T Nation

Hematocrit: How High is Life Threatening?


That is NOT happening with me. My blood pressure is STILL LOW with high hematocrit. High T, FSH, SHBG, Low E2 No Libido. My Lab Results (pellets)

And how do you feel with the high hematocrit? I couldn’t tell one way or another except I looked reddish especially when I pressed on my skin. Now it’s almost gone. I’m sure it was the high total and free T, and my huge vitamin D3 intake. Will do blood work in 7 weeks as I just switched to 40mg twice weekly.
By the way traveling man, do you travel east in search of that which is lost? :sunglasses:

Hi, I don’t feel any different between hematocrit of 41 or 56. NOTHING.

High T did NOT affect my hematocrit in my case (proven by labs).

I have been off the high doses of Vit D for three months+ and hematocrit went higher, which in my case, tells me the two aren’t related.

I have said all along that I wanted to do a morning blood test for CBC (fasting) and an afternoon one (no fasting) to see if there is a difference. That is scheduled for tomorrow.

I believe I have found the lost world … and if I could swing it with work, I would never return to the USA. But alas, I don’t have that ability.

Ok I thought you were a Freemason (hence the weird question) Lol. So if high T didn’t bring up your hematocrit, what did? And is it still high? What protocol are you on?

My study of Hematocrit early morning and afternoon failed to prove my theory.

I would say keep an eye on things and go from there. Ive taken 10k iu a day for years to keep my D level in the low 60s.

To note I also have a genetic mutation for decreased vitamin D absorption.

Yeah I’d definitely say that you qualify as the “exception” lol.

TBH Im not sure how uncommon it is. BUT if someone is taking 10k iu a day they should obviously be monitoring.


More reading …

There is overwhelming evidence that values up to 18 g/dL (for hemoglobin concentration) or 53% (for hematocrit) should not be considered elevated in white or Asian men who live at altitudes of 1000 m (approximately 3000 ft) above sea level or less.

However, it is prudent to determine that this is a stable value rather than an increase from a prior value of 16 or 17 g/dL. Source

(mine is not stable - it is an increase)

In my case Hemoglobin and Hematocrit are the only concerning numbers. Platelet and Leukocyte counts are mid-normal which rules out a number of things (from what I am reading) including Polycythemia Vera.

When you suspect an obscure cause of elevated hemoglobin concentration and hematocrit, measure arterial blood gases.

I’m still looking for these tests …

I also ruled out anemia, because of my Hemoglobin levels.

I feel good … USA doctor isn’t worried about high HCT, but Asian doctor almost stroked. That has caused me to start looking for more answers. I watched both videos posted on higher HCT being ok … but I’m trying to do due diligence.

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@hrdlvn - IN MY SITUATION, that didn’t work. I was hoping that my high HCT was due to something simple like overnight dehydration but I proved that theory wrong.

My theory now is that hydration has to be continuous for a few weeks at least prior to the test. The night I got the 58 reading I actually drank like 1 gallon of water in the previous 2-3 hours. So I think hydration must be constant for a while.

I believe you. My doc always says be well hydrated before doing the blood draw an it has never really helped me with high HCT.
I really think the only way to reduce HCT once it is thru the roof is move to the ocean(sealevel) I live at 8000ft on the Western slope of the Rockies or cut your T dose…by a lot.

So couldn’t that be the reason your hematocrit is high? Cause you live at 8000 ft above sea level?
From my recent research it seems that unlike polycythaemia, when testosterone increases red blood cells and haemoglobin (hence increasing hematocrit) it compensates by vasodilation of arteries and nitric oxide release. So if blood is thicker it’s moving through wider arteries and veins which also explains the nice huge pumps at the gym. Also ferritin iron stores are lowered as it’s using that stored iron to increase red blood cells. So unlike anemia, ferritin is lowered but iron in the body is not. I’ve lowered my Testosterone from 100 mg once a week to 80 mg split every 3.5 days and the only side effect I had before (red face and skin) is now gone after one week. I was also over responding to 100 mg a week. 1233 ng/dl on day 2 and 704 on day 8

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Absolutely, but try and convince the man that writes the T script that.
Even the local blood banks say no thank you we don’t want your free donation if your finger stick is 19 or higher

New articles (to me) that I am reading …

Hematocrit elevation following testosterone therapy – does it increase risk of blood clots?
Includes a chart showing the expected amount of hematocrit increase based on the type of testerosterone you are taking. Nebido

Same source as above
" A second reason that elevations in hematocrit with testosterone treatment may not be inherently dangerous is that low testosterone levels are associated with higher levels of prothrombotic factors in men, regardless of age, obesity, body fat distribution, and related metabolic parameters.[78]"

Testosterone-induced increase in hemoglobin and hematocrit is associated with stimulation of EPO and reduced ferritin and hepcidin concentrations. We propose that testosterone stimulates erythropoiesis by stimulating EPO and recalibrating the set point of EPO in relation to hemoglobin and by increasing iron utilization for erythropoiesis. Source

The normal range for EPO levels can vary from 3.7 to 36 international units per liter (IU/L). Higher-than-normal levels may mean you have anemia. In severe cases of anemia, EPO levels in the blood may be a thousand times higher than normal. Unusually low levels may be because of polycythemia vera. This is a bone marrow disorder that causes your body to make too many red blood cells. Low EPO levels may also mean you have kidney disease. Source

I have been reading about EPO and its tie to HCT/HGB. What surprises me is that low HGB is an automatic indicator of anemia; so I guess low EPO would only confirm the diagnosis. I have also read a lot about higher HGB leading to potential lung/COPD problems. “Consequently, someone who has lung or kidney disease, who smokes, or is dehydrated, may be at risk of increased hemoglobin levels.”

Another study found that EPO was not effected by increases in HCT/HGB caused by Testosterone supplementation. " Hemoglobin and hematocrit increased significantly in a linear, dose-dependent fashion in both young and older men in response to graded doses of testosterone. The increases in hemoglobin and hematocrit were significantly greater in older than young men. There was no significant difference in percent change from baseline in erythropoietin. Changes in erythropoietin levels were not significantly correlated with changes in total or free testosterone levels. Source

Many of the articles I read mention that the people visiting doctors with high HCT/HGB were experiencing SYMPTOMS such as “red face, some shortness of breath, dizziness, etc” which is an interesting point to note in cases like mine where I do not notice any symptoms.

Hematocrit may stabilize in men after 18 months of testosterone replacement. It is impossible to predict if your hematocrit will slowly decrease now that you remain on TRT. Source Nelson Vergel And The best way to bring hemoglobin and hematocrit down while staying on testosterone replacement is donating blood (unless HCT is too high, then therapeutic phlebotomy at a doctor’s office). 4-5 units every 2-3 months are usually OK for hemoglobin to drop below 17.

The statement that HCT might “stabilize” after 18 months of continued T-supplementation is one that I can only find ONE person making that statement with no supporting evidence.

I would have thought that getting rid of so much blood would have a large effect or Iron/Ferritin. Ah, here it is: “An important warning about frequent blood donations or therapeutic phlebotomies: Iron and ferritin levels can drop and make you feel tired. The Red Cross recommends no more than 1 phlebotomy every 2 months for that reason.”

This is another statement I find interesting. Men who supplement with Testosterone are 315% more likely to have increased HCT but there isn’t enough concrete data to show that it has the same affects as men who are not on T-supplementation with high HCT.

Men undergoing TRT have a 315% greater risk for developing erythrocytosis (defined as Hct > 0.52) when compared with control. Mechanisms involving iron bioavailability, erythropoietin production, and bone marrow stimulation have been postulated to explain the erythrogenic effect of TRT. The association between TRT‐induced erythrocytosis and subsequent risk for VTE remains inconclusive. Source

There are doctors (such as Neal Rouzier) who believe that the increases in HCT/HGB from T-patients is the new “normal”. He does not believe in “blood lets” in T-patients. A video interview with him is on this page.

Two tests are suggested … one is EPO (Erythropoietin) which is only $59. The second test is for “blood gases” and I am not having any luck finding online labs that do this one.

Yes, I know. I can’t write short posts. At least this isn’t twitter. I hope this helps someone as it gives me a better understanding of where I am.


I enjoyed reading your post. You understand paragraphs and avoid walls of text those are the posts I skip over.


I think we all freaked out for no reason. My hematocrit was 58 on the second last test. Then 53 a few days later. Either way I had zero symptoms or side effects other then a more reddish complexion. From my further research it all makes more sense now. It’s simple. Testosterone stimulates red cell production. Hemoglobin is then formed quickly from ferritin stores, which drop quickly BUT iron levels in the body are not affected and stay stable. Testosterone also compensates for this blood thickening by increasing nitric oxide whice is a vasodilator and enlarges your veins and arteries. Hence my blood pressure is still averaging 100 /73. In unhealthy people who actually have Polycythemia, there is no nitric oxide production and trouble begins. Also as you can see from your blood tests mcv, mch, mchc and platelets are unchanged. I look at it now as an upgrade. You’re enhanced.

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Yeah Dr Rouzier mentioned something about its not actually the HCT that thickens the blood but the platelets.

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Very helpful thanks for braking down what you read. I also have heart the same . It will Level out after a year. I’ll have to find the source. I have heard many times that men on trt have blood or heart issues because it’s hereditary or an underlying cause and trt sped it up. It’s not because trt created the issue. Helps us sleep at night knowing about this false narrative on trt all the news outlets talk about. After all they don’t make money talking about things that are good …
They make money from death; war; drama and destruction.