Study Finds Sperm Quality Deteriorates Across Species During Storage

Researchers at Oxford University say regular ejaculation can boost male fertility

Mar. 25, 2026 at 11:14am

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A new study led by Oxford University researchers suggests that regular ejaculation - whether through sexual activity or masturbation - results in higher quality sperm, with less DNA damage. The findings are based on a major, cross-species analysis which revealed a shared pattern across many animals, from insects to mammals, where sperm that is stored (whether in males or females) deteriorates rapidly - resulting in reduced sperm performance, fertilization success, and embryo quality.

Why it matters

The study's findings have immediate implications for clinical practice, as they suggest the upper limit of 7 days of abstinence in World Health Organization guidelines may be too long. The results also provide insights that could benefit captive breeding programs for endangered species and deepen our understanding of how species evolved mechanisms to reduce sperm damage during storage.

The details

The researchers carried out a meta-analysis of 115 human studies (involving 54,889 men) and 56 studies across 30 non-human species. This confirmed that mature sperm in storage generally deteriorates in quality independently of the age of the male - a process called post-meiotic sperm senescence. In humans, longer periods of sexual abstinence were associated with increased sperm DNA damage and oxidative stress, along with reduced sperm motility and viability.

  • The study was published on March 25, 2026.

The players

Dr. Rebecca Dean

Co-lead author and researcher in the Department of Biology at the University of Oxford.

Dr. Irem Sepil

Senior author and researcher in the Department of Biology at the University of Oxford.

Dr. Krish Sanghvi

Lead author and researcher in the Department of Biology at the University of Oxford.

World Health Organization (WHO)

The global health agency that provides guidelines on semen sample collection and assisted reproduction.

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What they’re saying

“Because sperm are highly mobile and have minimal cytoplasm, they quickly exhaust their stored energy reserves and have limited capacity for repair. This makes storage particularly damaging compared to other types of cells. Our study highlights how regular ejaculation can provide a small but meaningful boost to male fertility.”

— Dr. Rebecca Dean, Co-lead author

“This likely reflects the evolution of female-specific adaptations, such as specialised storage organs that provide antioxidants to extend sperm viability. These organs often secrete reproductive fluids to nourish sperm and could provide unexplored avenues for biomimicking technology to improve artificial sperm storage in the future.”

— Dr. Irem Sepil, Senior author

“Ejaculates should be viewed as populations of individual sperm which undergo birth, death, ageing and selective mortality. The rates of these demographic processes can differ in males and females, mediating the 'demographic' structure of sperm populations and sex-specific differences in sperm storage effects.”

— Dr. Krish Sanghvi, Lead author

What’s next

The researchers plan to further investigate the mechanisms behind sperm deterioration during storage and explore potential ways to mimic female-specific adaptations to improve artificial sperm storage techniques.

The takeaway

This study challenges long-held assumptions about sperm storage and provides new insights that could significantly impact clinical practice in fertility treatments, as well as conservation efforts for endangered species. By bridging the gap between biomedical and zoological research, it offers a fresh perspective on the complex dynamics of reproduction.