The Next Generation of Male Contraceptives

Published on: 

One company reaches beyond traditionally-conceived male contraceptives with Vasalgel, a reversible hydrogel injectable.

In today’s political climate, contraceptives are often top-of-mind for many adults in child-bearing years. NEXT Life Sciences—a company developing and distributing contraceptives—pursues the regulatory approval of a new type of contraceptive in the United States for individuals assigned male at birth. This medical device, Vasalgel, is currently in preclinical studies.

According to the NEXT Life Sciences’ website, “Vasalgel is a proprietary hydrogel injected into the vas deferens (the tube that sperm swim through). The procedure differs from a vasectomy in that the vas is not cut or cauterized. Instead, a hydrogel is injected with a microneedle, and once formed in place, the hydrogel is intended to act as a flexible filter for sperm. The ultimate goal is for the product to be easily removed by injecting with a microneedle a fluid that dissolves and flushes out the hydrogel whenever a man wishes to restore the flow of sperm” (1).

According to Robert S. Kellar, PhD, chief science officer, NEXT Life Sciences, Vasalgel was inspired by the research of Dr. Sujoy Guha in India in the 1970s, who created this technology to address increasing resource strain due to overpopulation in India (2). In India, this technology is called RISUG (reversible inhibition of sperm under guidance).

Administration of Vasalgel

What is the process of administration for Vasalgel? In short, with a relatively quick procedure, a liquid solution is injected by a professional and solidifies into a flexible sperm filter that creates a barrier.

“The medical procedure is intended to be minimally invasive and to be less painful than a traditional vasectomy, allowing for a faster recovery time,” explained Kellar. “The clinician will apply a local anesthetic, then expose the vas deferens from the testicular sac. The injection of Vasalgel will then occur into the lumen of the vas deferens. Vasalgel will hydrolyze from a viscous state to a hydrogel form, which creates a blockage in the lumen of the vas without cutting or burning tissue. Vasalgel will adhere to the vas deferens walls, preventing sperm cells from passing through. For the patient, the recovery time will be faster with less post-procedural swelling and discomfort compared to traditional vasectomy.”

Effectiveness, efficacy, and reversibility of Vasalgel

Aaron Tabor, PhD, chief technology officer, NEXT Life Sciences, explained that a stable polymer is created via a chemical interaction that forms a hydrogel.

“While formal stability testing is underway, preclinical studies have demonstrated blockage,” said Tabor. “Predecessors using similar formulations to RISUG have reported more than 13 years of effectiveness. Once cleared or approved for humans, it should be possible for the male to have Vasalgel implanted and removed multiple times.”


“Based on the chemistry for the hydrogel formation, an alkaline solution can dissolve the hydrogel, which allows for sperm cells to begin traveling through the vas deferens lumen. One can have the hydrogel injected with such a solution to result in [the] dissolution of the blockage,” added Tabor. Vasalgel would, therefore, be reversible.

According to a 2020 article in Basic Clin Androl., RISUG was introduced in successful preclinical trials starting in 1980 and achieved success in human volunteers in Phase I, II, and III clinical trials in India (2).

Development hurdles and getting FDA approval

“To date, Vasalgel has demonstrated effectiveness in many of the preclinical models. This allows NEXT Life Sciences to confidently state we have ‘proof of concept’ on the Vasalgel technology,” said Kellar. “We are now optimizing the formulation to allow for the scale up of manufacturing. This optimizedVasalgel ensures reliable safety and efficacy expectations in preclinical models and will enable working with regulatory bodies on our proposed strategy for clinical implementation.”

NEXT Life Sciences intends to use the medical device 510(k) pathway for Vasalgel technology clearance, Kellar explained, adding that regulatory focus will be on the revisability of hydrogel, including the return of sperm cells in the ejaculate.

While there has been considerable delay in bringing Vasalgel (or other devices and drugs like it) to the US market, it could be theorized that current public attention on contraceptive methods may positively impact the regulatory review, though only time will tell.

What’s next for Vasalgel, particularly as it relates to development and potential commercial manufacturing? Tabor explains that the company is presently creating its final formulation as well as vetting contract development and manufacturing organizations that can “scale manufacturing with the regulatory approval efforts.” The company is also building its medical and scientific advisory boards with experts in the field of contraception.

Vasagel’s potential for female contraception

This technology also has the potential to be used as a contraceptive for individuals assigned female at birth.

“Hypothetically, Vasalgel could be used as a female contraceptive option,” said Tabor. “This technology could be modified for female oocyte blockage—thus, preventing the ability for sperm-and-egg fertilization. While some preclinical testing has occurred, more work would need to be completed, such as further bench-top assessment, preclinical testing, and, of course, human regulatory pathways.”

Breakthroughs in male contraceptives and areas for improvement

“Outside of equality being brought to the attention of male contraceptives, the greatest breakthrough is a grouping of minimally invasive procedures that potentially prevent irreversible damage to the vas deferens. This includes occlusive technologies such as ligation clips, silicone plugs, and hydrogel technologies, such as Vasalgel. These platforms hypothetically prevent sperm from entering the female reproductive anatomy, offering reversible or removable male contraceptives,” said Kellar.

However, the industry still has improvements to be made in order to ensure that safe contraceptives for males are readily available. Kellar identifies a few key areas, some of which relate specifically to Vasalgel:

  • Clearly understood delivery paths. How will men learn about contraceptive options? There isn’t currently a standard in the US for this education as there is for women, who are educated on contraceptive options by a gynecologist (pending access to medical care).
  • Insurance reimbursement and coverage. At present, whether Vasalgel will be covered by insurance is yet to be determined. Meanwhile, some contraceptives for women are currently covered by medical insurance plans.

Technologies such as Vasalgel and RISUG could usher a new generation of contraceptives available to individuals of child-bearing years and provide more family-planning options. The legal, political, and cultural climate suggests alternatives to traditional approaches may find ready acceptance for this unmet medical need.


1. NEXT Life Sciences, “Vasalgel,” (accessed Sept. 2022).

2. B. Khilwani et al., Basic Clin Androl., DOI:10.1186/s12610-020-0099-1 (2020).

About the author

Meg Rivers is the former senior editor for Pharmaceutical Technology, Pharmaceutical Technology Europe, and BioPharm International.