Active Half-Life of Steroids

[goanywhere]

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?

[iamready]

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?

[RonnyT]

solvents co-solvents and oils..

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.

[RonnyT]

volume concentration viscosity chemical art

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.

[SAFELIFE1]

Yep and you can download the whole study here http://www.eje-online.org/cgi/conten...ract/140/5/414 the pdf on the right side of the page.

Thanks RT. Good info.

[goanywhere]

Bound or Free?

Are the half lifes measured here for bound T? Free T? Or total? In my simple understanding - bound is useless. Free is what counts.

[goanywhere]

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.

[Bo Deen]

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]

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.

[iamready]

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

[RonnyT]

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.

[RonnyT]

Yep and you can download the whole study here http://www.eje-online.org/cgi/conten...ract/140/5/414 the pdf on the right side of the page.

[dino]

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

[goanywhere]

I find it interesting and always want to learn more. I don't know about anyone else.

[RonnyT]

an other aspect

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..