Could testosterone therapy cause male pattern baldness?

Yes: Testosterone is broken down in body into dihydrotestosterone (DHT) and estrodiol (E2). Excess T is converted into DHT & E2 above & beyond baseline level. Excess DHT is linked to hair loss such that we use 5ARIs to reduce DHT. Prime examples of 5ARI is Finasteride (Propecia (finasteride) or Proscar). However, lowering DHT can sometimes increase E2, leading to loss of libido, erectile dysfunction & gynecomastia