This article is part of a series on the impacts of hormone replacement therapy (HRT).

During transition, many people are eager for hormonal changes to take place rapidly- understandably so. But it's very important to remember that the extent of these changes, and the rate at which the changes take place, depend on many factors. These factors include your genetics, the age at which you start taking hormones, and your overall state of health.

Click here to read this full article, written by Dr. Maddie Deutsch, Associate Professor of Clinical Family & Community Medicine at the University of California – San Francisco (UCSF), and Medical Director for UCSF Transgender Care.

What kinds of physical changes can you expect, and when should you expect to see them?

Your skin will become a bit thicker and more oily.
You may develop acne, which in some cases can be bothersome or severe, but usually can be managed with good skin care practices and common acne treatments.
Your chest will not change much in response to testosterone therapy.
Your body will begin to redistribute your weight. Fat will diminish somewhat around your hips and thighs.
Your eyes and face will begin to develop a more angular, “masculine” appearance as facial fat decreases and shifts.
Your muscle mass and strength will increase, although this will depend on various factors, including diet and exercise.
Testosterone will cause a thickening of the vocal cords, which will result in a more “male-sounding” voice.
The hair on your body (including your chest, back, and arms) will likely increase in thickness, become darker, and grow faster.
Most people who take testosterone notice some degree of frontal scalp hair thinning, especially in the area of your temples. How much hair loss you experience will depend on your age and family history.
Regarding facial hair, some people develop a thick beard quite rapidly, others take several years, while some never develop a full, thick beard.
Lastly, you may notice changes in your perception of the senses. For example, when you touch things, they may “feel different,” and you may perceive pain and temperature differently.

If you parent a gender-expansive youth, some of these changes may seem unexpected or uncomfortable. Be assured that most physical changes happen slowly— sometimes slower than the young person in your life may want them to!

You may want to read our post about starting hormones to get a better sense of the many guardrails in place to protect your young person from making any permanent decisions they are not ready to consent to.