Information About Testosterone

NOTE: This information is compiled from several sources readily available on the internet as identified below.

When considering gender affirming medications, it is important to learn about the risks, expectations, and long-term considerations associated with transition from estrogen/progesterone to more testosterone in the body.

DISCLAIMER: The information contained herein is for informational purposes only and is not intended to substitute for medical advice or constitute medical advice. The information contained herein does not create a health care provider-patient relationship between the reader and any of the authors. The information contained herein is not intended to be definitive or exhaustive, and is compiled from sources believed to be accurate, but the authors make no representation that it is accurate. Moreover, the authors and their agents make no warranties or guarantees, express or implied, concerning the accuracy or appropriateness of this information for any particular reader given the frequent changes in the practice of medicine as new information is learned through medical studies. Readers should consult with a knowledgable healthcare provider for medical advice, treatment, and additional information on gender affirming care options based on their specific health care needs and medical history.

For more information on potential risks, expectations and other long term considerations, please consult “WPATHSOC8, S43 - S79,”Standards of Care for Health of Transgender and Gender Diverse People, Version 8, by E. Coleman, et al., available at: https://www.tandfonline.com/doi/pdf/10.1080/26895269.2022.2100644.[1]

All About Testosterone

It is very important to remember that everyone is different, and that the extent that anyone's body changes and how quickly it happens, depend on many factors. These factors include genetics, the age at which someone starts taking hormones, and their overall state of health. (For more information see:[2]Seattle Children’s Gender Clinic, “A Guide to Gender Affirming Hormone Therapy with Estrogen”)

It is also important to remember that because everyone is different, medications and dosages may be different from person to person. Many people are eager for changes to take place rapidly and believe taking more medication will make changes occur faster; this is not necessarily true. Someone starting testosterone is initiating a puberty, and puberty normally takes several years for the full effects to be seen. Taking higher doses of hormones will not necessarily make things move more quickly — it may, however, endanger a user's health. (Seattle Children’s Gender Clinic, “A Guide to Gender Affirming Hormone Therapy with Testosterone”)

What is it?[4]

Testosterone is a sex steroid hormone made by all bodies but made most in bodies with testicles. Hormones tell cells what to do, which affects bodies and brains. (Cleveland Clinic, “Testosterone”; UCSF “Overview of masculinizing hormone therapy”; Seattle Children’s Gender Clinic, “A Guide to Gender Affirming Hormone Therapy with Testosterone”)

What does it do?

Testosterone may cause the following changes in your body within these general timeframe (however, ultimately it varies from person to person):

1) Physical Changes

Skin:

The first changes people using testosterone generally notice are to their skin and their smell. Skin typically becomes a bit thicker and oilier, and pores become larger and produce more oil. Some people develop acne, which can be bothersome or severe. Acne can be managed with good skin care as well as typical acne treatments. Sometimes people notice that pain and temperature perception change, or things "just feel different." In addition to these skin changes, people generally report changes in the odor of their sweat and urine, as well as increased production of sweat overall.

Chest:

Generally, chests do not change much through testosterone use, although some people notice some breast pain or a slight decrease in size. For this reason, many top surgeons recommend waiting for at least 6 months after beginning testosterone therapy before having chest reconstruction surgery.

Weight:

When people start using testosterone, they often notice a difference in fat distribution, and sometimes weight as well. Typically, body fat diminishes somewhat around the hips and thighs, and the fat under the skin throughout the body becomes a bit thinner, giving the arms and legs more muscle definition and a slightly rougher appearance. Testosterone may increase fat around the abdomen. Muscle mass and strength typically increase significantly. However, to maximize development and maintain health, people using testosterone should exercise most days (4-6 times a week) with a goal of at least 60 minutes per day, mixing resistance training with aerobic training. It can be helpful to focus some weight training on the upper body as this will typically enhance muscle development of arms, chest, and back, which can help ensure best results for people who decide to have top surgery.

In addition to changes in body fat, people using testosterone often notice that the fat in their faces decreases and shifts around, giving their eyes and faces in general a more angular, sharper appearance. However, bone structure does not change, unless someone begins using testosterone in their teens or early twenties, in which case they may see very subtle bone changes. The facial changes can take as long as 2 or more years to see the final result.

Hair:

Testosterone typically increases the thickness and rate of growth of body hair. Most people who go from being estrogen forward to testosterone forward find they develop patterns of body hair similar to that of other testosterone-forward people in their families. That said, everyone is different, and also it can take 5 years or more to see the final results. In terms of hair on the head, most people notice some degree of frontal scalp balding, mostly around the temples. Depending on age and family history, someone may develop thinning or even complete hair loss on the top and front of the head first.

Facial hair varies from person to person. Some people develop a thick beard quite rapidly, others may take several years to do so. This is a result of genetics and the age at which someone starts testosterone therapy. Cisgender men also have a varying degree of facial hair thickness, and varying age at which their facial hair is fully developed.

2) Emotional Changes

Puberty is frequently a roller coaster of emotions, and many people find the puberty they initiate with testosterone therapy is no exception. Some people find that they have access to a narrower range of emotions and feelings, have different interests, tastes, pastimes, and patterns of relationships with other people. While mental health counseling is not for everyone, most people would benefit from a course of supportive mental health counseling [6][7][8]while in transition to help with exploration of these new thoughts and feelings. Most people describe a significant improvement in overall well-being after gender affirming hormone therapy has begun, perhaps due to better alignment of the physical body with psychological gender identity.

3) Sexuality Changes:

Soon after beginning hormone treatment, most people notice a change in libido. Someone with a clitoris who is using testosterone will generally find the clitoris begins to grow, and becomes larger when they are aroused. Some people find that there are different sex acts or different parts of the body that bring sexual pleasure. Orgasms typically begin to feel different, with perhaps more peak intensity, and more focused on the genitals, as opposed to a whole-body experience. Many people find it helpful to experiment with getting to know their new sensations and desires, whether through masturbation, using sex toys (remember to clean and sterilize between uses), or involving a sexual partner or partners.

4) Reproduction & Fertility Changes

Periods:

When people who get periods first start using testosterone, they usually find that their periods become lighter, arrive later, and/or are shorter in duration than previously. It is also possible to have heavier or longer-lasting periods for a few cycles before they stop altogether. Usually, it takes 6-12 months for menstrual periods to stop completely.

Pregnancy:

Testosterone greatly reduces a person's ability to become pregnant. However, it is not a reliable form of birth control! If someone who is capable of getting pregnant is using testosterone and having the type of sex where sperm might get near their genitals, they must continue to use an alternative birth control method to prevent pregnancy. Testosterone is generally not considered safe to use during pregnancy.

It is possible for people who are able to get pregnant to become pregnant even while on testosterone. Someone who is using testosterone who thinks they may be pregnant should take a pregnancy test as soon as possible and discuss their plan with their medical provider.

People who are using testosterone who want to become pregnant should consult with their medical providers as soon as possible, and heed all advice from their providers when trying to conceive. Treatment providers will most likely advise discontinuation of testosterone during the process of conception and gestation, and may check your testosterone levels before clearing someone to begin efforts of conception.

WARNING: Testosterone therapy may alter and decrease ovulation and permanently decrease a user's ability to become pregnant. Someone who is planning to use testosterone should discuss options for fertility preservation with their treatment provider. Although expensive and not always successful, freezing embryos or eggs is sometimes an alternative option for trying to preserve fertility. It is quite possible that someone using testosterone will lose their ability to have a biological child completely. However, if someone is 2 or more years after the start of their periods, their future fertility will probably be more resilient. There are many examples of people using testosterone for 5-10 years and still being able to carry a pregnancy or access their fertility. This may not feel important right now, but it is a major decision. People thinking about using testosterone should spend time thinking about the possibility they may want to carry, or contribute genetic material, to children in the future and discuss it with people close to them.

Breakthrough bleeding:

After being on testosterone for some time, people sometimes experience a small amount of spotting or “breakthrough bleeding.” This sometimes occurs if someone misses a dose or changes dosage. Any bleeding or spotting should be brought to the attention of a treatment provider; in some cases, it must be followed up with an ultrasound (and sometimes a biopsy as well) to be sure that there are no problems with the uterus.

Physical changes have been compiled from UCSF “Overview of masculinizing hormone therapy”; Seattle Children’s Gender Clinic, “A Guide to Gender Affirming Hormone Therapy with Testosterone”, and Fenway Health, “Medical Care of Gender Diverse Children and Adolescents.”

What are the risks (besides possible loss of fertility)?

Cancer risks:

The risk of cervical cancer is primarily related to past and current sexual practices. The HPV vaccine can greatly reduce the risk of cervical cancer, depending on the age at which one gets the vaccine, and how many sexual partners one has had before receiving the vaccine. Cervical cancer screening is generally recommended every 3-5 years starting at age 21, although a doctor may recommend more or less frequent screening depending on the results of your prior screening and your sexual history.

The risk of cancer of the ovaries while on testosterone treatment is not thought to be increased. The studies we have show no increase but there are not enough studies to know for sure. Ovarian cancer is difficult to screen for, most cases occur between the ages of 45 and 65, and are often discovered at an advanced stage. A pelvic examination, where your doctor uses a gloved hand to examine the genitals, uterus, and ovaries, is recommended every 1-2 years to help detect this condition.

The risk of breast cancer while on testosterone treatment is not thought to be significantly increased. However, there has not been enough research on this topic to be certain of the actual risk. It is still important to receive periodic mammograms or other screening procedures as recommended by your doctor. After breast removal surgery, there is still a small amount of breast tissue left behind. It may be difficult to screen this small amount of tissue for breast cancer, but there have been almost no cases of breast cancer after chest reconstruction surgery.

Increased red blood cell count:

Testosterone can make blood become too thick, which can cause a stroke, heart attack, or other conditions. Testosterone can cause the liver to work too hard, causing damage. Treatment providers will perform periodic tests of blood count, cholesterol, kidney functions, liver functions, and a diabetes screening test to closely monitor testosterone therapy. Testosterone levels need to be routinely checked during the first year or two of transition, and then periodically after that.

Other health risks

Testosterone may change overall health risk profile. The risk of heart disease, diabetes, high blood pressure, and high cholesterol may go up, though these risks may be less than a cisgender man’s risks.[9][10][11]Since cismen on average live about 5 years less than ciswomen, theoretically someone could be shortening their lifespan by several years by taking testosterone.

Reversibility:

Some of the effects of hormone therapy are reversible if someone stops taking testosterone. The degree to which the effects can be reversed depends on how long the testosterone has been used. Clitoral growth, hair growth, voice changes, and hair loss are not generally reversible without other interventions.

If someone has had their ovaries removed, it is important to remain on at least a low dose of hormones until age 50 (and perhaps beyond), to prevent a weakening of the bones, otherwise known as osteoporosis. Calcium and vitamin D supplements to help maintain healthy bones are also recommended.

Risks complied from UCSF “Overview of masculinizing hormone therapy”; Seattle Children’s Gender Clinic, “A Guide to Gender Affirming Hormone Therapy with Testosterone”, and Fenway Health, “Medical Care of Gender Diverse Children and Adolescents.”

What forms do they come in?

Testosterone comes in pills, injections, and gels. Most adolescents take gel or injections because the pills can’t be cut to decrease the dose. (Fenway Health, “Hormone Options: Testosterone Therapy”)

How to take it?

All of the information below is compiled from Seattle Children’s Gender Clinic “Gender-Affirming Hormone Protocols” and Fenway Health’s “Medical Care of Gender Diverse Children and Adolescents.”

NOTE: The information has been collected to create a comprehensive guide for individuals and health care professionals less familiar with these treatment regimens, but is NOT intended to be a substitute for medical advice from a doctor or other health care professional familiar with your particular case and medical history. Use these medications as directed by a treatment provider.

It is often recommended to start at a lower dose than listed here, and increase over time.

Testosterone forms:

• Gel — comes in 1% or 1.62% pumps or packets. It must be applied everyday

  • Starting doses

    • Early adolescence (9–12): ½ pump or packet

    • Middle adolescence (13–15): ½ to 1 pump or packet

    • Late adolescence (15+): 1 pump or packet

  • Dose increases

    • Early adolescence (9–12): increase by ½ pump or packet every 6 months

    • Middle adolescence (13–15): increase by ½ pump or packet every 3–6 months

    • Late adolescence (15+): increase by 1 pump or packet every 3–6 months

  • Most adults take between 4–5 pumps or packets a day.

  • Apply to upper arms or legs. Let dry (it will remain a little tacky). Wash hands. Cover the skin where you applied the gel. Avoid contact with other humans or animals on the treated area until you have showered. Wash laundry separately. You are more likely to have darker and thicker body hair at sight of application.

• Injections

  • Testosterone cypionate 100 mg/mL or 200 mg/mL or testosterone enanthate 200mg/mL injected subcutaneously once per week.

    • Early adolescence (9–12): 10 mg (0.1mL of 100 mg/mL or 0.05mL of 200 mg/mL)

    • Middle adolescence (13–15): 10 mg (0.1mL of 100 mg/mL or 0.05mL of 200 mg/mL)

    • Late adolescence (15+): 10–20 mg (0.2mL of 100 mg/mL or 0.1mL of 200 mg/mL)

    • Dose increases

      • Early adolescence (9–12): increase by 10 mg every 6 months

      • Middle adolescence (13–15): increase by 10 mg every 3–6 months

      • Late adolescence (15+): increase by 10–20 mg every 3–6 months

    • Most adults take between 60–100 mg once per week.

WARNING: Taking more testosterone will not make changes progress more quickly and can be unsafe. Excess testosterone can be converted to estrogen, which can then increase risks of endometrial hyperplasia or cancer, cause anxiety or agitation, lead to liver damage, and/or cause cholesterol or blood count to get too high. It is important to be patient and remember that this puberty can take years to move through all of its changes.

References

1. E. Coleman, A. E. Radix, W. P. Bouman, G. R. Brown, A. L. C. de Vries, M. B. Deutsch, R. Ettner, L. Fraser, M. Goodman, J. Green, A. B. Hancock, T. W. Johnson, D. H. Karasic, G. A. Knudson, S. F. Leibowitz, H. F. L. Meyer-Bahlburg, S. J. Monstrey, J. Motmans, L. Nahata, T. O. Nieder, S. L. Reisner, C. Richards, L. S. Schechter, V. Tangpricha, A. C. Tishelman, M. A. A. Van Trotsenburg, S. Winter, K. Ducheny, N. J. Adams, T. M. Adrián, L. R. Allen, D. Azul, H. Bagga, K. Başar, D. S. Bathory, J. J. Belinky, D. R. Berg, J. U. Berli, R. O. Bluebond-Langner, M.-B. Bouman, M. L. Bowers, P. J. Brassard, J. Byrne, L. Capitán, C. J. Cargill, J. M. Carswell, S. C. Chang, G. Chelvakumar, T. Corneil, K. B. Dalke, G. De Cuypere, E. de Vries, M. Den Heijer, A. H. Devor, C. Dhejne, A. D’Marco, E. K. Edmiston, L. Edwards-Leeper, R. Ehrbar, D. Ehrensaft, J. Eisfeld, E. Elaut, L. Erickson-Schroth, J. L. Feldman, A. D. Fisher, M. M. Garcia, L. Gijs, S. E. Green, B. P. Hall, T. L. D. Hardy, M. S. Irwig, L. A. Jacobs, A. C. Janssen, K. Johnson, D. T. Klink, B. P. C. Kreukels, L. E. Kuper, E. J. Kvach, M. A. Malouf, R. Massey, T. Mazur, C. McLachlan, S. D. Morrison, S. W. Mosser, P. M. Neira, U. Nygren, J. M. Oates, J. Obedin-Maliver, G. Pagkalos, J. Patton, N. Phanuphak, K. Rachlin, T. Reed, G. N. Rider, J. Ristori, S. Robbins-Cherry, S. A. Roberts, K. A. Rodriguez-Wallberg, S. M. Rosenthal, K. Sabir, J. D. Safer, A. I. Scheim, L. J. Seal, T. J. Sehoole, K. Spencer, C. St. Amand, T. D. Steensma, J. F. Strang, G. B. Taylor, K. Tilleman, G. G. T’Sjoen, L. N. Vala, N. M. Van Mello, J. F. Veale, J. A. Vencill, B. Vincent, L. M. Wesp, M. A. West & J. Arcelus (2022) Standards of Care for the Health of Transgender and Gender Diverse People, Version 8, International Journal of Transgender Health, 23:sup1, S1-S259, DOI: 10.1080/26895269.2022.2100644. https://doi.org/10.1080/26895269.2022.2100644

2. Wylie C Hembree, Peggy T Cohen-Kettenis, Louis Gooren, Sabine E Hannema, Walter J Meyer, M Hassan Murad, Stephen M Rosenthal, Joshua D Safer, Vin Tangpricha, Guy G T’Sjoen, Endocrine Treatment of Gender-Dysphoric/Gender-Incongruent Persons: An Endocrine Society Clinical Practice Guideline, The Journal of Clinical Endocrinology & Metabolism, Volume 102, Issue 11, 1 November 2017, Pages 3869–3903, https://doi.org/10.1210/jc.2017-01658

3. Thompson, J, Cavanaugh, T, Hopwood, RA, & Vetters, R. Protocol for the Gender Affirming Care of Transgender, Non-binary, and Gender Diverse Children and Adolescents. April 2019. Fenway Health, Boston. https://fenwayhealth.org/wp-content/uploads/Medical-Care-of-Gender-Diverse-Children-Fenway-Health-Spring-2019-1.pdf

4. Seattle Children's. (2023, June). Seattle Children’s Gender Clinic Gender-Affirming Hormone Protocols. https://www.seattlechildrens.org/globalassets/documents/clinics/gender/scgc-gah-protocols.pdf