound like a convenient and effective contraceptive? Where are you really coming from with this statement?
Most women would never do this, but a few definitely would.
birth-control pills (male or female) are powerless against sexually-transmissible diseases.
Long-term safety seems doubtful. Offspring could be affected. In a rational world there would be no volunteers for the trials.
https://www.nature.com/articles/s43856-025-00752-7
> YCT-529 works by interfering with vitamin A signaling necessary for sperm production and fertility.
> The importance of dietary vitamin A and retinoid signaling for male germ cell development and differentiation has been recognized for many years6. All trans-retinoic acid (Fig. 1a) is an active metabolite of vitamin A that exerts its function, at least partly, by binding to retinoic acid receptors (RARs). The RARs α, β, and γ, are encoded by the Rara, Rarb, and Rarg genes in mice, and Rarα and Rarγ have been validated as contraceptive targets by genetic knockouts resulting in male sterility7,8. Notably, the effects on spermatogenesis in the absence of RARα most resemble the loss of RAR signaling in vitamin A deficiency, and the mice are otherwise normal7,8. Further, the effects on spermatogenesis in animals treated orally with the dual RARα/RARγ antagonist BMS-189453 (Fig. 1a, b) closely phenocopied the absence of RARα function. Importantly, the resulting male sterility is reversible9,10,11. We, therefore, wished to identify RARα−selective inhibitors for potential male non-hormonal contraception. Our study describes the development of YCT-529, a highly selective RARα antagonist that reduces sperm counts in mice and non-human primates. Mating studies with male mice treated with 10 mg/kg/day for 4 weeks show that YCT-529 is 99% effective in preventing pregnancies and that the mice fully regain fertility after drug cessation.
gnabgib•1h ago