News | Non-hormonal male contraceptive shows 99% efficacy with no side effects in mouse experiments
At the American Chemical Society (ACS) Spring 2022 meeting, a research team from the University of Minnesota announced that they had developed a non-hormonal oral male contraceptive that demonstrated extremely high contraceptive efficacy (99%) with no obvious side effects in mouse experiments. The achievement is expected to provide men with a reversible, safe, hormone-independent new contraceptive option, reducing the long-term burden of contraceptive responsibility on women.
Current male contraceptive options are limited, and contraceptive responsibility is imbalanced
Although women have a variety of contraceptive options available, such as oral contraceptives, patches, and intrauterine devices, men's current contraceptive options are still limited to condoms and vasectomy surgery. The former carries the risk of user error or failure, while the latter is considered a permanent sterilization method that is irreversible or has an extremely low reversal rate. This lack of options has led to women bearing the long-term "sole responsibility" for contraception.
Non-hormonal pathway: new hope for avoiding side effects
"Scientists have been trying for decades to develop an effective oral contraceptive for men, but there is still no approved product," said Md Abdullah Al Noman, a doctoral student at the University of Minnesota College of Pharmacy and one of the project leaders, at the meeting. Most male contraceptives currently in clinical trials target sex hormones such as testosterone, but these drugs are often accompanied by side effects such as weight gain, depression, and elevated low-density lipoprotein (LDL) cholesterol.
"We wanted to develop a non-hormonal male contraceptive to avoid these side effects," Noman said.
Targeting the RAR-alpha protein to precisely inhibit fertility
The research team focused on a protein called retinoic acid receptor alpha (RAR-alpha). RAR-alpha is one of three retinoic acid receptors. Retinoic acid, a form of vitamin A, plays an important role in cell growth, differentiation (including spermatogenesis), and embryonic development. Previous studies have found that knocking out the RAR-alpha gene in male mice leads to infertility but with no obvious health effects.
The team further analyzed the crystal structure differences in how RAR-alpha and its family receptors RAR-beta and RAR-gamma bind retinoic acid, and screened and synthesized approximately 100 candidate compounds. Ultimately, they identified a compound named YCT529, which inhibits RAR-alpha nearly 500 times more effectively than RAR-beta and RAR-gamma, demonstrating extremely strong selectivity.
In mouse experiments, after male mice were given YCT529 orally for four consecutive weeks, their sperm count decreased significantly, and the contraceptive success rate reached 99% in mating experiments, with no visible side effects observed during the treatment period. More importantly, 4 to 6 weeks after discontinuing the drug, the mice's fertility fully recovered, indicating that this method has good reversibility.
Human clinical trials expected to begin within the year
According to Dr. Gunda Georg of the University of Minnesota College of Pharmacy, one of the project leaders, YCT529 is expected to enter human clinical trials in the third or fourth quarter of 2022. "Although the animal experiment results are encouraging, the translation to human efficacy still carries uncertainty," Georg said. To this end, the team is also actively exploring next-generation drug candidates, either by optimizing the structures of existing compounds or developing entirely new scaffolds, to further improve efficacy and safety.
The research team hopes that their work can break through the technical bottlenecks that have long hindered the market availability of oral contraceptives for men and promote greater equality in global contraceptive responsibility.
Story source:
Collected from the internet
Author LinkedIVF TeamPublished 2025-09-16
This article used AI assistance; LinkedIVF has not recorded an editorial review for this item. It is not medical advice.
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News | Nonhormonal Male Contraceptive Was 99% Effective Without Side Effects in Mice
News | Non-hormonal male contraceptive shows 99% efficacy with no side effects in mouse experiments
At the American Chemical Society (ACS) Spring 2022 meeting, a research team from the University of Minnesota announced that they had developed a non-hormonal oral male contraceptive that demonstrated extremely high contraceptive efficacy (99%) with no obvious side effects in mouse experiments. The achievement is expected to provide men with a reversible, safe, hormone-independent new contraceptive option, reducing the long-term burden of contraceptive responsibility on women.
Current male contraceptive options are limited, and contraceptive responsibility is imbalanced
Although women have a variety of contraceptive options available, such as oral contraceptives, patches, and intrauterine devices, men's current contraceptive options are still limited to condoms and vasectomy surgery. The former carries the risk of user error or failure, while the latter is considered a permanent sterilization method that is irreversible or has an extremely low reversal rate. This lack of options has led to women bearing the long-term "sole responsibility" for contraception.
Non-hormonal pathway: new hope for avoiding side effects
"Scientists have been trying for decades to develop an effective oral contraceptive for men, but there is still no approved product," said Md Abdullah Al Noman, a doctoral student at the University of Minnesota College of Pharmacy and one of the project leaders, at the meeting. Most male contraceptives currently in clinical trials target sex hormones such as testosterone, but these drugs are often accompanied by side effects such as weight gain, depression, and elevated low-density lipoprotein (LDL) cholesterol.
"We wanted to develop a non-hormonal male contraceptive to avoid these side effects," Noman said.
Targeting the RAR-alpha protein to precisely inhibit fertility
The research team focused on a protein called retinoic acid receptor alpha (RAR-alpha). RAR-alpha is one of three retinoic acid receptors. Retinoic acid, a form of vitamin A, plays an important role in cell growth, differentiation (including spermatogenesis), and embryonic development. Previous studies have found that knocking out the RAR-alpha gene in male mice leads to infertility but with no obvious health effects.
The team further analyzed the crystal structure differences in how RAR-alpha and its family receptors RAR-beta and RAR-gamma bind retinoic acid, and screened and synthesized approximately 100 candidate compounds. Ultimately, they identified a compound named YCT529, which inhibits RAR-alpha nearly 500 times more effectively than RAR-beta and RAR-gamma, demonstrating extremely strong selectivity.
Mouse experiments: oral administration for 4 weeks achieves 99% contraceptive efficacy
In mouse experiments, after male mice were given YCT529 orally for four consecutive weeks, their sperm count decreased significantly, and the contraceptive success rate reached 99% in mating experiments, with no visible side effects observed during the treatment period. More importantly, 4 to 6 weeks after discontinuing the drug, the mice's fertility fully recovered, indicating that this method has good reversibility.
Human clinical trials expected to begin within the year
According to Dr. Gunda Georg of the University of Minnesota College of Pharmacy, one of the project leaders, YCT529 is expected to enter human clinical trials in the third or fourth quarter of 2022. "Although the animal experiment results are encouraging, the translation to human efficacy still carries uncertainty," Georg said. To this end, the team is also actively exploring next-generation drug candidates, either by optimizing the structures of existing compounds or developing entirely new scaffolds, to further improve efficacy and safety.
The research team hopes that their work can break through the technical bottlenecks that have long hindered the market availability of oral contraceptives for men and promote greater equality in global contraceptive responsibility.
Story source:
Collected from the internet