Study summary

An mRNA injection restored sperm production in infertile mice

mRNA in mice · Mouse study, Osaka and Baylor · Published October 2025, PNAS

55%of sperm-making tubules took up the mRNA

What was tested

Mice lacking a gene needed to make sperm (Pdha2) were given that gene's mRNA, packed in lipid nanoparticles like those in mRNA vaccines, injected into the testis.

What they found

Sperm appeared within three weeks of one injection.
That sperm produced healthy, fertile pups through IVF-style injection into eggs.
The mRNA lasted about five days and no changes to the animals' DNA were seen.
It treats one specific genetic cause. Each gene would need its own version.

What it means

The clearest route yet to treating men whose azoospermia comes from a single faulty gene, without altering DNA. No human trial has been announced.

PNAS paper ↗ ← Back to the outlook

Last reviewed 2026-11-14 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.