Related Experiment Video
Updated: Feb 17, 2026

Bone Marrow Transplantation Procedures in Mice to Study Clonal Hematopoiesis
Published on: May 26, 2021
Testosterone replacement therapy (TRT) and its effect on bone marrow. How serious is it and is there a true
Introduction:
TRT in men with testosterone deficiency syndrome (TDS) had multiple positive effects and restore a quality of life of affected men. Polyglobulia is the most common dose-limiting adverse effect of TRT, but the mechanisms of TRT-mediated erythropoesis remain unclear. In this study, we evaluated long term haematological side effects of TRT: polyglobulia, elevated hemoglobin (Hb) and haematocrit (Ht).
Methods:
In a cross-sectional descriptive study, the authors treated 69 men with TDS and the average age 59 years and the follow-up period 81.32 months. The men were treated with three-month i.m. injections of 1000 mg testosterone undecanoate. The elevated values were: Hb above 176 g/l, Ht above 0.52 and erythrocytes (Ery) above 6.0 mil/mcl.
Results:
21 out of 69 patients (30.43 %) had an increased Hb, Ht or Ery during treatment. The interesting fact was that only five men (7.24 %) had increased the number of Ery (true polyglobulia). No men with elevated level of Hb, Ht or Ery had other side effects (like thrombosis).
Conclusion:
It is still not clear, why in some men on TRT the feedback does not work and bone marrow production of red blood cells continues even if the upper limit is reached. Authors expect that only 7% of men had true polyglobulia, other men had elevated Hb or Ht. Based on our own experience we recommend a regular check of men on TRT on order to avoid possible serious side-effects (Tab. 1, Fig. 2, Ref. 25).
Related Concept Videos
Bone Marrow Sampling and Transplants
The transplant begins with high doses of chemotherapy and radiation treatment, which aim to destroy...
Factors Affecting Erythropoiesis
Several factors influence the erythrocyte production rate, with tissue oxygen level being among the most critical. Intense exercise or high altitudes can cause tissue hypoxia, which triggers the kidneys to release more erythropoietin (EPO) into the bloodstream.
EPO then...
Stem Cell Therapy for Tissue Regeneration
Types of Stem Cells used in Stem Cell Therapy
The two main cell...
Disorders of Erythrocytes
Erythrocyte disorders can be broadly categorized into two main types: anemic and polycythemic conditions.
A low oxygen-carrying capacity of the blood due to the loss, lower production, or destruction of erythrocytes is termed anemia. Hemorrhagic anemia, for example, occurs when bleeding from an external wound or internal ulcer reduces erythrocyte counts.
On the other...
Role of Hematopoietic Growth Factors
Thrombopoietin (TPO), mainly released by the liver,...
Bone Disorders
Bone deposition is also affected by the levels of sex hormones like estrogen and testosterone that promote osteoblast activity and bone matrix synthesis. When the level of these hormones decreases due to aging, it causes a reduction in bone deposition. As a result, bone resorption by osteoclasts...

