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dr.Stack
07-04-2010, 05:59 PM
An important consideration when planning a steroid cycle, in particular the timing of dosing to be administered, is the active half-life of the drug being employed. The half-life may be defined as the time (t) the level is half of the starting level of a given compound; at time 2t, the level is a quarter of the starting level, and at time 3t, the level is an eighth of the starting level, and so on.

This information is vital in the timing of the dosing when attempting to achieve a more stable blood concentration, which leads to greater overall results and maintenance of gains. Some fluctuations of concentration levels are acceptable, and are also mostly unavoidable, but should be kept to a minimum.

This article covers the half-life's of the most commonly used steroids, esters and ancillary compounds.

Oral steroids

Drug Active half-life
Anadrol / Anapolan50 (oxymetholone) 8 to 9 hours
Anavar (oxandrolone) 9 hours
Dianabol (methandrostenolone, methandienone) 4.5 to 6 hours
Methyltestosterone 4 days
Winstrol (stanozolol)
(tablets or depot taken orally) 9 hours
Steroid esters

The half-life applies to the ester regardless of hormone attached, for example trenbolone enanthate and primobolan (methenolone enanthate) will act very similarly to testosterone enanthate in terms of release rate.

Drug Active half-life

Suspension within 1 hour
Acetate 1 day
Propionate 1 day
Phenylpropionate 1-2 days
Butyrate 2-3 days
Valerate 3 days
Hexanoate 3 days
Caproate 4-5 days
Isocaproate 4-5 days
Heptanoate 5-6 days
Enanthate 5-6 days
Octanoate 6-7 days
Cypionate 6-7 days
Nonanoate 7 days
Decanoate 7-8 days
Undeclenate 8-9 days
Undecanoate Approx 20 days

Ancillaries

Drug Active half-life
Arimidex 3 days
Clenbuterol 1.5 days
Clomid 5 days
Cytadren 6 hours
Ephedrine 6 hours
T3 10 hours

sixteentons
03-04-2011, 01:42 AM
Very useful info.

goanywhere
03-16-2011, 02:30 PM
Very useful info.

I agree - and interesting.

RonnyT
03-16-2011, 06:17 PM
Not to want to know better but completely unscientific. You can find these charts all over the net. It could be true, providing all these active ingredients where compounded in the same oil -solvents - co-solvents -preservatives. Look at this study and I have many more a university in Sweden does very good research to optimal carriers/pharmacokenetics/drugdelivery

Objective:
In the search for long-acting testosterone preparations suited for substitution therapy of hypogonadal men, testosterone undecanoate (TU) dissolved in either tea seed oil or castor oil was investigated.
Design:
* In study I, 1000 mg TU in tea seed oil (125 mg/ml) were injected in equal parts into the gluteal muscles of seven hypogonadal men.
* In study II, 1000mg TU in castor oil (250 mg/ml) were injected
into one gluteal muscle of 14 patients.
Results:
In comparison with published data on testosterone enanthate, most widely used for i.m. injections, the kinetic profiles of both TU preparations showed extended half-lives and serum levels not exceeding the upper limit of normal.
The TU-castor oil preparation had a longer half-life than TU in tea
seed oil 34 vs 21 days
European Journal of Endocrinology 140 414–419

RonnyT
03-16-2011, 06:29 PM
To explain in short:
in the chart approx. 20 days
testosterone undecanoate in tea seed oil had a half life of 21 days
testosterone undecanoate in castor oil had a half life of 34 days

This study was done in respect to MENT. They want means that stay stable for a long time and injection intervals as long as possible. Thats also why long ago Sustanon was created for hormone replacement.

RonnyT
03-16-2011, 06:45 PM
We also have to concidder the volume (cq dosis) and the injectionspot.
The dissapearence rate of nandrolone decanoate in human males.
If you're really interested I can post more about this subject..

goanywhere
03-16-2011, 08:23 PM
I find it interesting and always want to learn more. I don't know about anyone else.

dino
03-17-2011, 05:36 AM
We also have to concidder the volume (cq dosis) and the injectionspot.
The dissapearence rate of nandrolone decanoate in human males.
If you're really interested I can post more about this subject..

The study of your graphic: http://jpet.aspetjournals.org/content/281/1/93.full

RonnyT
03-17-2011, 04:47 PM
Yep and you can download the whole study here http://www.eje-online.org/cgi/content/abstract/140/5/414 the pdf on the right side of the page.

RonnyT
03-17-2011, 04:55 PM
http://www.ncbi.nlm.nih.gov/pubmed/12954670


This study (on monkeys) showed that 100 mg Testosteron Undecanoate (100 mg pure testosterone base, thus without the esterweight) was (at least) 2,5times as effective as 100 mg Testosterone Enanthate. Which means that this study proved that the estrification has a definite influence on the bioavailability

Pharmacokinetics and degree of aromatization rather than total dose of different preparations determine the effects of testosterone: a nonhuman primate study in Macaca fascicularis.
Weinbauer GF, Partsch CJ, Zitzmann M, Schlatt S, Nieschlag E.
Institute of Reproductive Medicine of the University, Domagkstrasse 11, D-48129 M?nster, Germany.
Abstract
Currently available testosterone (T) preparations differ substantially in their pharmacokinetic profile that might influence their androgenic properties in terms of suppression of the gonadal axis, effects on anabolic parameters, lipid metabolism, and erythropoiesis. The present work was undertaken to determine the physiological effects of three T preparations with different serum kinetics. Twenty adult male cynomolgus monkeys (Macaca fascicularis) were randomly assigned to receive treatment for 28 weeks with either T enanthate (TE) every 4 weeks, T buciclate (TB) every 7 weeks, or T undecanoate (TU) every 10 weeks or remaining untreated (controls). Each injection delivered 20 mg pure T per kilogram body weight. Pharmacokinetic profiles demonstrated higher peak levels of T for TE-treated animals; serum half-lives were longer for TU or TB. Estradiol levels (area under the curve) were significantly higher in TB vs TU or TE. All T regimens suppressed serum luteinizing hormone bioactivity and testicular volumes declined (all P <.001 vs controls). Sperm counts were markedly lowered in all animals but least in TE (P <.01 vs TB or TU). During recovery phase, return to normal for all three parameters occurred significantly earlier in TE-treated animals, followed by those given TU, compared with TB (all P <.001 between groups). Body weight increased significantly during T exposure. This effect was stronger and more sustained in TB vs TU or TE (both P <.001). Serum creatinine and hemoglobin increased with high significance in all T-treated animals (all P <.001 vs controls). The lowering impact of T on serum lipids was markedly stronger in the longer-acting T preparations in comparison with TE, as were effects on purine metabolism (all P <.001). The pattern of exposure and degree of aromatization rather than overall exposure to T determine its effects in the preclinical primate model. Both fluctuations of androgen concentrations and the conversion rate to estradiol influence gonadal suppression as well as metabolism. These results have to be considered in men receiving treatment for hypogonadism or regimens for hormonal contraception.

iamready
03-17-2011, 08:03 PM
I have read over the net that cyp and enanth could actually have a half life of3-4 days.. and others say10 days. How do we know which are right

goanywhere
03-17-2011, 08:27 PM
Interesting. A lot of it was over my head. Thank you Dino and Ronny.

Simple me was trying to learn about half life's - but I think you point is - it depends on lots of factors so there is no hard and fast rule or one-size-fits all.

Things that can make a difference:

1. Injection Site

2. What T is mixed with (caster oil vs tea oil)

Even the amount of estrogen varies by compound. Think I will try to avoid TB.

Bo Deen
03-17-2011, 08:28 PM
DIfferent way of coming at it, but the data I've seen on cypionate suggest that the body metabolizes 9% of your dose each 24 hours. I understand that enanthate isn't much different. It would work out to a half-life consistent with one of the earlier posts.

goanywhere
03-17-2011, 08:31 PM
I have read over the net that cyp and enanth could actually have a half life of3-4 days.. and others say10 days. How do we know which are right

If memory serves me - I had heard 8 days for cyp. Which is right in line with 6-7 days above. If my understanding of the articles here is fair - it can also vary by Mfg. as their base or what they are mixing with can vary.

goanywhere
03-17-2011, 11:10 PM
Are the half lifes measured here for bound T? Free T? Or total? In my simple understanding - bound is useless. Free is what counts.

SAFELIFE1
03-18-2011, 02:27 AM
Yep and you can download the whole study here http://www.eje-online.org/cgi/content/abstract/140/5/414 the pdf on the right side of the page.

Thanks RT. Good info.

RonnyT
03-18-2011, 10:06 AM
Volume and Concentration

Steroids come in all shapes and sizes. In other words, you can find nandrolone (or Testosterone or boldenone) esters in 25 mg/ml, 50 mg/ml, 100 mg/ml, 200 mg/ml and so forth. Is a 400 mg injection using two milliliters of a 200 mg/ml oily solution the same as using four milliliters of a 100 mg/ml solution? After all, the net amount is still 400 mg, right? Unfortunately, this isn?t the case.

Steroid concentration in the solution greatly affects the dynamics and kinetics. In this study, some of the men received a 100 mg/ml injection of nandrolone decanoate and other men received a 100 mg injection using a 25 mg/ml solution (which means they received four milliliters, of course). Those that received the 100 mg/ml injection reached significantly higher (between 30% and 50%) plasma levels of nandrolone than those who got 100 mg via the 25 mg/ml solution. To top it off, the 100 mg/ml group?s plasma nandrolone level stayed elevated for a little bit longer; however, the length of suppression of endogenous Testosterone was almost identical.

What does this tell us? It tells us that if we want to maximize plasma levels of hormone (and thereby, maximize gains in lean muscle) we want to opt for the most concentrated version of whatever steroid(s) we decide we?re going to use. If we?re using Testosterone, we surely want to use a 200mg/ml enanthate over something like 100mg enanthate. If we?re using nandrolone, we want to use 300mg/ml stuff over 50mg/ml or 100mg/ml nandrolone decanoate made by others.


Injections Sites

Another thing that superficially seems trivial but makes a huge difference in plasma steroid concentrations is where you inject. That?s right, this seems utterly trivial but this study concluded that gluteal injections yielded far superior plasma levels as opposed to injections in the deltoid.

Of all the locations that nandrolone injections were given in this study (100 mg/ml x 1 ml in the glutes, 25 mg/ml x 4 ml in the glutes and 100 mg/ml x 1 ml in the deltoid), the deltoid injections yielded the lowest plasma levels of nandrolone by a huge factor, with peak concentrations being 50% lower than the 100 mg/ml gluteal injection and around 10% lower than the 100 mg/ml x 4ml gluteal injection. Lesson learned here: Only inject in the glutes for maximal steroidal efficacy.

Reference

The Journal of Pharmacology And Experimental Therapeutics, Vol 281, No. 1; 93-102, 1997.
http://jpet.aspetjournals.org/cgi/reprint/281/1/93.pdf


If you watch the disappearence rate of sesame you can think how it will influence quickly diappearing short estrifications like by example propionate.

RonnyT
03-18-2011, 10:08 AM
From the point of view of their chemical nature, these solvents can be divided into six groups;

1) monohydric alcohols (ethanol)
2) polyhydric alcohols (propylene glycol, butylenes glycol, glycerol)
3) ethers (poluoxuthylene glycols, glycol mono-ethyl ether)
4) esters (methyl or ethyl oleate, benzyl benzoate, isopropyl myristate)
5) amides (N-methylacetamide, dimethylacetamide)
6) vegetable oils (olive oil, peach oil, etc.)

Of all the nonaqueous solvents, vegetable oils, ethyl oleate, propylene glycol, and polyethyleneglycios with molecular weights of 300 and 400 have the greatest practical value. Apart from water vegetable oils are the solvents most frequently used.

In our domestic pharmaceutical chemical factories. Non-drying fatty oils ? peach and olive oils, consisting of mixtures of glycerides of various high-molecular-weight acids ? are used for the production of millions of ampoules with solutions of various hormone preparations, camphor and vitamins. These oils posses a number of disadvantages: they are not very well absorbed and they rapidly become rancid, forming peroxides and aldehydes which may lead tot the inactivation of the active substance. Oily solutions posses a high viscosity (up to 90 cP), in consequence of which their administration and injection is difficult, particularly in the winter period when the preparation must be warmed before injection. For the same long time to be resorbed in the tissues of the organism, forming infiltrations and oleogranulomas. The formation of oleogranulomas leads to a weakening of the resorption properties of the fatty tissues, a change in overall reactivity of the organism, and a local allergic state of the tissues. The presence in the oils of solid glycerides of stearic and palmitic be dissolved only by heating. It must be mentioned that vegetable oils are used mainly for intramuscular injections and fairly rarely for subcutaneous injections.

iamready
03-18-2011, 10:33 AM
So higher concentration produces better results. Which oils have what effect? Like mtc compared to eo or other oils? Does mtc oil release the hormone quicker or slower?

goanywhere
03-18-2011, 02:18 PM
Great job Ronny. What steps can be taken to avoid the oils becoming stale and rancid? I do believe I have had that happen recently.

Would it help to keep it refrigerated or at least in a cooler place?

stumpy
03-19-2011, 08:50 AM
Great posts Ronny.

RonnyT
03-20-2011, 08:06 AM
Yes , you should store AAS cool in out of light to prevent it from loosing strenghth, low temperature also prevents decomposition etc _ waterbased steoids are even more prone to this. Synthetic oils are better and more constistant, Eo by example only has one fatty acid (C18.1 oleic acid). A lower viscosity gives a greater injectiondepot and allows a quicker disapearence. As discussed here the injectionspot and the doses are important too.

For this reason Geneza uses an (expensive) synthetic oil for its injectables..

In this study: http://ajpendo.physiology.org/content/281/6/E1172.full you'll see that a higher dose of testosterone yields better results on muscle mass and the side-effects are (very) low.


...reading back the text I just assumed you all where healty young men ;-)

RonnyT
03-20-2011, 09:06 AM
I promised that I would post some release rates once in my week-end house.
I made them when working for BodyPage thus they are in the Dutch language.

translation:
Dit zijn de milligrammen testosteron zoals die aan het bloedplasma worden afgestaan in de eerste 24 uur an een eenmalige injectie van Sustanon 250
These are the milligrams of testosterone as released to the blood plasma in the first 24 hours after a single injection of Sustanon 250
halve waardetijd = half life
dag = day
meting 1 = messuring 1

RonnyT
03-20-2011, 09:15 AM
As I found out in posting about the subject, we have many older members, just like me.

Thus to balance after ...in healthy young men .. ..now what happens with healthy older men??? :cool:

Older Men are as Responsive as Young Men to the Anabolic Effects of Graded Doses of Testosterone on the Skeletal Muscle.

Bhasin S, Woodhouse L, Casaburi R, Singh AB, Phong Mac R, Lee M, Yarasheski KE, Sinha-Hikim I, Dzekov C, Dzekov J, Magliano L, Storer TW.

Division of Endocrinology, Metabolism, and Molecular Medicine, Charles R. Drew University of Medicine and Science, Los Angeles, CA 90059; Division of Respiratory Diseases, Pulmonary Physiology, and Critical Care Medicine, Harbor-UCLA Medical Center, Torrance, CA 90502; Laboratory for Exercise Science, El Camino College, Torrance, CA; Division of Endocrinology, Metabolism, & Lipid Research, Washington University School of Medicine, St. Louis, MO 63110 01-1184 Version 3.

Although testosterone levels and muscle mass decline with age, many older men have serum testosterone level in the normal range, leading to speculation whether older men are less sensitive to testosterone. We determined the responsiveness of androgen-dependent outcomes to graded testosterone doses in older men, and compared it to that of young men. The participants in this randomized, double-blind, trial were 60 ambulatory, healthy, older men, 60-75 yr of age, who had normal serum testosterone levels. Their responses to graded doses of testosterone were compared with previous data in 61, 19-35 yr old men. The participants received a long-acting GnRH agonist to suppress endogenous testosterone production and 25, 50, 125, 300, or 600 mg testosterone enanthate weekly for 20 weeks. Fat free (FFM) and fat mass, muscle strength, sexual function, mood, visuospatial cognition, hormone levels, and safety measures were evaluated before, during and after treatment. Of 60 older men who were randomized, 52 completed the study. After adjusting for testosterone dose, changes in serum total testosterone (change -6.8, -1.9, +16.1, +49.5, and +101.9 nmol/L, at 25, 50, 125, 300 at 600 mg*wk(-1), respectively) and hemoglobin (change -3.6, +9.9, +20.9, +12.6, +29.4 g/L at 25, 50, 125, 300, and 600 mg*wk(-1), respectively) levels were dose-related in older men and significantly greater in older men than young men (each P < 0.0001). The changes in FFM (-0.3, +1.7, +4.2, +5.6, +7.3 kg, respectively in five ascending dose groups) and muscle strength in older men were correlated with testosterone dose and concentrations, and were not significantly different in young and older men. Changes in fat mass correlated inversely with testosterone dose (r0.54, P < 0.001) and were significantly different in young and older men (P < 0.0001); young men receiving 25 and 50 mg doses gained more fat mass than older men (P < 0.0001). Sexual function, mood, and visuospatial cognition did not change significantly in either group. Frequency of hematocrit >54%, leg edema, and prostate events was numerically higher in older men than in young men. Conclusion. Older men are as responsive as young men to testosterone's anabolic effects; however, older men have lower testosterone clearance rates, higher increments in hemoglobin, and a higher frequency of adverse effects. Although substantial gains in muscle mass and strength can be realized in older men with supraphysiological testosterone doses, these high doses are associated with high frequency of adverse effects. The best trade-off was achieved with a testosterone dose (125 mg) that was associated with high normal testosterone levels, low frequency of adverse events and significant gains in fat-free mass and muscle strength.

limo
03-20-2011, 01:34 PM
These studies are very useful and contain outstanding information. However sometimes I wish they would just dumb them down a little so that the average person can understand what they are saying without having to read it several times. Example if 100mg of steriod A is more effective when administered in oil instead of water...then I wish thats how they would say it......just sayin

goanywhere
03-21-2011, 03:15 PM
What about the older guys

Ronny thank you - I appreciate it very much. I am not quite there yet - but closer than I want to be.

And like Limo - I to have to read it several times. But it is very interesting - and very much appreciated.

goanywhere
03-21-2011, 03:15 PM
These studies are very useful and contain outstanding information. However sometimes I wish they would just dumb them down a little so that the average person can understand what they are saying without having to read it several times. Example if 100mg of steriod A is more effective when administered in oil instead of water...then I wish thats how they would say it......just sayin

I thought I was the only one [ that had to read it over and over ]

DiscoDino247
03-22-2011, 09:38 PM
thanks for the info, very informative. I never would have thought glute injections were better than site (delt) injections. See you learn something new everyday!

RonnyT
04-28-2011, 02:33 PM
We all learn every day, there are many studies done now, mostly thanks to us, we didn't believe the initial scaremongering from the whitecoats and used for athletic - performance - cosmetic reasons for anti-aging etc, now the scientist have reasons and funds to perform studies and surveys. Those find their way to the world wide web and we all benefit. Now with an aging population that wants to stay and look young and wants to maintain their libido etc scientists have more reasons ( MENT by example and HRT) just like pharmaceutical companies (see the moneymaker Viagra for pfizer) and what do you think happens if they would find a "cure" for obesitas??


thanks for the info, very informative. I never would have thought glute injections were better than site (delt) injections. See you learn something new everyday!

ODB
04-28-2011, 02:41 PM
Hopefully with more reputable studies + forums such as JM we can educate more people and start a grassroots campaign to repeal the "Anabolic Steroids Control Act of 1990" + the amendment - "Anabolic Steroid Control Act of 2004". Effective January 20, 2005.

One can only hope :)

limo
04-29-2011, 04:03 AM
lets just all get together and celebrate the fact that we still have access to legit steriods at an affordable price......with that said i'm retiring to my room for a quick injection

SuissePharma
12-02-2011, 10:16 PM
If you watch the disappearence rate of sesame you can think how it will influence quickly diappearing short estrifications like by example propionate.

For some unknown reason I canĀ“t klick on the icons, can you give me the direct links?

Thanks.

RonnyT
12-03-2011, 05:05 PM
The website has been hacked. When the IT team brought it back online the pics where gone. Yesterday i tried to post new pics but didn't succeed, You can find the pics in the links posted here in this thread from all studies. Later i'll ,make an article about it on the blog.

RonnyT
03-04-2012, 09:07 AM
still not finished yet but I made a start here.. http://juicedmuscle.com/jmblog/content/effect-steroid-esters

BeauBody38
01-10-2015, 03:59 AM
Depot steroids Drug Active half-life
Deca-durabolin (Nandrolone decanate) 14 days
Equipoise 14 days
Finaject (trenbolone acetate) 3 days
Primobolan (methenolone enanthate) 10.5 days
Sustanon or Omnadren 15 to 18 days
Testosterone Cypionate 12 days
Testosterone Enanthate 10.5 days
Testosterone Propionate 4.5 days
Testosterone Suspension 1 day
Winstrol (stanozolol) 1 day

Steroid esters Drug Active half-life
Formate 1.5 days
Acetate 3 days
Propionate 2 days
Phenylpropionate 4.5 days
Butyrate 6 days
Valerate 7.5 days
Hexanoate 9 days
Caproate 9 days
Isocaproate 9 days
Heptanoate 10.5 days
Enanthate 10.5 days
Octanoate 12 days
Cypionate 12 days
Nonanoate 13.5 days
Decanoate 15 days
Undecanoate 16.5 days