T Nation

Hold Off T Injection/Thyroid Before Labs? Interpreting Labs Based on Timing/Reference Ranges?

Trying to get a consensus here. One provider had me doing T injections 2x per week, and didn’t strongly encourage timing getting my labs taken anytime specifically, but when asked said something to the effect of “if you’re injecting every 3.5 days, you may want to get labs taken in after 3 days have passed since your last injection.” For thyroid, they didn’t say anything specific, but during my last consult since I said I took thyroid the morning of labs, they said “maybe next time, get labs without taking the morning thyroid dose to see how the labs come out.”

The other provider I spoke to said they encourage injecting at least every other day, if not everyday. They also said that testosterone levels would be inflated unless I waited 6 days since my last injection before getting labs taken. For thyroid, they said to not take any thyroid medication at least 12 hours prior to labs.

Is there a consensus on this? I have had labs taken under both instructions, and the numbers were quite different. Below are the numbers:

With T innjection 3 day prior, and Thyroid med taken the morning of labs. NOTE: This is confusing because this was a labcorp lab, while the second one was a quest lab. Reference ranges are different on the Free T.

Free T - 41.9pg/ml (8.7-25.1pg/ml)
Free T3 - 4.7 (2.0-4.4pg/ml)
(Free T4 not taken)


Labs with last T injection taken 6 days prior, and last thyroid med taken ~18 hours prior. (This was a Quest lab. Different reference ranges):

Free T - 101.7pg/ml (46-224pg/ml)
Free T3 - 3.0 (2.3-4.2pg/ml)
Free T4 - 0.8 (0.8-1.8ng/ml)

From the consults on the two providers, they were pretty similar as far as T injections moving forward as far as weekly amount, increasing it slightly, and that it would take time with my high SHBG to see improvement. For thyroid, the first provider was going to keep it the same (2grains armour + 30mcg Cytomel). The second provider increased it to (2.5 grains armour + 50mcg cytomel). So far, a week into the increased thyroid, I’m feeling good. My heart rate runs higher when working out now, but I’d say not excessive. Before, my heart rate always ran very low, even during submaximal exercise. I was also noticing HR running higher since startinng T injections, but again, not excessive.

Trying to get a consensus here on what most people do with their protocol prior to taking labs, and how that should impact how labs are determined. From above labs, you can see taking my thyroid the morning of has my T3 at the top of the range, while taking labs 18 hours after taking thyroid has me just in the middle of the range.

Any advice on either of these things? Do people generally hold off T injections before getting labs taken? Same for thyroid medication? Also, what is a more ideal free testosterone number with Quest lab reference ranges?

Labs are usually requested on the day of the injection, prior to it. Waiting six days without an injections on and every other day schedule makes no sense.

Thyroid levels are checked a couple of hours after taking it. On occasion, they are checked early to mid afternoon.

If going solely off a number, closer to 200 as most feel better at the higher end of the range.