It’s a very big word for something that can lead to a very big problem. Because it’s a word that comes up often in the discussion of hair loss. Usually, dihydrotestosterone is shortened to the three letter abbreviation DHT. It’s a male hormone that’s believed to play an important role in causing hair loss. If you’re seeking a permanent solution to thinning hair or hair loss, there’s a very good chance you’ve heard of DHT. But you may be wondering what it is and how it is connected to the science of hair loss.