Gender-affirming hormone therapy (GAHT) is associated with significantly improved HIV outcomes for transgender, nonbinary, and other gender-diverse (trans) people in the U.S., according to a new study published in The Lancet HIV.

The study, part of the LEGACY cohort, which analyzed data from more than 8,000 trans patients receiving care at federally qualified health centers, found that compared to trans patients not prescribed GAHT, patients prescribed GAHT had a 37% reduced risk of acquiring HIV, and a 44% lower risk of viral non-suppression (where levels of the virus in the blood are high and can lead to disease progression and HIV transmission to others) for those living with HIV.

In the U.S., trans people (who have a gender identity that differs from the sex assigned to them at birth) have higher rates of HIV and worse HIV treatment outcomes compared to cisgender people, including higher viral non-suppression rates. Previous research has found that GAHT is medically necessary for many trans people and is thought to improve health outcomes. However, few studies have assessed the association between GAHT and HIV acquisition in trans individuals.

The study highlights disparities in HIV rates among racial and ethnic minority groups, with Black, Latinx, and multiracial trans people experiencing disproportionately high rates of HIV, which may be linked to structural barriers in health care access, such as having lower socioeconomic status or living in poverty.

The study also found low rates of pre-exposure prophylaxis (PrEP) uptake in the cohort, which the authors say represents another future intervention target to reduce HIV rates, and that integrating GAHT with services such as PrEP and HIV treatment may help to further reduce transmission rates and improve health outcomes for trans people in the U.S.

These findings support the evidence for the medical use of GAHT in trans adults and call for expanded access to gender-affirming care as part of national HIV prevention and treatment strategies.

In an accompanying Viewpoint, also published in The Lancet HIV, the authors outline the Situated Vulnerabilities and Resiliencies Framework, which explores why trans people face high rates of HIV and what could be done to address these inequalities. The authors suggest that trans people have a higher risk of contracting HIV due to various social, economic, and health care barriers, including high rates of mental health conditions, exposure to sexual violence, economic instability, homelessness, and systemic oppression.

Their Framework calls for solutions beyond medical treatment, including legal protections, community support, and improved access to gender-affirming care. It also emphasizes the importance of working directly with trans communities to create effective and inclusive HIV prevention and care programs.

The authors call for more research and funding into research for trans people living with HIV, especially in regions outside of North America and Europe, and to ensure that all trans people have access to appropriate health care.