The Pentagon is reinstituting a mandatory testing program for testosterone deficiency among US service members age 30 and older, a spokesperson said on Thursday, bringing back a program that medical experts have described as unnecessary and potentially harmful.

The latest clinical guidance applies only to male service members, establishing uniform screening and treatment pathways for testosterone deficiency. The Pentagon said it will issue separate guidance for female service members at a later date.

Medical ​professionals have warned that testosterone, if prescribed inappropriately, could increase service members’ risk of infertility or lead to other health consequences. The Pentagon temporarily rescinded an earlier version of the guidance in early September “to allow for updates,” and it was not immediately clear what changes had been made.

The new guidance calls for testosterone testing as part of periodic health assessments and annual physical examinations, with younger service members able to be screened on request or when clinically indicated.

“Effective immediately, this guidance addresses male testosterone deficiency, establishing uniform screening and treatment pathways,” Pentagon spokesperson Sean Parnell said in a statement.

US Defense Secretary Pete Hegseth, who has promoted the use of ​testosterone to improve military readiness, first announced the screening mandate in July. Under the prior guidance, women were also set to be screened through a questionnaire and could then move to treatment for conditions related to hormonal imbalances.

The new approach comes amid changes in the US Food and Drug Administration’s position on testosterone therapy in men. Last year, the agency removed the boxed warning about increased cardiovascular risk from testosterone products for ​men after reviewing post-marketing studies, though the products still carry warnings about increased blood pressure.

In June, the FDA asked manufacturers to remove labeling that said the safety and efficacy of testosterone replacement had not been established for men with age-related hypogonadism, following a review of newer evidence. Testosterone products remain FDA-approved for men with low testosterone associated with an underlying medical condition.

No FDA-approved testosterone product exists for women. Medical groups generally recommend testosterone for women primarily to treat persistently low sexual desire related to menopause, and say evidence is insufficient for broader uses such as improving energy, cognition or muscle mass.