Factors associated with the informal use of HIV pre-exposure prophylaxis in Germany: a cross-sectional study.

Informal PrEP use was associated with a higher risk of not getting tested before and during PrEP use, which could lead to HIV infections resistant to tenofovir and emtricitabine if people with undiagnosed HIV use PrEP. Health insurance plans that cover PrEP and the accompanying routine tests could ensure adequate medical supervision of PrEP users and reduce barriers to PrEP use. Our findings strongly support the implementation of PrEP programmes in countries with similar patterns of informal PrEP use.