5ARD or 17B HSD (a.k.a. 5 Alpha Reductase Deficiency Syndrome or 17 Beta Hydroxysteroid Dehydrogenase deficiency)

As a guy with 5ARD or 17 beta HSD, your body developed gonads called testes, but the testes either didn’t make testosterone (T), and/or another type of more powerful T called DHT, when you were growing. As a result your penis may not have grown much at that time. However, at puberty, your body is able to make some T that can help your body grow as a guy and help the penis develop.

Since you have a Y chromosome, you won’t have a womb or a period.


To go into puberty, your body will start to make T to help your body grow and develop as a guy. Your doctor might even recommend taking some of the hormone T, if your levels are low.

In the Puberty: Outside section, check out the changes your body makes with T. Depending on your body and if there is conversion of T to E, there also might be some slight changes from E as well, so check out those, too.

Also, some guys with 5ARD or 17Beta HSD may have a small penis and something called a urogenital sinus (a UG sinus) is when a vagina-like pocket – sometimes called a prostatic utricle – and the urethra join together inside the body. Some guys with these conditions might have a very small UG sinus. It just depends. If this is the case, your urologist can help you understand your body. When it comes to any treatments or procedures involving your genitals, remember that these types of treatments are optional, and you are the most important person to decide in all of this!

Gonads: Staying or Going?

As a teen, your body can start to make some T, but still no DHT. Your body may make a little estrogen (E) in some cases.

In the Puberty: Outside section, this means your body will grow and respond to T. It’s hard to know exactly how your body will change, but usually the genitals will grow larger and the body will respond to T (for example, some might grow some facial hair and have the voice deepen). When you go back, check out what happens when your body reacts mostly to T. Talk to your doctor more about what to expect.

Thinking about these changes and what to do can be really hard. During puberty, your mind changes a lot, as does how you feel about yourself. When thinking about hormones with parents and doctors, check out this page again.

These discussions are big ones to have with your family and doctors. Some doctors talk about puberty blockers—medicine that keeps your gonads from growing and making T & E. This can temporarily stop your puberty and give you some time to decide what you would like to do.*

Talking to your doctors, a psychologist, or even people who have gone through the same thing can be really helpful. After all, this stuff is complicated. It is important to find someone who will hear your thoughts and help you understand your many options.

* Note: Feel free to go back to the section about Puberty and the changes that happen in your brain and mind, especially when thinking on what hormones your body needs. Hormones help each body develop into adulthood. Right now, it is important that you have the right hormones for your body. To help with this, your medical team and parents can help you think about what hormones are right for you and your body. If you have 5ARD or 17Beta HSD and are considering whether you want to go into a female or male puberty, please talk to your doctor. There are even some hormones (called puberty blockers) that can block puberty to give you more time to decide what path you want to take.