T Nation

Labcorp vs Quest Lab Results

Hi everyone…I have a general question concerning lab results. I know that different labs have different reference ranges, but do their actual reported numbers vary due to testing factors? The reason I’m asking is because I am about to start TRT and have 2 lab results. My first was ordered by a clinic from Labcorp and my total T was 258. Then I had one a few weeks later ordered by my endo from Quest and it was 450. I did NOTHING different in those 2 weeks (diet, sleep, activity level all the same), and both tests were performed at the same time (around 1pm). Is it possible for total T to almost double in a few weeks without any intervention from me? Or do Labcorp and Quest use different methods for testing and therefore arrive at different results. And is it advisable to always be tested from the same lab or should it not matter? Thanks for any info. I’m new to this and reading everything I can but was unable to find anything on this topic. Apologies if this has already been addressed.

Maybe 1 used the lcms v the eia assay?

Hormones can vary like that.

Maybe you did not sleep that well, stress, etc.

That’s why you need more than 1 test to confirm any of these hormone deficiencies.

And yes try to use the same lab.

Hey, thanks Charlie. I didn’t realize that levels could vary like that over a few weeks. Good to know though. I’ll try and get my labs at the same place going forward. Thank you.

Your levels can vary like that over the course of a day. Hormones are pretty far from static naturally.

Levels fluctuate day to day and should NEVER be in <300 unless an old man. Your blood testing should be done before 10 a.m as levels decline midday and are lower by the evening.

Often I hear men state they feel worse on some days and better on other days, this is because levels are fluctuating where levels are dipping low only part of the time and eventually they will feel bad more often as time goes on as the situation worsens.

Two lab tests are required because you can get two drastically different results as you have seen for yourself. Lab testing is fallible and not perfect.

Yeah, I new that they fluctuated, but not that much. I was almost thinking that the low number was an anomaly, but now that I’ve been thinking about it, that would explain why I’ve been spending my weekends on the couch and not out playing in the yard with my kids (making me feel like a bad father and guilty and further contributing to my crappy mood). I’m praying that trt will turn things around, or at least send me in a better direction. Thanks guys!

This all is dependant on the skill of your doctor, injections every 2 weeks is commonly prescribed by doctors and is doomed to failure.

I agree. I just came back from my endo, who prescribed me 50 mg weekly Subq. I asked about more frequent injections and she said that would cause too high of a hematocrit level and all sorts of side effects. My understanding is that lower more frequent doses would cause LESS side effects. I almost feel like I know more than she does as I have been spending at least an hour each day reading up on this. I didn’t feel like arguing with her because she was very adamant. Here are my most recent labs. Does her protocol seem ok? Im just starting out with this and was actually thinking shed start me off on something like 50mg twice a week. Thanks for taking the time to read this.

50 mg weekly is worse than doing nothing. It will possibly make your T lower. You should be at a minimum of 100 mg a week. Every body is a little different, but at 185 mg / week my total T is only 671 ng/dl

This is not good. You will not be happy. With your current levels, I’d start you with 150mg a week, if you want to split them up, that would be fine too, but 150mg a week.

Thanks guys…yeah I didn’t have a lot of confidence in her. And I would be her first patient using Subq. I’m all set with being her experiment. I have been speaking with a clinic who said that they’d start me out 2x week IM. They haven’t stated how much, but at this point I will be going to the clinic, where they actually do this for a living. Appreciate the responses!

Sounds more like a belief than actual fact, funny how doctors never having tried it before can say these things. My HCT injecting daily was <45% and EOD was 50% with virtually the same levels. It’s because I was using less testosterone to achieve the same levels and didn’t have to overcompensate for drops in levels with more testosterone between injections.

This is saying, I don’t do TRT often. Your doctors dosing is outside the norms, if we base our decisions on the current guidelines 200mg every 2 weeks, then logic dictates 100mg weekly.

Everyone here knows how this will end, so stop the experiment now and do what you’re eventually going to do anyway, skip the step that involves androgen deprivation and seek competent care.

Good call. Experience matters.

Why do guys come here and read for hours then accept a 50mg protocol and not just walk out of the office?



Hi Jimmy. Understood. I’ve been fortunate that I’ve never had a serious medical issue (besides this one) and my interactions with doctors have been pretty much limited to annual physicals. Myself and I’m sure others have been conditioned over our lifetimes to believe that we should listen to the doctor and that they know what is right. I know logically that this is not always the case - especially after reading everything on this forum, but still I think there was a shred of something in the back of my mind that said “Well, they ARE a doctor after all.” I am past that point now and am now taking control of my own health as you all are. And I am looking forward to being part of this community. Thanks guys.