These are rats — 4 weeks of treatment in diet-induced obese animals. Nothing below is a finding about a person, and 4 weeks in a rodent is not a year in a human being.
What makes the study worth reading anyway is a control group most studies skip. [1]
The arm that does the work
Every question about these drugs runs into the same confound: the people taking them are also losing weight, and weight loss changes almost everything you might want to measure.
A pair-fed control settles it. One group gets the drug; a second group is fed exactly the amount the first group chose to eat, so it loses the same weight with no drug in it. Anything that differs between those two arms is the molecule. Anything they share is the eating.
That is the design human studies almost never manage, which is why so much of this field cannot separate the two — the same trouble behind measurements taken on a shrinking body.
What separated, and which way
In male rats, both the drug and the matched restriction improved sperm motility and mucus penetration. That shared result points at the weight rather than the molecule.
The hormones went the other way. Restriction lowered androgens, and semaglutide attenuated that fall — so here the drug partly offset something the weight loss caused.
In females, progesterone, pregnenolone and estradiol fell in a treatment-specific way, meaning the diet alone did not do it. Folliculogenesis increased in both arms. Pituitary hormones shifted in both sexes.
What the receptor count does and does not say
GLP-1 receptor expression measured 4-fold higher in testes than in ovaries — a ratio of 4.0 between two tissues in the same animals. The authors describe this as supporting a potential male bias for the drug’s potency.
Expression is not potency. A tissue can carry many receptors and respond little, or few and respond strongly, and this study did not test the link. Keep it as the hedge they wrote it as, the way a marker close to the mechanism still has to be shown to move.
What nobody measured
Whether any animal conceived. The morphology is described as largely suggesting increased fertility, which is a statement about tissue under a microscope.
In humans the direct evidence remains thin in both directions — small and narrow on the male side, as a twenty-five-man comparison shows, and almost absent for anything a rodent can only gesture at. Animal work of this quality tells you which human study to run. It does not substitute for one, any more than ninety-two more days in mice settles anything about a lifespan.