To the Editor I would like to offer 2 points to expand on the important analysis by Sarkar and colleagues.¹ First, use of a single prostate-specific antigen (PSA) multiplier for all men using 5α-reductase inhibitors (5-ARIs) is probably not optimal. The goal is to estimate what each man’s PSA would have been in the absence of drug treatment. However, because 5-ARIs inhibit the common age-associated increase in gland volume and PSA, the PSA trajectory for a man being treated with a drug vs his counterfactual trajectory with no drug diverge over time. Furthermore, the benign prostatic hyperplasia component of total PSA would be higher in an older man vs a younger one. Therefore, a larger multiplier may be optimal in older men with longer-term 5-ARI exposure to further avoid delayed diagnosis. Alternatively, men taking 5-ARIs could benefit from monitoring with newer biomarkers that are less sensitive to alterations in androgen levels, such as urinary PCA3 or ERG fusion assays.