transdermal & trenbolone


New member
I was able, with the help of ZEN42 better understand the relationship between transdermals and tren....
The primary concern for a transdermal to be effective is the molecular weight of a molecule. Trenbolone's molecular weight is 270, Trenbolone Acetate is 312. To compare with other molecules used in transdermal applications... progesterone is 314 (birth control) and finastride is 373 (propecia).

Here's one study...

J Pharm Pharmacol 2000 Apr;52(4):369-75

Skin permeation of testosterone and its ester derivatives in rats.

Kim MK, Lee CH, Kim DD.
College of Pharmacy, Pusan National University, South Korea.

To establish the optimum conditions for improving the transdermal delivery of testosterone, we studied the relationship between the lipophilicity of testosterone ester derivatives and the rat skin permeation rate of testosterone. We performed a rat skin permeation study of testosterone and its commercially available ester derivatives, testosterone hemisuccinate, testosterone propionate and testosterone-17beta-cypionate, using an ethanol/water co-solvent system. The aqueous solubility and rat skin permeation rate of each drug, saturated in various compositions of an ethanol/water system, was determined at 37 degrees C. The aqueous solubility of testosterone and its ester derivatives increased exponentially as the volume fraction of ethanol increased up to 100% (v/v). The stability of testosterone propionate in both the skin homogenate and the extract was investigated to observe the enzymatic degradation during the skin permeation process. Testosterone propionate was found to b
e stable in the isotonic buffer solution and in the epidermis-side extract for 10h at 37 degrees C. However, in the skin homogenate and the dermis-side extract testosterone propionate rapidly degraded producing testosterone, implying that testosterone propionate rapidly degraded to testosterone during the skin permeation process. The steady-state permeation rates of testosterone in the ethanol/water systems increased exponentially as the volume fraction of ethanol increased, reaching the maximum value (2.69+/-0.69 microg cm(-2)h(-1)) at 70% (v/v) ethanol in water, and then decreasing with further increases in the ethanol volume fraction. However, in the skin permeation study with testosterone esters saturated in 70% (v/v) ethanol in water system, testosterone esters were hardly detected in the receptor solution, probably due to the rapid degradation to testosterone during the skin permeation process. Moreover, a parabolic relationship was observed between the permeation rate
of testosterone and the log P values of ester derivatives. Maximum flux was achieved at a log P value of around 3 which corresponded to that of testosterone (log P = 3.4). The results showed that the skin permeation rate of testosterone and its ester derivatives was maximized when these compounds were saturated in a 70% ethanolic solution. It was also found that a log P value of around 3 is suitable for the skin permeation of testosterone related compounds.

PMID: 10813545

What this study shows several things:

1. That 70% alcohol works as a transdermal.
2. The esterfied steroids work as transdermals. (Test Cyp has molecular weight of 412).
3. The ester appears to have been stripped by the skin (more later).
4. Note the reference of log(p). Log(p) is a critical element. (TA's log(p) is about 3.4)

Regarding the ester being stripped (non-technical term). Hormones are broken down in the body by enzymes. This done by organs. 17AA oral steroids are broken down by the cytocrome p450 enzyme (if I recall correctly) in the kidneys. This is why they are so hard on the kidneys. Trenbolone is known to be broken down by the kidneys and the liver. It may also be broken down by other organs also. To the best of my knowledge, they don't know which enzyme is responsible. There is no evidence that TA is hard on the renal system. So it's not suprising to hear that the ester is broken down by the skin. Skin is an organ!

So you know...once it enters the body, the body strips the ester in Trenbolone Acetate leaving Trenbolone. This is then metabolized into many different metabolites, only three of any real quantity. One of those metabolites is believed to be the main anabolic component of TA. The body then removes these metabolites relatively quickly out of the body. I believe almost all evidence of TA is gone within three weeks.

Here is a critical line from one medical abstract that shows a gel's bioavailability of 61% (I've seen higher).

Maturitas 1999 Jun 21;32(2):103-13
Absorption and bioavailability of oestradiol from a gel, a patch and a tablet.

...The bioavailability of oestradiol from the gel was 61% as compared with the tablet...

So anybody who says only 10% bioavailability doesn't know what they are talking about.


i hope this has helped some of you better understand the way tren can work with a transdermal or any compound with a molecular weight viable for a transdermal...
Luv super
good read SG , ps next time draw pictures for us powerlifters , this doctor talk is confusing :p
Just an added comment...

Molecular weight is a critical factor, but there are several other variables involved in transdermals. For example, I had mentioned log(p) above without any detail. This is a number that represents the lipophilic/hydrophilic properties of the molecule. Ideally a transdermal solution should be contructed to best match the log(p) of the applied molecule.

What to remember is that virtually all hormones (steroids), by their nature are candidates for a transdermal application. Trenbolone, for various reasons, is a very good choice.

One other comment, I get uncomfortable whenever the discussion of "Conversion Rates" comes up in regards to Trenbolone. This is because of how well the body metabolizes the chemical. The method of application determines the length of time that useful blood levels of TA remain in the system.

To take two opposite examples, sub-lingual application of TA is readily absorbed into the body (high "conversion rate"), but the blood levels spike quickly and then take a major drop. Those who've had good success with subliguals have had to spread the dosages throughout the day.

Transdermal application does a very good job of spreading out the dosage as it takes up to 10 hours for 90% of what will be delivered to be delivered. (If that sentance makes sense.) So two applications a day make for a very steady blood levels of TA.

Because of blood level effects (some that help and some that hurt) of application the measure I use, which is an unscientific one, for "conversion rate" is to measure reported results against similar results of injected TA. Using that definition, I've seen some transdermal formulations produce results equivalent to a injectable at 70% of the transdermal dosage. The challenge then is to create a formulation that isn't too harsh on the skin but still produces good results. It is very feasable to deliver as much TA to the system as via an injection (by applying more).

awesome Zen....... THANK YOU SO MUCH for chiming in here and for all your help in better understanding tren and transdermal delivery..

Welcome to the board and i only hope you stay around and post as you are the research guru and have such a scientific brain!!!

thanks again

i second SUPERGIRLS welcome , we need a few more gurus , especially on this subject , there is so much conflicting opinion on the subject but i do know this if test cream works and that has been proven in the medical community then tren should work if we can find the right carrier , everybody spouts off INJECT IT but some people allready have scar tissue buildup or are injecting so much other stuff allready transdermal gives them another option , damn that was a long welcome:D
Thanks all...

This isn't an easy subject to understand and research. I got interested in 2001 in both Fina and Transdermal. I got hooked when I found that a lot of the information floating around wasn't accurate. I started digging into the scientific literature and many others added information they found. These boards work best when everybody is throwing in information they've found and bouncing information off of each other.

As for "Inject IT" crowd...

I'm an agnostic on the subject. I don't care if somebody wants to inject, spray, rub, snort, suck or insert. As long as they understand what they are doing I'm fine with it. I just hope others are equally respectful. I find the transdermal (particularly sprays) interesting and I've enjoyed doing the research.

Dadawg, there are a lot of valid reasons for somebody wanting to try a transdermal solution you listed a couple of them. You'll be glad to know that a good transdermal spray can be cost comparable to buying a kit. Of course most people will inject and that's a perfectly good choice, but its nice to know there are options.

Having said that, some of the ways that transdermal is attempted really is a waste (and a mess) and I understand why some have a bad opinion on transdermals in general.

Dominique said:
after consulting my medical dictionary, I have to agree with the rest, great post....:)

LMAO.. i hear ya.. these science abstracts can get tricky :) but unfortunetly they are the only way to really get to the bottom of uses and the way gear works etc...

welcome aboard btw :)
My first post here. I hope this isn't threadjacking, but it seems relevant, and there are already umpteen fina threads.

So, when you say transdermal fina with PLO gel, does anyone use this supercomplicated method to make the gel described in:

except with female sized amounts?

Or do people just tend to crush the things up and disolve in alcohol and add PLO gel?


Hey Wyst :blue: good to have you here!!!

basskiller has a fantastic page dedicated to transdermal and fina!!!

I personally... take a pellet, crush it, dissolve it in alcohol and mix into a gel using plo.. then apply.. that works for me PERSONALLY... i am probably losing some of the potency that way i have come to realize, but since it is so damn strong, the little bit i am getting is more than enough to get me results without the sides!!!

you try it yet???
Nope, not yet! I'm still in research mode.

I saw that basskiller page--looks very complicated. I'd say if you're a guy and you were worried about squeezing every last drop of goodness out of the fina, that might be worth it.

Unless there's some other reason for making it that way (detox or some such), that's cool...I was kind of thinking that it might not be such a big deal to do it that way.


so then the skin acts as a de-esterification medium? wow, first i have heard of that to be honest, i realize the skin is an organ and can do some miraculous things but im not sure i believe its ability to strip an ester from a compound....shooting an email to one of the biochem prof's at the university....
I'm not sure I'm comfortable with saying that skin is a "de-esterification medium". A little too much of a blanket statement for my taste. While it appears to do so in some cases, it can't be said (for certain) that it would in all cases.

There are enzymes in skin and as a transdermally applied molecule moves through the skin it would be subject to the enzymes. The study that was referenced above does show that transdermally applied Test Prop was "de-esterfied" (at least partially) as it moved through the skin.

I don't believe it is known what enzyme(s) break down Trenbolone Acetate to the metabolites that ultimately get flushed from the body. If those enzymes are in the skin, I would expect at least some of the trenbolone to be broken down there. If transdermally applied TA is not broken down by enzymes in the skin, then it most likely would then be broken down mostly by the kidney and liver.

From what I've seen, there has been precious little written about enzymatic actions on transdermally applied chemicals (not a lot of research). If you get any references from your professor I would love to hear about them.
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