No, women’s bodies don’t ‘store’ DNA from all male sexual partners forever

We probably all have exes we would rather forget, but a recent viral post suggests we may be genetically connected forever. 

"Women store DNA from every man they’ve ever made love with, study finds. Scientists discover that women harvest all male DNA," a Jan 15. Instagram post’s headline read. The post garnered over 5,700 likes in just 18 hours and was reposted by other accounts. 

Behind the headline is a collage of bright images, including a heat map and X-ray of couples kissing, a sperm and egg, and a photo suggesting that a child’s DNA can be made up of DNA from multiple different sexual partners. 

The post’s featured headline came from the website "Neon Nettle" which we have fact-checked several times. FactCheck.org also includes in its list of websites that post deceptive content. 

(Screenshot from Instagram)

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There is no evidence from legitimate news sources or published medical research to support the claim that women are storing DNA from all their sexual partners. The claim misrepresents the findings of a study that examined small amounts of male DNA present in some female brains. It stated that this phenomenon is most likely caused by a pregnancy with a male child. 

This claim first went viral back in 2017. Fact-checkers at the Australian Associated Press traced it back to an article titled "Women absorb and retain DNA from every man they have sex with," published by "YourNewsWire" a frequent publisher of misinformation. 

The 2017 article, as well as the Neon Nettle article featured in the 2024 Instagram post, cite as evidence a 2012 study from the University of Seattle and the Fred Hutchinson Cancer Research Center. 

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The study in question was examining "male microchimerism" in the female brain. Chimerism is when DNA from one person appears in another person’s body. It has many causes including medical treatments such as blood transfusions or transplants of stem cells or bone marrow. Chimerism can also happen in twins, when one embryo dies in the womb and the surviving fetus absorbs some of the deceased embryo’s cells. 

This small-scale DNA swapping also occurs during pregnancy between a mother and a fetus. 

The 2012 study tested the autopsied brains of 59 women and found 63% of them had male microchimerism present. "The most likely source" of this DNA in women’s brains, the study said, is "from pregnancy with a male fetus." 

For women without sons, this male microchimerism could have also resulted from an abortion or a miscarriage — some women can even miscarry without realizing they were pregnant. The study mentioned other possible sources including a "vanished male twin," an older brother or a blood transfusion. 

The study does not cite sexual intercourse as a possible source of the DNA.  

Male microchimerism can occur in women without sons; a 2005 study of 120 women detected it in 21%. This older study poses sexual intercourse as a possibility, as does a 2016 Danish study, but neither study investigated that theory in depth and both suggested other alternatives for the DNA’s presence, including a blood transfusion during pregnancy.

"Any suggestion that male DNA is routinely retained from sexual partners has no support from any scientific study," Dr. J. Lee Nelson, an autoimmunity researcher and rheumatologist said in a 2018 interview with Business Insider. Nelson is a professor at the Fred Hutchinson Cancer Center and was involved in both the 2012 and 2005 studies. 

Nelson also noted in the interview that if this long-term DNA transfer did occur through sex, researchers would have likely detected it in the vast majority of women. They didn’t. Plus sperm lasts only about five days in the woman’s reproductive tract.

The post’s claim that women "store DNA" from all their male sexual partners is based on a flawed interpretation of a scientific study of male DNA in female brains. The study concluded that male DNA’s presence in some female brains likely resulted from a pregnancy with a male child. It did not mention sexual intercourse as a cause. 

This claim has been repeatedly shared on sites that spread misinformation, and experts say there are no scientific studies to support the conclusion that women retain DNA from all their sexual partners. We rate this claim False.