Peak vs trough testosterone level

sh1973 · 2025-10-22T06:36:56-0500

Have there ever been any large studies that give an accurate range of what a typical range/percentage there is between the low and high points of a testosterone injection. For instance, I have always did best with once weekly low dose and currently do 52mg per week. My trough has been 640-660ng day seven morning of my next shot. I would like to know where I’m peaking and most likely just need to get labs but was curious if there is a range verified through studies? At one point I checked levels when doing 100mg per week and 3 days after injection I was close to 1500ng. At 100mg my trough was over 1000ng.

WhiteMale · 2025-10-22T07:05:12-0500

Ive often thought and believed that peak over trough is where we should be looking. Its a flaw in how TRT is sold to guys as in we'll keep you at the LOWEST point high physiological if not supraphysiological.
Most guys with E problems, which is most all, usually overlook the fact that their number of 29 on a LCMSMS test, which by the numbers looks good and they can't understand why they still have E symptoms and problems.

sh1973 · 2025-10-22T07:17:50-0500

WhiteMale said:
Ive often thought and believed that peak over trough is where we should be looking. Its a flaw in how TRT is sold to guys as in we'll keep you at the LOWEST point high physiological if not supraphysiological.
Most guys with E problems, which is most all, usually overlook the fact that their number of 29 on a LCMSMS test, which by the numbers looks good and they can't understand why they still have E symptoms and problems.

I agree and honestly think labs midway would be a better window to see what’s happening.

Cataceous · 2025-10-22T08:44:33-0500

You can estimate the peak-trough ratio based on the half-life of the testosterone ester. The estimate I use for weekly injections of testosterone cypionate is 2.5, which stems from a five-day half-life. This would put your peak at over 1,500 ng/dL. However, half-lives vary among individuals, so yours could be longer—meaning slower absorption—yielding less dramatic peaks. This is supported by your report of a drop from 1,500 ng/dL to ~1,000 ng/dL in about four days. These numbers put your half-life closer to seven days, and would reduce your predicted peak to more like 1,300 ng/dL. Your relatively high SHBG means these numbers for total testosterone are not as extreme as people might think. For example, with TT at 1,300 ng/dL and SHBG at 60 nMol/L your Vermeulen calculated free testosterone is about 23 ng/dL, which is close to the top of the healthy normal range for young men. A trough TT of 650 ng/dL puts cFTV at around 10 ng/dL, which is high enough to avoid being hypogonadal.

sh1973 · 2025-10-22T13:41:07-0500

Cataceous said:
You can estimate the peak-trough ratio based on the half-life of the testosterone ester. The estimate I use for weekly injections of testosterone cypionate is 2.5, which stems from a five-day half-life. This would put your peak at over 1,500 ng/dL. However, half-lives vary among individuals, so yours could be longer—meaning slower absorption—yielding less dramatic peaks. This is supported by your report of a drop from 1,500 ng/dL to ~1,000 ng/dL in about four days. These numbers put your half-life closer to seven days, and would reduce your predicted peak to more like 1,300 ng/dL. Your relatively high SHBG means these numbers for total testosterone are not as extreme as people might think. For example, with TT at 1,300 ng/dL and SHBG at 60 nMol/L your Vermeulen calculated free testosterone is about 23 ng/dL, which is close to the top of the healthy normal range for young men. A trough TT of 650 ng/dL puts cFTV at around 10 ng/dL, which is high enough to avoid being hypogonadal.

At some point I would like to get labs 2-3 times during the week to see where things are. It would be interesting.

madman · 2025-10-22T17:11:22-0500

sh1973 said:
Have there ever been any large studies that give an accurate range of what a typical range/percentage there is between the low and high points of a testosterone injection. For instance, I have always did best with once weekly low dose and currently do 52mg per week. My trough has been 640-660ng day seven morning of my next shot. I would like to know where I’m peaking and most likely just need to get labs but was curious if there is a range verified through studies? At one point I checked levels when doing 100mg per week and 3 days after injection I was close to 1500ng. At 100mg my trough was over 1000ng.

Would not get too caught up on the PKs!

Post in thread 'Anyone have examples of TRT pharmacokinetic charts?'

Sep 21, 2025

anol1258 said:
Has anyone seen visual charts showing how testosterone levels change between TRT injections?
I'm curious whether the curves are smooth or if there are sharp peaks/drops, especially for the common esters like cypionate and enanthate.

Just looking to see what the typical pharmacokinetic profile looks like visually.

I found this post, but would like some more examples if available!:

Pharmacokinetic Profile of Subcutaneous Testosterone - Excel Male Health Forum

Regarding half-lives keep in mind that a majority of studies on the PK/PD of the various T-esters were done using IM...

Thread 'Variance in Peak and Trough T Levels in Men Using Intramuscular T Injections'

Aug 20, 2018

MP85-14 VARIANCE IN PEAK AND TROUGH TESTOSTERONE LEVELS IN MEN USING INTRAMUSCULAR TESTOSTERONE
Bruno Nascimento*, Helen L Bernie, Elizabeth Schofield, John P. Mulhall, New York, NY

INTRODUCTION AND OBJECTIVES

In men using intramuscular testosterone (IM T), clinical experience shows us that, despite stable dosing and frequency, total testosterone peak (Tp) and trough (Tt) levels are highly variable, thus challenging the clinician to make a decision regarding dose adjustments. The goal of this study was to define...

MP85-14 VARIANCE IN PEAK AND TROUGH TESTOSTERONE LEVELS IN MEN USING INTRAMUSCULAR TESTOSTERONE
Bruno Nascimento*, Helen L Bernie, Elizabeth Schofield, John P. Mulhall, New York, NY

CONCLUSIONS

In our population of patients on stable IM T dose, there was a wide mean variation in both Tp (23%) and Tt (17.5%). In addition to that, 25% of patients had a maximum Tp change greater than 50% and a maximum Tt change greater than 35%. Clinicians should be aware of this high variability in levels when deciding on dose adjustment.

madman · 2025-10-22T17:20:26-0500

Cataceous said:
You can estimate the peak-trough ratio based on the half-life of the testosterone ester. The estimate I use for weekly injections of testosterone cypionate is 2.5, which stems from a five-day half-life. This would put your peak at over 1,500 ng/dL. However, half-lives vary among individuals, so yours could be longer—meaning slower absorption—yielding less dramatic peaks. This is supported by your report of a drop from 1,500 ng/dL to ~1,000 ng/dL in about four days. These numbers put your half-life closer to seven days, and would reduce your predicted peak to more like 1,300 ng/dL. Your relatively high SHBG means these numbers for total testosterone are not as extreme as people might think. For example, with TT at 1,300 ng/dL and SHBG at 60 nMol/L your Vermeulen calculated free testosterone is about 23 ng/dL, which is close to the top of the healthy normal range for young men. A trough TT of 650 ng/dL puts cFTV at around 10 ng/dL, which is high enough to avoid being hypogonadal.

Shit kicker here is he was still hitting a high FT 23.9 ng/dL with a trough TT 855 ng/dL and this is with high SHBG 66 nmoL/L.

His FT was tested using the most accurate assay Equilibrium Dialysis!

When he was hitting a trough TT 650 ng/dL with high SHBG he was still hitting a high trough FT 18 ng/dL.

He stated the his FT was tested numerous times using the same assay and even with a robust trough TT and high SHBG his trough FT is high.

S

Thread 'TRT Dose question'

Jul 20, 2025

For those that have known me over the years know that in the past, I definitely had my struggles with TRT and I’ve tried pretty much everything there is to try. I have now been on TRT the better part of 16 years and for the last several years, I’ve been using 60 mg once per week of testosterone cypionate. This has been via the intramuscular route. This normally puts my seven day low point somewhere between 700–750ng. Even if it’s overdose, I still have the phenomenon a feeling sort of bad the day after the injection and always feeling the best to wear the end of the week. This has been...

https://www.mayocliniclabs.com/test-notifications/attachment.php?id=73010

TESTOSTERONE, FREE

Males (adult):

20-<25 years: 5.25-20.7 ng/dL

25-<30 years: 5.05-19.8 ng/dL

30-<35 years: 4.85-19.0 ng/dL

35-<40 years: 4.65-18.1 ng/dL

40-<45 years: 4.46-17.1 ng