Testosterone Enanthate Vaccine Interaction Profile

What the label's drug interactions section covers

The intramuscular testosterone enanthate label lists four interacting drugs or drug groups: oral anticoagulants, antidiabetic drugs and insulin, ACTH and corticosteroids, and oxyphenbutazone [1]. For oral anticoagulants it says patients need close monitoring, especially when androgens are started or stopped [1]. With antidiabetic drugs and insulin, androgens may lower blood glucose and insulin requirements [1]. With ACTH and corticosteroids the label describes an enhanced tendency toward edema and advises caution, especially in patients with liver or heart disease [1]. Serum oxyphenbutazone levels may rise [1].

The contraindications section names breast cancer, known or suspected prostate cancer, pregnancy, and hypersensitivity to any component of the product [1].

What is known about testosterone and vaccine response

Reviews of vaccine immunology find that females typically develop higher antibody responses and more adverse events after vaccination than males [2]. A 2025 review of sexual immune dimorphism describes testosterone as having primarily immunosuppressive effects, while estrogen enhances immune activation [4]. A 2018 study found that male mice lacking the androgen receptor had more splenic B cells and higher serum BAFF, and that healthy men with low testosterone had higher serum BAFF [3]. These findings concern sex differences and B-cell biology. They do not measure antibody titers in men receiving testosterone enanthate injections.