Testosterone replacement therapy (TRT) can be an effective treatment for low testosterone in both males and females, addressing symptoms like fatigue, low libido, and loss of muscle mass. However, it’s essential for patients to be aware of potential side effects, including an increase in hemoglobin and hematocrit (red blood cell count), which can lead to a condition called polycythemia or erythrocytosis.
Here’s why hemoglobin (Hgb) and hematocrit (Hct) need to be monitored and sometimes managed with blood donation (therapeutic phlebotomy):
Why TRT Raises Hgb/Hct
- Testosterone stimulates erythropoiesis → it signals the kidneys to produce more erythropoietin (EPO), which then stimulates the bone marrow to produce more red blood cells, ultimately boosting red blood cell production.
- More red blood cells = higher hemoglobin (the oxygen-carrying protein) and hematocrit (the percentage of blood volume made of red cells).
- This effect is more pronounced in injectable TRT compared to gels or pellets.
Risks of Elevated Hgb/Hct
When hematocrit climbs above the safe range (generally >52–54%), the blood becomes more viscous (“thicker”):
- Blood clot risk increases (deep vein thrombosis, pulmonary embolism, stroke).
- Cardiovascular strain → thicker blood makes the heart work harder, raising blood pressure and cardiovascular risk.
- Poor oxygen delivery → paradoxically, very high hematocrit can reduce oxygen delivery efficiency, causing fatigue, headaches, dizziness, or vision issues.
Why Monitoring is Critical
- Most doctors will check CBC (complete blood count) every 3–6 months to ensure the body is in a safe healthy range.
- Hematocrit above certain levels often triggers intervention.
- Patient demographics, including elevation where they reside, are taken into consideration
Role of Blood Donation / Phlebotomy
If Hgb/Hct is elevated:
- Therapeutic phlebotomy (prescribed blood removal, similar to a donation) lowers red blood cell mass quickly.
- Regular blood donation (if eligible) is another way to keep levels in check.
- Dosage adjustment or switching the TRT delivery method may also reduce the rise.
Bottom line:
On TRT, managing hemoglobin and hematocrit is critical to avoid complications from “thick blood.” Monitoring ensures that therapy remains safe, and donations (or dose adjustments) are effective tools to keep levels in the healthy range.
Frequently asked questions:
What is the link between testosterone therapy and increased hemoglobin/hematocrit?
- Testosterone stimulates the production of red blood cells, which can cause both hemoglobin (the protein that carries oxygen in red blood cells) and hematocrit (the percentage of blood volume made up of red blood cells) to increase.
- While a normal increase in red blood cells is a desired effect in patients with anemia, an excessive increase (polycythemia) can lead to the blood becoming thicker or more viscous.
What are the potential risks of elevated hemoglobin/hematocrit?
- High blood viscosity can increase the risk of blood clots, which could lead to serious events like deep vein thrombosis, pulmonary embolism, heart attack, or stroke.
What are the signs and symptoms of high hemoglobin/hematocrit?
- Symptoms might include dizziness, headaches, neck pain, chest pain, shortness of breath, fatigue, weakness, swollen hands and feet, or facial redness.
- It’s important to note that some individuals may experience no symptoms, highlighting the importance of regular monitoring.
What should I consider if I want to start taking testosterone?
- Always discuss the potential risks and benefits of testosterone therapy with your provider before starting treatment.
- Follow your provider’s instructions for monitoring and managing hemoglobin/hematocrit levels and report any new or worsening symptoms promptly.
- Never adjust your testosterone dosage or stop therapy without consulting your provider.
By being informed about the potential for increased hemoglobin and hematocrit with testosterone therapy, patients can work with their healthcare providers to manage this risk effectively and maximize the benefits of treatment.
Our medical team at All U Health has years of experience treating hormones and the goal is to educate and provide the best possible therapy for each individual guest.
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References:
https://www.ahajournals.org/doi/10.1161/circ.144.suppl_1.9682
https://www.medscape.com/viewarticle/diet-and-exercise-pill-are-real-how-mimetics-work-2024a10004rt