Resources ・ Hormone Therapy

A handbook to testosterone, or 'T'

Foria's clinical team

by Foria Clinical Team

minute read

What is testosterone? Learn about medication types, effects, timelines, things to keep in mind, and how to get started.

On this page

    Share article

    Share on FacebookShare on Twitter

    If you’re looking for information about testosterone, you’re in the right place. Maybe you’re deciding if hormones are right for you, or perhaps you’re already on treatment. Either way, we’re here to help! This article will run through how testosterone works, the types available and changes you can expect from treatment. 

    What is testosterone?

    Testosterone (which some people call “T”) is a drug used in gender-affirming care. It’s a hormone that’s taken by people who were assigned female at birth (AFAB), and can also be taken by intersex people. 

    T produces changes to your body that can better reflect your gender identity and/or expression. These include a deeper voice, facial hair, and more muscle mass. It also has psychological effects - it can change your sex drive and mood.

    Medication types

    If you’re interested in starting testosterone, there’s two options for your medication type. The first is topical testosterone, which comes as a gel you apply every day. The second is an injection taken every one or two weeks, which you administer yourself. Other types of testosterone exist, like an implant under the skin, but they aren’t available in Canada. 

    Topical testosterone

    You can apply T to your skin through a gel. This is usually taken once a day. Topical T can be more expensive if you’re paying out of pocket, but it’s covered by Ontario’s provincial drug plans (if you qualify). In Alberta, compounded gels and creams can be covered by public drug plans on a case by case basis.

    Topical T also gives you more flexibility. For example, if you’re having difficulty with side effects or cost is an issue, you can space your doses out. You can also space doses out if you are aiming for more gradual effects.

    One drawback of topical T is that it can transfer from your skin to other people, like your partner or children, if you’re not careful. Some people choose injectable T instead (see below) to avoid this.

    Applying testosterone gel

    1. Time of day. T gel needs to dry completely before you put on clothes, and you should wait at least two hours before showering, bathing or swimming. Many people find morning works best – that way it won’t rub off onto someone you sleep next to.

    2. Choose your area. The best places to apply T gel are where it will be covered by clothes (so it won’t rub off on anyone else) and where your skin doesn’t bend or rub (so not elbows, armpits or behind your knees). Think upper arm, shoulder or thigh.

    3. Clean and dry. Make sure your skin is clean and dry before applying. If you apply after a shower, you need to dry off completely.

    4. Apply! T gel comes in a pump dispenser or tear-open packet, which you can apply directly to your body or onto your hand before rubbing in. Just dispense the number of pumps as per your prescription.

    5. Wash your hands. This will stop the gel transferring to other people or pets.

    Injectable testosterone

    Injectable T is taken every week or two and you can administer it yourself. It’s cheaper than topical T and it’s covered by the Ontario Drug Benefit program (OHIP+, OW, Trillium, ODSP) and Alberta's public drug program (AISH, Alberta Works), if you qualify. It’s also less demanding on your schedule than daily topical applications. A drawback is that you have less control over your dose, because you are taking larger amounts less frequently. Also, some people don’t like handling needles. You can get someone else, like a loved one or a healthcare professional, to do your injections if you’d prefer.

    There are two options for injecting testosterone: intramuscular injections (i.e. into your muscle) or subcutaneous injections (i.e. into the tissue under your skin). For intramuscular injections you’ll use a longer 22 or 23 gauge needle and inject into your upper buttock or thigh. For subcutaneous you’ll use a shorter 25 or 26 gauge needle and you can inject into your stomach, upper arm, thigh or upper buttock. Both injection methods are equally effective.

    Effects of testosterone

    Testosterone produces multiple changes that can change how your body looks and feels. Everyone responds to T differently – some of these changes can take longer to appear, and some may be more or less intense. Your genetics and lifestyle can also influence them. For example, diet and exercise will affect how much muscle you put on. 

    Lower, deepened voice

    Testosterone can thicken your vocal cords which changes how your voice sounds. For most people on T, your voice will become deeper. This is one of the most noticeable changes from hormone therapy and can help a lot with dysphoria. It may start as quickly as a few weeks into treatment, but for most people it will begin after a few months. As these changes progress you might feel hoarse or have some cracks in your voice. 


    One of the biggest changes from T is the hair on your face and body. Your body hair might get thicker, darker and grow in new places. This can include new pubic hair, which itches as it grows in (no need to worry!). You may also grow new hair on your face. For many people, facial hair can help improve your dysphoria; how much hair you grow will depend a lot on your genetics, though. Some people will develop full beards and some people won’t. 

    It can take a few years to see the full effect of T on your facial hair, so patience is key. It might feel frustrating if you don’t get as much beard growth from treatment as you’d expect, but it can help to remind yourself that your gender is unique! It expands beyond any one physical trait, and you can define it however is meaningful to you.

    Another change from T is hair loss on your scalp. Whether you’ll have hair loss and how much is hard to predict, because it’s largely genetic. If you’re concerned about hair loss then talk to your clinician – there are oral or topical medications that can help.  

    Body composition

    Testosterone can change where fat is stored on your body. Over time, you might notice that there’s less fat on your face, hips and thighs. T can also cause more fat to store in your belly. These changes can start within the first few months of treatment and they can help change your gender presentation.

    T can also help you gain more lean muscle mass, which you can maximize with resistance training (i.e. lifting weights) and changes to your diet. It’s important to remember, though, that this doesn’t happen overnight. Be kind to your body and your mind, and don’t worry if your changes don’t match up to someone else’s timeline. 

    Genital changes

    Testosterone can cause your clitoris and clitoral hood to grow longer and wider (often called “bottom growth”). The amount that it will grow varies, but it can be up to 4 cm in length. As your clitoris grows, you might experience some pain or sensitivity. It might also feel different during sex (in a good way!) and get hard when you’re aroused. Bottom growth can start as soon as a few weeks on T, but it can also take a few months.

    T can also cause vaginal dryness and atrophy, which means your vagina or front hole lubricates less and its walls become thinner. This can make small tears more likely if you have penetrative sex. Lube can help with this, and there’s also topical treatments your clinician can prescribe. These release small amounts of estrogen into the tissues of the area, but don’t worry – it’s not enough to affect your hormone therapy.

    Your periods will also get lighter on treatment and for most people should eventually stop. The timeline of this will depend on how heavy your periods were before starting hormones. See our fertility section for more info about contraception and family planning.

    Mood and sex drive

    Along with physical changes, testosterone can affect how you think and feel. Gender-affirming care as a whole can improve depression, anxiety and self-esteem as you become more comfortable. However, T specifically can cause mood changes. For example, you might find that you’re more short-tempered than before. If you have any pre-existing mental health conditions it can affect these too. Before starting treatment, talk to your clinician about your mental health history and they can help you monitor any changes in mood.

    One common effect of T is that your sex drive changes. It can boost your libido and, along with changing your body, can change the kind of sex you’re into. You might also notice a change in who you’re attracted to. Communicating openly with any partners you may have can help you figure out what works best for you.


    One of the quickest effects of testosterone is changes to your skin. It might become more oily and thicker within a few weeks, and some people develop acne. This can usually be treated with over-the-counter products and often resolves by itself, but if it becomes difficult then talk to your clinician. There are some prescription treatments available for severe cases.

    Timeline of changes

    If you have friends on T or read transition diaries online, they might tell you when certain changes will happen. It can feel frustrating if your progress doesn’t match someone else’s timeline, but don’t worry! There’s a fairly wide range in when changes can start and when they reach their maximum effect. Based on information from Rainbow Health Ontario, this is when these can happen for most people:

    ChangesOnsetMaximum effect
    Skin oiliness/acne1-6 months1-2 years
    Vaginal atrophy1-6 months1-2 years
    Body fat redistribution1-6 months2-5 years
    Periods stopping1-6 monthsUnknown
    Clitoral growth (“bottom growth”)1-6 months1-2 years
    Facial/body hair growth3-6 months4-5 years
    Scalp hair loss6-12 monthsVariable
    Increased muscle mass/strength6-12 months2-5 years
    Deepened voice6-12 months1-2 years

    Verified answerPermanent vs temporary changes

    Some changes from T, like your mood or body composition, are temporary. This means that if you stop treatment they will eventually reverse.

    Other changes like facial hair, bottom growth and a deeper voice are permanent. This means you can stop treatment and they will remain.

    Some people choose to stop T after reaching permanent changes that they’re happy with, while others will continue for the rest of their lives. You can decide whatever works best for you and your body – and remember, you can adjust your treatment at any time.


    Everyone’s gender is unique. Just like there’s no one way to be trans, there’s no one dose for testosterone. You can work with your clinician to figure out what works best for you, based on the physical and mental effects you’d like to see from treatment. 

    Starting dose

    When you start testosterone, your clinician may prescribe a low dose and increase this over time. If your goal is a higher dose, you’ll work your way up to this. The speed depends on how you respond to treatment and any side effects you’re having. The maximum dose will put your T levels in the normal range for someone assigned male at birth. 

    In your first year of treatment you’ll be monitored at 1, 3, 6 and 12 months. You will have your blood taken to check your hormone levels and monitor other things like kidney function. After your first year of treatment, you’ll only need your hormone levels checked once a year.

    Increasing or lowering dose

    You can adjust your dose at any time. Increasing your dose can intensify the changes T makes to your body. Reducing your dose can help if you’re having undesirable side effects. It’s important to remember, though, that adjusting dose won’t reverse permanent changes like a deeper voice.


    Some people will stay at lower doses for more gradual physical effects (often known as “microdosing”). This is generally easier with topical T, because you have more control over your dose. Microdosing can slow down the pace of changes but it won’t change which ones are temporary or permanent. If you’d like to microdose your hormones, you can discuss this with your clinician at your planning appointments.

    Stopping hormones

    Not all trans, non-binary and gender-diverse people stay on hormone therapy, and there’s many reasons you might stop treatment. Maybe you’re having side effects, or maybe you want to become pregnant or start fertility treatments. Some people also stop T because they’re happy with the permanent changes they’ve had. 

    Some people might feel guilt or shame about stopping treatment. It’s important to know that hormone therapy doesn’t define you – whatever your treatment journey is, your gender and your experience are valid. At Foria, we’ll support whatever treatment path you decide to take. It can be scary to talk to your clinician about stopping hormones, but it’s essential to make sure you’re doing it safely. For example, you may need to start other medications if you’ve removed your uterus and ovaries. 

    If you’ve stopped hormones for non-medical reasons, you can start again at any time. Your treatment plan when you restart will depend on your previous experience with T.

    Verified answerDetransitioning

    A small number of people choose to stop treatment permanently, and this is sometimes known as "detransition" or "retransition". This can happen even if someone’s had positive outcomes from treatment. There can be many reasons for detransitioning, like mental health challenges, discrimination, or a change in how someone experiences their gender. Detransition doesn’t always include feelings of regret. In fact, researchers who study gender-affirming care have found that many people who detransition don’t regret their experiences of treatment. 

    Things to look out for

    Long-term studies show that testosterone for gender-affirming care is safe and has low health risks. The main health risks with T relate to your cardiovascular system (so changes in cholesterol levels, higher blood pressure and sleep apnea). A lot of factors can determine if you will have side effects, including lifestyle and genetics.

    The cardiovascular risk from T may be in the range of someone assigned male at birth, but research isn’t completely clear yet. Either way, your clinician will monitor your health and can adjust your treatment if needed. The good news is that most health-related side effects can be reversed by stopping treatment. 


    If you’re planning for pregnancy in the future, it’s a good idea to talk to your clinician before you start hormone therapy. This is because testosterone can reduce your fertility, making it harder to get pregnant. Freezing eggs or embryos before starting treatment can give you more options when it comes to family planning.

    If you’ve already started testosterone and would like to become pregnant, then you can pause your treatment. Research shows that your periods can resume after going off hormones for a few months, which allows you to become pregnant or preserve your eggs/embryos.

    Although testosterone can reduce fertility, it’s not a contraceptive. This means it’s possible to get pregnant while you’re on T. However, hormone therapy is not safe while pregnant and you may not be able to continue a pregnancy that began while you were on it. If you haven’t had a hysterectomy and your sex partner produces sperm, talk to your clinician about what contraceptives are best for you.

    Getting started with testosterone

    Interested in starting testosterone? Foria’s clinicians can guide you through your options when it comes to gender-affirming care. If hormone therapy is right for you, they can work with you to build a treatment plan that reflects your goals. If you’re re-starting testosterone we can also guide you through this, and we can transfer your care if you’re already on treatment but would like to use Foria.

    If you'd like to learn more about Foria's hormone therapy program, visit our testosterone service page.

    This content has been reviewed by Foria’s Medical Director, Dr. Kate Greenaway and our community advisory team. Medical sources include Rainbow Health Ontario’s Guidelines for Gender-Affirming Primary Care with Trans and Non-Binary Patients, Fenway Health, San Francisco AIDS Foundation and the UCSF Transgender Care & Treatment Guidelines.

    Foria's clinical team

    by Foria Clinical Team

    minute read

    Share article

    Share on FacebookShare on Twitter