Vasalgel™ - The next male contraceptive?

_{By RJA1988 on pixabay.com}

Implants, IUDs, shots, vaginal rings, patches, pills, condoms (male and female), diaphragms, sponges, cervical caps, spermicide, fertility awareness, pull out, breastfeeding, tubal ligation, vasectomy, and abstinence¹. The list of available birth control is long, but not every method is that effective (abstinence didn’t work for the Virgin Mary) and some aren’t reversible, which causes many doctors to refuse to do them, especially in the case of women (“At one point, your biological clock will start ticking, and then you will THANK me!”).

The problem is, most of these methods are for women, not men. And many of the available female contraceptives are hormonal. I myself am using a hormonal contraceptive, which puts me at a higher risk for thromboembolism, stroke, myocardial infarction, breast cancer², … the list goes on.

Knowing how hormones work, it doesn’t surprise me. If you put something in your body that’s supposed to have a particular effect, there will be side effects. That occurs even with food! Biology and chemistry aren’t something focused on a goal, it’s all statistics in the end. That’s why one person can deal well with the flu, and someone else might die despite being initially healthy. That’s why medication doesn’t work the same for everybody.

Wouldn’t it be better to switch to non-hormonal then?

Well, I’d love to. But condoms can break, and the other methods aren’t as effective. And besides, shouldn’t men have something more reliable too? But they also don’t want to be pumped full of hormones …

Maybe some of you have heard about it before (I’ve read it online a few years ago, but forgot about it again until yesterday), but there’s a non-hormonal, male contraceptive in development. Actually, there’s two.

First, there was RISUG® (stands for Reversible Inhibition of Sperm Under Guidance), which was developed and is being studied in India. It’s styrene-maleic anhydride, which is injected into the vas deferens (which is a duct that transports sperm from the epididymis to the ejaculatory ducts) and is supposed to change the pH, which damages the sperm and prevents it from moving normally.
So far, RISUG® is not officially on the market, despite being tested for a while now³. Additionally, reversal of this process has so far only been tested in animals, not human test subjects⁴. In case you were already planning to fly to India and get this injection, you might now want to wait a bit with that. _@suesa

After RISUG®, the Parsemus Foundation in the USA started developing Vasalgel™. A quote from their homepage reads:

VasalgelTM is a long-acting, nonhormonal contraceptive with a significant advantage over vasectomy: it is likely to be more reversible.

… likely? That’s not as encouraging as some of you might have hoped. Why do they only say likely?

They can’t claim yet that it’s working in humans, because clinical trials are supposed to start this year (2018), provided they have enough funding ⁴. But the animal experiments look good so far.

In contrary to RISUG®, Vasalgel™ is styrene-alt-maleic acid, not an anhydride. Anhydrides are possibly less stable when in contact with water, which in an environment like the human body isn’t too unlikely. The lack of anhydrides is supposed to make Vasalgel™ more stable. It’s also injected into the vas deferens, but instead of damaging the sperm, it forms a blockage, preventing it from exiting⁵. This does not mean no ejaculation happens! The fluid just doesn’t contain sperm⁴.

They successfully tested this in male (…obviously) rabbits. Before adding the Vasalgel™, they established a baseline for the amount of sperm found in the ejaculate. Aside from some exceptions where the animals turned out oligospermic ( = they had semen with a low concentration of sperm, which is likely not enough to impregnate a female), the test animals exhibited an azoospermia (= no sperm in semen) after 29-36 days, which was still effective 12 months later⁵.

The injections tested were actually two different ones, 100% the acid and an 80:20 mix of acid-anhydride.

_{figure 1 Sperm concentration during baseline and implant conditions for the two test articles.
This image is licensed under a CC Attribution 4.0 International License. © Waller et al., 2016}

As you can see in the figure above, there was no real difference between the two injections.

14 months after the injection, the researchers used sodium bicarbonate to flush the Vasalgel out and reverse the effect. After that, the sperm count was initially higher than the baseline (figure 2), likely due to full reserves. Soon, it reached normal levels again⁶.

_{figure 2 Sperm concentration (x 106) during baseline and following reversal procedures
This image is licensed under a CC Attribution 4.0 International License. © Waller et al., 2017}

Mobility also returned to normal, while forward progression was lower, but improved over time, suggesting that after enough recovery time, this too would return to normal⁶.

Now, rabbits are great and all, but how do we know that this might work in humans?

It was tested on monkeys (rhesus macaque monkeys to be specific) of course³! Getting a permit to do that is a lot harder than to test on rabbits and mice, just so you know, at least in Germany.

The monkeys were, just as the rabbit, put under anesthesia and had an operation to introduce Vasalgel™ into their vas deferens. They were then put back with a group of fertile females, allowing them to … try to reproduce. In which they failed, to their dismay and the joy of the researchers! The contraceptive had worked, which allows Vasalgel™ to move on to the clinical studies in humans³.

And when can we expect this to happen?

Clinical studies take time and cost money. The Parsemus Foundation appears to be relying on donations to secure their funding⁴, and if you think about it, it should come to no surprise. A one-time injection is far less profitable than have someone buy a monthly supply of pills or a pack of expensive condoms. Additionally, Parsemus claims that they want to make the injection “available close to cost in low-income countries, and affordable to those in every income level in the U.S.” ⁴.

Sounds promising! But we will see how it progresses.

What do you think? Is it time for something like this to hit the market? Would you do it yourself? This is something I’m really curious about because many men already complain about using a condom. Would you undergo a (reversible) surgical procedure to avoid impregnating someone on accident? Or should your partner be responsible for taking the pill?

Also, please keep in mind that this contraception only prevents pregnancies. To protect yourself from STDs, you’d still need to use a condom. Personally, I’d see it more as double insurance, but would you still consider it “worth it”? Or is it only something for when you’re in a long-term relationship where you know your partner is STD-free and you’re not using a condom?

Let me know!

---

Sources:

¹Birth Control

²Benefits and risks of hormonal contraception for women

³The contraceptive efficacy of intravas injection of Vasalgel™ for adult male rhesus monkeys

⁴Vasalgel - Parsemus Foundation

⁵Azoospermia in rabbits following an intravas injection of Vasalgel ™

⁶Reversibility of Vasalgel™ male contraceptive in a rabbit model

---

_{GIF was created for me by @saywha and @atopy , rest of the signature by @overkillcoin}