How to Manage Increased Blood Thickness (Hematocrit) Caused by Testosterone Replacement Therapy

Depositphotos 3306438 m 2015

Testosterone Replacement Therapy and Polycythemia
By Nelson Vergel, B.S.Ch.E., M.B.A.

Polycythemia is an excessive production of red blood cells. With polycythemia the blood becomes very viscous or “sticky,” making it harder for the heart to pump. High blood pressure, strokes and heart attacks can occur.

The association between testosterone replacement therapy and polycythemia has been reported for the past few years as this therapy has become more mainstream. In addition to increasing muscle and sex drive, testosterone can increase the body’s production of red blood cells. This hematopoietic (blood-building) effect could be a good thing for those with mild anemia.

Although all testosterone replacement products can increase the amount of red blood cells, the study showed a higher incidence of polycythemia in those using intramuscular testosterone than topical administration (testosterone patch was the main option used — no gels). Smoking has also been associated with polycythemia and may contribute to the effects of other risk factors.

Below is an excerpt from my book, Testosterone: A Man’s Guide, further detailing the prevention and management of polycythemia.

Preventing and Managing Polycythemia

It’s important to check patients’ hemoglobin and hematocrit blood levels while on testosterone replacement therapy. As we all know, hemoglobin is the substance that makes blood red and helps transport oxygen in the blood. Hematocrit reflects the proportion of red cells to total blood volume. A hematocrit of over 52 percent should be evaluated. Decreasing testosterone dose or stopping it are options that may not be the best for assuring patients’ best quality of life, however. Switching from injectable to transdermal testosterone may decrease hematocrit, but in many cases not to the degree needed.

The following table shows the different guideline groups that recommend monitoring for testosterone replacement therapy. They all agree about measuring hematocrit at month 3, and then annually, with some also recommending measurements at month 6 after starting testosterone (it is good to remember that there is a ban on gay blood donors in the United States).

Name: table5guidelines.jpg Views: 59962 Size: 24.4 KB

Many patients on testosterone replacement who experience polycythemia do not want to stop the therapy due to fears of re-experiencing the depression, fatigue and low sex-drive they had before starting treatment. For those patients, therapeutic phlebotomy may be the answer. Therapeutic phlebotomy is very similar to what happens when donating blood, but this procedure is prescribed by physicians as a way to bring down blood hematocrit and viscosity.

A phlebotomy of one pint of blood will generally lower hematocrit by about 3 percent. I have seen phlebotomy given weekly for several weeks bring hematocrit from 56 percent to a healthy 46 percent. I know physicians who prescribe phlebotomy once every 8-12 weeks because of an unusual response to testosterone replacement therapy. This simple procedure is done in a hospital blood draw or a blood bank facility and can reduce hematocrit, hemoglobin, and blood iron easily and in less than one hour.

Unfortunately, therapeutic phlebotomy can be a difficult option to get reimbursed or covered by insurance companies. The reimbursement codes for therapeutic phlebotomy are CPT 39107, icd9 code 289.0.

Unless a local blood bank is willing to help, some physicians may need to write a letter of medical necessity for phlebotomy if requested by insurance companies. If the patient is healthy and without HIV, hepatitis B, C, or other infections, they could donate blood at a blood bank.

One unit of whole blood is around 350 to 450 cc; approximately 4 units of blood need to be withdrawn to decrease this man’s hemoglobin from 20 mg/mL to 14 mg/mL. However, taking this much blood out in one phlebotomy session may deplete ferritin and iron levels which can cause extreme fatigue. So, be conservative give 1-2 units max even if you have to go more frequently. Donations more frequently than every 3 months run the risk to lower your ferritin and iron too much (which can cause fatigue), so make sure that you measure these two variables to determine if you should take an iron supplement.

You can order a CBC test (includes hematocrit) and ferritin (after you donate blood) here: Blood tests

The frequency of the phlebotomy depends on individual factors, but most men can do one every two to three months to manage their hemoglobin this way. Sometimes red blood cell production normalizes without any specific reason. It is impossible to predict exactly who is more prone to developing polycythemia, but men who use higher doses, men with sleep apnea, and older men may have a higher incidence. It is important not to draw too much blood at once due to dramatic decreases in iron levels and ferritin that could cause fatigue.

Some doctors recommend the use of a baby aspirin (81 mg) a day and 2,000 to 4,000 mg a day of omega-3 fatty acids (fish oil capsules) to help lower blood viscosity and prevent heart attacks. These can be an important part of most people’s health regimen but they are not alternatives for therapeutic phlebotomy if the patient has polycythemia and does not want to stop testosterone therapy. It is concerning that many people assume that they are completely free of stroke/heart attack risks by taking aspirin and omega-3 supplements when they have a high hematocrit.

Although some people may have more headaches induced by high blood pressure or get extremely red when they exercise, most do not feel any different when they have polycythemia. This does not make it any less dangerous.


Donating more than 1 unit every 2-3 months may lower your iron and ferritin levels and cause fatigue. That is why it is good to start donating when you are in the 51-52 hematocrit range. Also, the Red Cross and other organizations will reject donors with high hematocrit over 52. Those who get rejected can ask for a written order from their doctors and may have to pay to get phlebotomies.

Name: iron loss donation.jpg Views: 30714 Size: 168.2 KB

Balancing low ferritin levels and frequent donation.

Warning about frequent blood donations used to decrease hematocrit.


Please enter your comment!
Please enter your name here