Tests to measure testosterone levels are primarily offered as blood-based sample collection. (Goldman et al., 2017) Patients reported a definite preference for saliva collection when choosing between oral, urine, and blood samples. Testing saliva is less invasive, and research shows that participation in testing is increased for this option. (Dhima et al., 2013)
Goldman, A. L., Bhasin, S., Wu, F. C. W., Krishna, M., Matsumoto, A. M., & Jasuja, R. (2017). A Reappraisal of Testosterone’s Binding in Circulation: Physiological and Clinical Implications. Endocrine reviews, 38(4), 302–324. https://doi.org/10.1210/er.2017-00025
Dhima, M., Salinas, T. J., Wermers, R. A., Weaver, A. L., & Koka, S. (2013). Preference changes of adult outpatients for giving saliva, urine and blood for clinical testing after actual sample collection. Journal of prosthodontic research, 57(1), 51–56. https://doi.org/10.1016/j.jpor.2012.09.004