The Study
Erythrocytosis Is Rare With Exogenous Testosterone in Gender-Affirming Hormone Therapy.
This study looked at a bunch of people taking testosterone and saw that those with higher testosterone levels tended to have higher blood thickness, but it didn’t prove that testosterone made the blood thicker—it just noticed a pattern. So we can’t say testosterone causes it, only that they’re linked.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
When people take testosterone for gender-affirming care, their bodies sometimes make more red blood cells, which can thicken the blood. This study looked at thousands of people to see how often this happens and what makes it more likely.
Where does this study sit?
Systematic Reviews & Meta-analyses
Max 100Randomized Trials
Max 90Cohort Studies
Max 72Case-Control
Max 58Cross-Sectional
Max 44Case Reports & Series
Max 30Expert Opinion
Max 535 / 100
Quality score
Detailed descriptions of individual patients or small groups. Valuable for identifying new conditions or side effects, but cannot establish generalizable conclusions.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Even the highest red blood cell levels seen (45.68%) are still within the normal range for healthy men, and very few people reached dangerous levels.
- 28.4% had very high red blood cell levels (hematocrit ≥50%), 2.7% had even higher (≥52%), and only 0.9% had the highest (≥54%).
- 3The more testosterone in the blood, the higher the red blood cell count — up to 45.68% at the highest levels.
- 4Shots of testosterone led to higher levels than gels or patches.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
The Journal of clinical endocrinology and metabolism
Year
2023
Authors
N. Krishnamurthy, Daniel J. Slack, Moira Kyweluk, Olivia Cullen, Jerrica Kirkley, J. Safer
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.