New Bill Gates-Funded Injection Could Offer Years of Birth Control In Single Shot
A new innovation in injectable medicine, developed by MIT engineers and funded by the Bill & Melinda Gates Foundation, is poised to revolutionize long-term contraception and potentially the treatment of chronic diseases. This new technology uses a novel drug delivery method that could provide effective contraception — and potentially other treatments — for years following a single injection.
Tiny Crystals, Big Potential
At the heart of this breakthrough is a system that suspends tiny drug crystals in a biocompatible solvent. When injected under the skin, the solvent allows the crystals to self-assemble into a compact “depot,” a solid structure that remains in place and gradually releases medication over time. Unlike current long-acting injectables that often disperse throughout tissues and degrade relatively quickly, this depot stays localized, offering a controlled, steady drug release for months — and potentially years — without the need for frequent re-administration.
The solvent used, benzyl benzoate, has a well-established safety profile and helps in creating the initial fluidity necessary for injection. Once inside the body, the solvent’s poor miscibility with biological fluids causes the drug crystals to aggregate into a durable mass.
According to lead researcher Giovanni Traverso, an associate professor at MIT, “We showed that we can have very controlled, sustained delivery, likely for multiple months and even years through a small needle.”
Easier, Less Invasive Administration
One of the most notable advantages of this new technology is its ease of use. Traditional long-acting contraceptive methods, such as hormonal implants or intrauterine devices (IUDs), often require surgical procedures or large-bore needles for implantation, which can be a barrier to widespread adoption, especially in low-resource settings.
In contrast, this new crystal-based injectable can be administered through a fine-gauge needle, similar to those used for standard vaccinations. This makes it significantly less invasive and easier for healthcare workers to deploy, even in rural or underserved areas where access to sophisticated medical facilities is limited.
The Gates Foundation, a long-time advocate for improving global health, particularly women’s reproductive health, funded the project with the goal of expanding contraceptive options globally. “The overarching goal is to give women access to a lot of different formats for contraception that are easy to administer, compatible with being used in the developing world, and have a range of different timeframes of durations of action,” said Vivian Feig, one of the study’s lead authors.
Strong Preclinical Results
Initial animal studies have shown remarkable promise. Researchers injected the formulation into rats and monitored the depot’s stability and drug release. After three months, approximately 85% of the drug remained within the depot, indicating a very slow and steady release profile that could theoretically last well beyond a year.
These early results suggest that the injectable could offer far longer-lasting contraception than currently available options such as Depo-Provera, which requires re-administration every three months. Moreover, because the depot remains compact under the skin, it can be surgically removed if the patient decides to terminate treatment early — a flexibility not available with many other long-acting formulations.
Applications Beyond Contraception
While the initial focus has been on contraceptive use, researchers are optimistic about broader applications. The technology could be adapted for the long-term delivery of drugs to treat diseases such as HIV, tuberculosis, and even neuropsychiatric disorders that require consistent medication levels over extended periods.
The ability to customize the drug release rate adds to its versatility. By adjusting the density of the depot — for instance, by adding a small amount of biodegradable polymer — researchers can fine-tune how quickly or slowly the drug is released.
“By incorporating a very small amount of polymers — less than 1.6 percent by weight — we can modulate the drug release rate, extending its duration while maintaining injectability,” said Sanghyun Park, a co-author of the study. “This demonstrates the tunability of our system, which can be engineered to accommodate a broader range of contraceptive needs as well as tailored dosing regimens for other therapeutic applications.”
Next Steps: Moving Toward Human Trials
With these promising preclinical results in hand, the MIT team is now working on advancing the technology toward human testing. Further studies will focus on validating the depot’s formation and stability in a human skin environment, as well as confirming long-term safety and effectiveness.
“This is a very simple system — it’s basically a solvent, the drug, and then you can add a little bit of bioresorbable polymer,” Traverso said. “Now we’re considering which indications do we go after: Is it contraception? Is it others? These are some of the things that we’re starting to look into as part of the next steps toward translation to humans.”
The project’s funding has come from several sources beyond the Gates Foundation, including the Karl van Tassel Career Development Professorship, the MIT Department of Mechanical Engineering, and additional fellowships such as the Schmidt Science Fellows program and the Rhodes Trust.
If successful in human trials, this technology could reshape the landscape of global healthcare, providing long-term, low-maintenance treatment options for millions — with a simple, minimally invasive injection.