How long after the T injection are T levels the highest?

[Pacman]

I am asking about all three most common esters: cypionate, enanthate, propionate; because I know that the peak happens all at different times post-inection for all three of those...

Generally speaking, I always do blood tests when my T levels are lowest (the day of my injection before I inject) to see what they are at the lowest point. If let's say I want to see what they are at the highest, how long after my most recent injection should I run bloods?

EXAMPLE: Let's say I am injecting 100 mg of cypionate/enanthate on Wednesday, and then another 100 mg of cypionate/enanthate on the following Sunday -- Will my T levels be elevated on Monday due to Wednesday's injection or Sundays's injection? And if the answer is "both", will Wednesday's injection greatly affect Monday's results?

And one last question. Why are labs run every 3-6 months for T levels? Can't you see right away if T injections shoot up T levels, within just a few days?

 

[Vince Carter]

Im working a series of labs right now to see where I peak on 16mg/D Cyp, and it LOOKS like my peak is ~28hrs post.
@10hrs post my levels are still dropping. I'm about to get a draw to see 12hrs post injection.
I was quite surprised to see my peak was/is many hours later than I ever would have imagined.

 

[sh1973]

My peak with once weekly is days 4-5.

 

[Cataceous]

To get an idea of what's happening with a constant injection cycle, consider injecting a testosterone ester with a half-life of four days that instantly contributes 400 ng/dL to total serum testosterone. Four days later it's contributing 200 ng/dL. Another four days later it's contributing 100, and so on. In this simplified example, the trough testosterone consists of contributions from all the previous injections, going back forever: 200+100+50+25+... This is 400 ng/dl. After the injection you get the peak, which is 800 ng/dL.

In reality there's a delay to the peak serum testosterone after each injection. The length of this delay depends on various factors, with the ester and the length of the injection cycle being among the most important. With daily injections the (small) peaks are probably occurring around 12 hours post-injection. With a longer ester, such as cypionate, and a four-day injection cycle, peaks most likely occur in the range of 24 to 48 hours post-injection.

 

[DragonBits]

Im working a series of labs right now to see where I peak on 16mg/D Cyp, and it LOOKS like my peak is ~28hrs post.
@10hrs post my levels are still dropping. I'm about to get a draw to see 12hrs post injection.
I was quite surprised to see my peak was/is many hours later than I ever would have imagined.

but what levels is your and other's peak at?

I know with Nebido after 16 days my total T went from 350>1380, but after 89 days it has fallen to 690. I don't know what the actual peak day is, to know that I would have to test at least every day after day one.

With 2 clicks of testosterone cream 200 mg it peaks at 1000 in 2.5 hours, but I use DMSO to aid in absorbation. I have no idea what happens without the DMSO nor if that affects trough levels.

Odd how when you first test for testosterone, they want you shoot for get peak levels, when you use a cream the same, shoot for peak levels, when you use testos cypionate you aim for trough level.

 

[Pacman]

Im working a series of labs right now to see where I peak on 16mg/D Cyp, and it LOOKS like my peak is ~28hrs post.
@10hrs post my levels are still dropping. I'm about to get a draw to see 12hrs post injection.
I was quite surprised to see my peak was/is many hours later than I ever would have imagined.

16 mg? Is that a typo?

 

[Systemlord]

16 mg? Is that a typo?

This is a men's health forum where optimal is the goal, daily injections provides very stable levels that are virtually static with almost no decline is levels.

No swings in levels and levels are kept in a tighter range. This is critical for men with low SHBG on the lower end or for those needing estrogen lower and kept in a tighter range for consistent libido and erections.

I do very well on 7-10mg daily, Free T is near the top of the ranges.

 

[Pacman]

To get an idea of what's happening with a constant injection cycle, consider injecting a testosterone ester with a half-life of four days that instantly contributes 400 ng/dL to total serum testosterone. Four days later it's contributing 200 ng/dL. Another four days later it's contributing 100, and so on. In this simplified example, the trough testosterone consists of contributions from all the previous injections, going back forever: 200+100+50+25+... This is 400 ng/dl. After the injection you get the peak, which is 800 ng/dL.

In reality there's a delay to the peak serum testosterone after each injection. The length of this delay depends on various factors, with the ester and the length of the injection cycle being among the most important. With daily injections the (small) peaks are probably occurring around 12 hours post-injection. With a longer ester, such as cypionate, and a four-day injection cycle, peaks most likely occur in the range of 24 to 48 hours post-injection.

That answered my question, thank you sir.

 

[Vince]

Even though I'm not a low shbg guy. I do daily injections, just to keep my levels nice and steady. I know there is some fluctuation, but with daily injections the fluctuations can't be too much?

 

[Pacman]

Excuse my ignorance, but why does low shbg have an influence on injection frequency? I recall having high shbg levels means less free T is around, meaning having "high" levels of T will not matter since your body will not put it to use. Am I misunderstanding how this works?

 

[Systemlord]

Excuse my ignorance, but why does low shbg have an influence on injection frequency?

SHBG binds testosterone, low SHBG men have problems with excreting exogenous T more quickly and tend to metabolize testosterone faster and therefore more often require very frequent injections to keep levels elevated.

I recall having high shbg levels means less free T is around, meaning having "high" levels of T will not matter since your body will not put it to use.

Correct, you will require a higher Total T to overcome high SHBG to have enough Free T in circulation.

 

[Cataceous]

SHBG binds testosterone, low SHBG men have problems with excreting exogenous T more quickly and tend to metabolize testosterone faster and therefore more often require very frequent injections to keep levels elevated.
....

This is a common explanation, but it doesn't quite work with respect to TRT. Suppose you have a guy with high SHBG on TRT with constant testosterone levels from frequent injections. What happens if you suddenly make his SHBG low and change nothing else? I think the surprising answer is that, after a stabilization period, total testosterone drops so that free testosterone matches what it was with high SHBG. The reason why is that the rate of testosterone entering the system from injected depots doesn't change. At steady state the rate that testosterone leaves the system must match what's coming in. I explain the argument with an analogy to two tubs of water in this thread.

 

[Vince Carter]

constant testosterone levels from frequent injections.

You're so wrong.

 

[Cataceous]

You're so wrong.

Do we need to play "20 Questions" to find out why?

In the meantime, I'll give you something specific to disagree with, and illustrate what I meant: I suspect that more than 95% of guys stabilized on daily cypionate injections would have less than 10% intra-day variability in serum testosterone. Even 5% is possible. A rebuttal should not be based on anecdotal evidence.

In addition, relatively constant testosterone is not necessary for what I was saying about SHBG; it just makes it easier to conceptualize.

 

[antelopers]

This is a common explanation, but it doesn't quite work with respect to TRT. Suppose you have a guy with high SHBG on TRT with constant testosterone levels from frequent injections. What happens if you suddenly make his SHBG low and change nothing else? I think the surprising answer is that, after a stabilization period, total testosterone drops so that free testosterone matches what it was with high SHBG. The reason why is that the rate of testosterone entering the system from injected depots doesn't change. At steady state the rate that testosterone leaves the system must match what's coming in. I explain the argument with an analogy to two tubs of water in this thread.

Ok but using your tub of water analogy, assuming low shbg in the bottom bathtub having a bigger drain - whatever is being released into the bottom tub is being expelled very quickly. No matter how much you add to the first bathtub, it will be expelled as soon as it reaches the bottom one if the bottom drain is bigger. It wouldn't hanging around pooling in the bottom at the same rate if the drain was bigger. Which is what injections aim for- a supply of serum testosterone in your system that is bound and then used as it releases from shbg and albumin at a reasonable rate (the bottom drain). So if it's not being bound enough, that means it's expelling too quickly.

The solution then, would be to add multiple bathtubs on the top to increase the amount to saturate the bottom tub until you overcame the speed of the drain, while simultaneously preventing too much unbound t in the system at once which can lead to rapid aromatization. Which would be the equivalent of having multiple smaller depots spaced out on say a daily basis. Another depot starts releasing before bottom tub expels everything from the first.

You can see this from low vs normal shbg guys who test peak and trough. The low shbg guys have a lower trough after their peak and have to compensate by injecting more frequently if they want that total serum T to be as high as someone with low shbg.

That is also assuming that an ester in a Depot has a flat release rate, it doesn't. It's at it's maximum somewhere around 24-48 hours normally if you look at cypionate pharmacokinetics, and then starts dropping off pretty quickly as the surface area of the depot quickly decreases. Again, looking at it this way, if a low shbg guy is expelling the testosterone entering his system quickly, injections every 48 hours would make sense to give the new depot time to release and start rising before the other one falls too much to overcompensate for the fact that what is being released into the bloodstream is rapidly expelled. If they have low shbg, anything being released from the depot is being expelled too quickly to give a more relatively "stable" supply of Testosterone in the blood that naturally unbinds at the rate it would in someone with normal shbg.

 

[sh1973]

I’m not sure where people are getting the info that cypionate has such a short half life. Cypionate has a 8 day half life and most men can still feel pretty decent for 2-3 weeks after their last injection if they’re trying to come off cypionate. I briefly tried every other week dosing in the beginning and at 200mg I was over 1909ng at day 7 and over 800ng at day 14. I personally know an older gentlemen that’s been on this type of dosing for several years and loves it. Point is everyone is different in how they metabolize any drug but an ester like cypionate or enanthate certainly doesn’t need to be injected every day. Sure there are guys that do well dosing this frequently but cypionate hangs around a long time in anyone. Shbg has absolutely nothing to do with the release rate from the depot. Even propionate which I tried for a few weeks doesn’t peak for close to two days.

 

[antelopers]

I’m not sure where people are getting the info that cypionate has such a short half life. Cypionate has a 8 day half life and most men can still feel pretty decent for 2-3 weeks after their last injection if they’re trying to come off cypionate. I briefly tried every other week dosing in the beginning and at 200mg I was over 1909ng at day 7 and over 800ng at day 14. I personally know an older gentlemen that’s been on this type of dosing for several years and loves it. Point is everyone is different in how they metabolize any drug but an ester like cypionate or enanthate certainly doesn’t need to be injected every day. Sure there are guys that do well dosing this frequently but cypionate hangs around a long time in anyone. Shbg has absolutely nothing to do with the release rate from the depot. Even propionate which I tried for a few weeks doesn’t peak for close to two days.

https://anabolic.org/wp-content/uploads/2015/04/testcyp.jpg
https://anabolic.org/wp-content/uploads/2015/04/testprop.jpg

You're making the same logical error as the other poster in assuming that whatever is released from the depot is utilized at the proper rate. If too much is free, it is quickly converted to dht and e2 and expelled. You need a reserve not just from the depot but from your shbg and albumin to release it into the body as free testosterone as needed. See my above post explaining why frequent injections are necessary for those with low shbg, it addresses the question of the depot and how quickly it's utilized once released from the depot.

 

[Cataceous]

Ok but using your tub of water analogy, assuming low shbg in the bottom bathtub having a bigger drain - whatever is being released into the bottom tub is being expelled very quickly. No matter how much you add to the first bathtub, it will be expelled as soon as it reaches the bottom one if the bottom drain is bigger. It wouldn't hanging around pooling in the bottom at the same rate if the drain was bigger. Which is what injections aim for- a supply of serum testosterone in your system that is bound and then used as it releases from shbg and albumin at a reasonable rate (the bottom drain). So if it's not being bound enough, that means it's expelling too quickly.
...

Please read the rest of the other thread. It clears up some of these misconceptions. Most important, these tubs can never drain completely, which is a consequence of having the drain flow proportional to water height and to drain size. There is always going to be a non-zero water height in both tubs. As a result, at steady state we can write:

k * water_height(lower_tub) * drain_size(lower_tub) = flow_rate = constant

which is modeling:

free_T = k1 * total_T * f(SHBG)
k2 * free_T = k3 * total_T * f(SHBG) = MCRT = constant

Making free T linear in total T is an assumption, but models show this to be fairly reasonable at a fixed SHBG. MCRT is the metabolic clearance rate of testosterone. The analogous parameters are:
water_height ~ total_T
drain_size ~ f(SHBG)
flow_rate ~ MCRT

...

You can see this from low vs normal shbg guys who test peak and trough. The low shbg guys have a lower trough after their peak and have to compensate by injecting more frequently if they want that total serum T to be as high as someone with low shbg.
...

Show me the math that makes this possible. You're claiming a change in the effective half-life of testosterone. This will take some extreme gymnastics, because the release of testosterone from the injected depot is the same regardless of SHBG. Somehow, with low SHBG you have to make the MCRT lower with high total T and higher with low total T, which seems completely non-physical.

...
That is also assuming that an ester in a Depot has a flat release rate, it doesn't. It's at it's maximum somewhere around 24-48 hours normally if you look at cypionate pharmacokinetics, and then starts dropping off pretty quickly as the surface area of the depot quickly decreases. Again, looking at it this way, if a low shbg guy is expelling the testosterone entering his system quickly, injections every 48 hours would make sense to give the new depot time to release and start rising before the other one falls too much to overcompensate for the fact that what is being released into the bloodstream is rapidly expelled. If they have low shbg, anything being released from the depot is being expelled too quickly to give a more relatively "stable" supply of Testosterone in the blood that naturally unbinds at the rate it would in someone with normal shbg.

The low-SHBG guys cannot "expel" testosterone more quickly, because the rate is limited by the same slow release from the injected depot. The effect is to lower total testosterone. I have directly observed this myself, having recently crashed SHBG from 30 nMol/L to 10, and find the same dose of testosterone now produces much lower total serum testosterone.

 

[antelopers]

The low-SHBG guys cannot "expel" testosterone more quickly, because the rate is limited by the same slow release from the injected depot. The effect is to lower total testosterone.

It gets converted into dht or e2 more quickly and is therefore expelled. I am no claiming to be an expert, but I honestly think you're the one pulling mental gymnastics here by making claims based on speculation and your n=1 experience. Your analogy is not accurate in the first place because you're completely dismissing the fact that free testosterone after it is released from the 2nd reserve is more important than even the 1st and that time and time again smaller more frequent injections have proven anecdotally and objectively to work by many doctors who are experts in this field and countless patients including those on this board. You're making an extraordinary claim and not using actual evidence to back it up besides a poor analogy using water and bathtubs, which completely neglects physiology, so I defer the burden of proof to you.

 

[Cataceous]

... Cypionate has a 8 day half life and most men can still feel pretty decent for 2-3 weeks after their last injection if they’re trying to come off cypionate. I briefly tried every other week dosing in the beginning and at 200mg I was over 1909ng at day 7 and over 800ng at day 14.

If you run these numbers then you get a half-life of about 5.6 days. This is in line with other research. From what I've seen the 8-day figure is supported only by one Pfizer document that doesn't cite any research. Other research neglects the influence of endogenous testosterone.

@madman — I'm ready to concede the point. The half-life of T cypionate is indeed more like five days, plus or minus.