The US Department of Defense has introduced mandatory testosterone deficiency screening for all active-duty and reserve male service members aged 30 and over, with the clinical guidance taking effect immediately. The policy follows Defense Secretary Pete Hegseth's July announcement that troops would be screened to ensure they had "the right testosterone levels" to perform at their best, framed as part of a broader push on long-term service member health and military readiness. Some endocrinologists have criticised the move, arguing there is insufficient evidence that universal testing improves readiness and warning it could lead to unnecessary or harmful treatment.

Under the new rules, men aged 30 and above must undergo testosterone blood tests, while younger men are only tested if they request it or clinicians spot warning signs; those with low levels may get further evaluation and, where appropriate, voluntary hormone replacement therapy. Women will not face routine testosterone testing but will be screened for fatigue and menstrual disruption linked to hormonal issues, with new guidelines on prescribing off-label testosterone, particularly for postmenopausal women with low libido. Non-medical testosterone use, including for performance enhancement, remains banned. The FDA is due to meet experts later this month to discuss testosterone's medical use.