Testosterone HRT Labs at FOLX

Everything you need to know about testosterone HRT/GAHT labs with FOLX including frequency, what we are looking for, and how we center our members' experiences.

October 3, 2022
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What do hormones do?

Hormones are chemical messengers in the body. Testosterone and estrogen are heavily involved in how our internal sense of gender develops and how our external presentation of gender manifests. Using testosterone hormone replacement therapy (HRT) to affirm your gender identity involves shifting from an estrogen-based system to a testosterone-based system. Testosterone—whether produced by the testes or supplied externally via a gel or injection—travels through the body to organs that have testosterone receptors.

Hormones change signals in the cell membrane to produce different proteins and different functions. For example, more testosterone means the skin will produce more oil, and hair will grow in thicker or darker. Muscle and fat tissue will redistribute in a more masculine pattern—more lean muscle mass and more muscle on the upper body. The muscles that control our voice lower it. Menstruation changes or stops since testosterone keeps estrogen from stimulating the uterine lining. These are a few examples of how testosterone HRT can change your body through gender-affirming hormone therapy (GAHT). 

Why do we need labs?

Gender-affirming hormones are used to meet our members' gender goals, which are different and unique to each person. We use labs as tools to assess the safety and effectiveness of the medication. Many people take testosterone HRT for the internal and external changes they will experience; labs are just one piece of data that can help you and your clinician determine the next steps. When our clinicians order labs for those on testosterone, we are testing for a couple of things.

We test your testosterone levels

A testosterone lab checks the amount of testosterone in the bloodstream at a single point in time.  The result is affected by many things including when you last took your dose, how much you take, how often you take or miss doses, and your metabolism. Labs aren’t a perfect source of truth but are impacted by multiple variables, and hormones are challenging to measure accurately for many reasons. It’s more important to focus on what testosterone is doing for you, and how it might or might not be meeting your specific goals. 

Let’s talk about how we use testosterone levels as a tool to help you get the results you want and need. Higher levels of testosterone can create changes more quickly, whereas lower levels of testosterone might create slower and more subtle changes, resulting in a more androgynous and/or less masculinizing outcome. There is a wide range for both testosterone doses and the lab levels we expect to see.

When testosterone levels are too high, we start to see negative effects and increased risk. Extremely high levels of testosterone do not necessarily mean faster, more, or better changes because once the testosterone receptors are full, they can’t continue to create changes beyond their capacity. Change might be affected by age, previous exposure to testosterone, and just plain family and genetic tendencies. If you aren’t seeing the changes you desire on GAHT, talk with your clinician. Part of that conversation might include what gender-affirming surgical options might off to meet your specific goals.

Also, it’s possible that high levels of testosterone actually get converted to estrogen. This is usually not the desired goal for those taking testosterone. We don’t know at exactly what level testosterone converts to estrogen, but this is why it’s important to keep an eye on your labs.

What testosterone range is normal?

We typically are looking for levels in a range from 250 to 1000 ng/dl (nanograms per deciliter). We use these as estimates to give us an idea of where your hormone levels are at a particular time. When levels are on the lower end, they can be increased and still stay within a safe and acceptable range. If levels are very high, this can increase risk for side effects such as very extreme moods, irritability, and fatigue.

We also check hemoglobin to make sure the blood isn’t too “thick”

Most people on testosterone will have an increase in their red blood cell count (RBC). The lab we use to estimate the changes in RBC is hemoglobin—the protein in red blood cells responsible for carrying oxygen from the lungs to the rest of the body. In most cases, these levels increase after starting testosterone. We monitor these levels to make sure the blood isn’t getting too “thick,” which would decrease blood flow and increase the risk of blood clots. Blood clots, in turn, can lead to risk of stroke or heart attack, so it’s crucial that we keep an eye on this.  However, in most circumstances, the typical increase in RBC does not put members at risk for the blood becoming “thicker.”

When people have hemoglobin over 20 g/dl (grams per deciliter) or more, we might recommend reducing the dose of testosterone, changing to testosterone gel, or donating blood. These changes typically bring hemoglobin down to safer ranges.  

What about all the other labs that some providers run?

At FOLX, we run standard labs associated with GAHT/HRT to ensure that these medications are safe, effective, and meeting your goals. We only run labs that are necessary for the care we are providing. These labs include hemoglobin (Hgb) and testosterone, depending on your symptoms and care plan.

Some people may have other chronic medical conditions that may benefit from closer lab evaluation, and these are reviewed during our Informed Consent process so that members can decide how to proceed. If you have certain medical conditions, we recommend you discuss them with your FOLX clinician, who can also be your primary care provider (PCP). In addition to GAHT, your care team can help you assess or manage other conditions.

FOLX pairs lab results with our members' lived experiences to make medical decisions

At FOLX, we want to help you meet your gender journey goals. We offer excellent care and provide evidence-based medical updates and information. The most important part of this process includes listening to what your specific gender goals are so that we can adjust your plan accordingly. While labs are important tools, we do not base medical decisions solely on lab numbers. We take a holistic perspective to assess the safest and most effective plan for you.

It's important for us to hear from our members about how they are feeling. We will communicate if there are any concerns about your lab results from a medical perspective, but we may not adjust dosages solely based on these results. We want to hear from our members themselves about what feels right in their bodies and how they want to move forward before finalizing any changes.

Lab results can vary

The time you get your labs done in relation to when you took your last dose of estrogen HRT greatly impacts your lab results. Levels also depend on how often you miss doses, how much medication you give yourself, and the way your body metabolizes medication. 

It can be harder to measure an accurate level of testosterone in the bloodstream for people who take weekly or biweekly injections because the level of testosterone cycles from very high immediately after injection to very low right before the next injection.

Therefore, it’s recommended those on injectable testosterone try to schedule labs around halfway between injections, or at the end of the injection cycle to get the most accurate results. For instance, if you inject on a Friday, it’s recommended you schedule lab work on a Monday or Tuesday.

For those on testosterone gel, there can be some fluctuation in levels, but the fluctuations will be less drastic than those on injectable T. We recommend getting testosterone levels 6-12 hours after transdermal dosing. To learn more about testosterone routes offered by FOLX, read up here.

Labs need to happen more frequently when starting or restarting testosterone

Typically, we check labs about every six months until we find the right regimen for you. We can check labs once per year after your doses are stable. Some folks may need labs more frequently depending on the situation.

We follow people starting hormones more closely during the first year of treatment. This looks like checking in with your clinician every three months during the first year to assess if your goals and needs are being met. 

We don’t necessarily need to get your hormone levels checked every three months, but it can often be helpful to get labs and levels around six months after starting T. For people without chronic medical conditions and minimal side effects, or those who are happy with their medication and meeting their gender goals we usually move to once-a-year blood work after your first year on testosterone.

FOLX wants to make getting labs done easy

FOLX orders lab draws at a member's nearest Quest Diagnostics Patient Service Center. Lab draws require going in person and having a vial of blood drawn through a needle. If you choose to go to Quest, it's important to know that they are required to use members' legal names on the lab requisition form. We know that this may lead to deadnaming or lab technicians using incorrect pronouns. If you experience anything like this at a Quest location, please let us know so that we can work on additional training and follow-up.

Read our Library article for more information on how to get your labs drawn at Quest or non-Quest locations.

Finally, for those switching over from a previous provider to FOLX for GAHT/HRT care, we can accept labs drawn within the last year, as long as they were done while on the same route and dosage requested from FOLX.

For those ready to get started with FOLX for estrogen, the process begins here. For existing FOLX members with additional questions about labs, don't hesitate to schedule time with a clinician. And for those who've just got some more questions, feel free to reach out to our Member Navigators at the FOLX Help Center.


FOLX Health is the first digital healthcare company designed by and for the LGBTQIA+ community. Our services include virtual primary care, gender-affirming hormone therapy including estrogen and testosterone (HRT), mental health care, sexual and reproductive health care, preventive care, and fertility consultations. FOLX memberships give you access to LGBTQIA+ expert clinicians, peer support, thousands of LGBTQIA+ resources, and more. Whether you’re lesbian, gay, bisexual, transgender, queer, gender non-conforming, or nonbinary, you can find LGBTQIA+-specialized health care that helps you meet your wellness goals. FOLX Health is health care that's queer all year. Get all the benefits of becoming a FOLX member and sign up today!