ZRT Blood spot tests. Accurate at all? Experiences?

[Billegitimate]

When I started TRT, I was totally freaked out by needles. I did ZRT saliva tests initially to get free T. Tracked it while I did all I could to bring up my levels, and finally gave up. Did cream and continued to test and got some very crazy numbers. Way higher, way lower...all over.

Eventually manned up enough to do the blood spot tests. I had a few tests that correlated with what I was feeling, but then others that seemed to be totally anomalous. Every time I got a high reading from ZRT I reduced the cream dosage. Then I'd get really low readings (and feel low as well) and then to be sure I'd do another and get really high.

After much reading I became convinced I was contaminating my skin in some way with T cream prior to the tests. So I was SUPER careful to not have a chance to do that, and did two more tests. One was super low, the other super high (like 10,000 total T). It was all of this that finally convinced me to work on my fear of needles (remember it took me months to get to whee I could do the finger prick) and get bloodwork. I stopped the T cream altogether, waited 3 weeks...3 miserable weeks...and got bloodwork done. Those labs showed my total under 300 where the bottom range was right around 300, and my free T was below the bottom.

So starting on the sub-q test cypionate and I have about 4 boxes of ZRT tests left. I still hate needles and getting blood drawn, so I decided to do one and see what I'd find out.

Got my results, and this is a week and a half into 120mg/week with 180 the first week to load.

E2 43 pg/mL 12-56
Total T 2886 ng/dL 400-1200

The T is flagged as "High"

Yeah, ya think?

So now there's no chance T cream on my skin influence this test like it could have those other times. I feel good, but sheesh, with total T around 600 I was driven and libidinous. With 2886 I am certain I'd be pulling over every time I drove past a fence post with a missing knothole in it.

So, it seems I have more than enough information to think that these results are ridiculous, but I'm just wanting to double check. Do any of you have any experience with ZRT and their blood spot tests? I can see how the saliva tests can perhaps measure free T, but it sure is looking like the blood spot tests aren't accurate at all.

For what it's worth, this is the motivation I need to just go get blood drawn every time I'm curious. The female hormone panel is less than $70 from privatemdlabs, and I have a Labcorp about 2 minutes away. Next time I do that, I'll drive straight home and do one of the ZRT kits as well, so I have samples within 10 minutes of each other and I'll report on what they each say. I'll do that with all the ZRT kits I have left.

I so hate not knowing. If the guy who made the first glucometer would just whip up a nice testometer I'd be first in line to buy.

Anyway, anyone out there confirmed or debunked the ZRT stuff?

 

[Megatron28]

I think you just did. It is highly unlikely those results are correct on your current dose of test. But do the comparison the next few times and let's see.

Congrats on getting over your fear of needles!

 

[TheChosenOne]

Keep us posted on your results. It would be nice to have a quick, cheap test to do at home. But what good is it if it's not accurate. I always use privatemdlabs. Very pleased with them, easy and accurate.

 

[Billegitimate]

I had blood drawn at Labcorp yesterday and went straight home and did a ZRT test kit for T and E2. I already have the Labcorp numbers, less than 24 hours later, so that right there is argument enough not to use the ZRT approach for me, but I'll see what I get back in a week from ZRT and will post an update with the comparison.

FWIW, my Labcorp numbers:
Total T: 1062 (348-1197)
E2: 29.5 (7.6-42.6)

CBC numbers and everything else all in range. Hematocrit 45.2

This was the day after my last twice weekly shot, so I suppose it is a peak measurement, but with sub-q and twice weekly I doubt there are large swings either way.

 

[TheChosenOne]

Those numbers are definitely more realistic on 120 mg.

 

[Megatron28]

I had blood drawn at Labcorp yesterday and went straight home and did a ZRT test kit for T and E2. I already have the Labcorp numbers, less than 24 hours later, so that right there is argument enough not to use the ZRT approach for me, but I'll see what I get back in a week from ZRT and will post an update with the comparison.

FWIW, my Labcorp numbers:
Total T: 1062 (348-1197)
E2: 29.5 (7.6-42.6)

CBC numbers and everything else all in range. Hematocrit 45.2

This was the day after my last twice weekly shot, so I suppose it is a peak measurement, but with sub-q and twice weekly I doubt there are large swings either way.

You may want to get the sensitive estradiol lab next time. Your E2 may be a little on the low side. The regular assay is often 10-20 points overstated.

 

[Billegitimate]

Megatron, I'm not taking any AI. So if it is low...options are add HCG, or bump the Testosterone dosage? I suppose option 3 is get really REALLY fat, but I'll definitely pass on that one.

 

[Megatron28]

I would go with what's behind door #1.

 

[Billegitimate]

Heh. Keep in mind this test was done just days after that Elton John concert. I was surprised to see it within range. LOL at myself!

On a more serious note, does the sensitive test result in a different degree of accuracy at the lower levels only? So if the regular test puts me at 29 on a 7-42 range, the sensitive test might show that it's really 20, but it's not ever going to show a higher number?

I don't know why I'm having a hard time phrasing this question, but that didn't seem very clear.

I've seen people test high on a regular test, and usually the recommendation is to start an AI, because high on any test is high. But when it's lower, the recommendation becomes do the sensitive test. I'm inferring from that that the sensitive test may reveal you're lower if you're low already, but it won't reveal you're higher when the normal test says you're low.

That's the inference that I'm questioning. Am I accurate in that thinking?

 

[Megatron28]

Heh. Keep in mind this test was done just days after that Elton John concert. I was surprised to see it within range. LOL at myself!

On a more serious note, does the sensitive test result in a different degree of accuracy at the lower levels only? So if the regular test puts me at 29 on a 7-42 range, the sensitive test might show that it's really 20, but it's not ever going to show a higher number?

I don't know why I'm having a hard time phrasing this question, but that didn't seem very clear.

I've seen people test high on a regular test, and usually the recommendation is to start an AI, because high on any test is high. But when it's lower, the recommendation becomes do the sensitive test. I'm inferring from that that the sensitive test may reveal you're lower if you're low already, but it won't reveal you're higher when the normal test says you're low.

That's the inference that I'm questioning. Am I accurate in that thinking?

The regular assay is less accurate at low E2 levels. It does just fine measuring high levels.

We have seen cases where the regular assay comes in lower than the sensitive assay. It isn't as common but it has happened.