ergo-log.com

Definition: "An ergogenic aid is any substance or phenomenon that enhances performance "

about us

/

contact

/

24.03.2019


MK-4541: a SARM that makes muscles stronger and kills cancer cells

In the second decade of this century, the research department of pharma giant Merck investigated a SARM that switches off the androgen receptor in the prostate, kills prostate cancer cells, but increases muscle mass and strength. As promising as this may sound, we, the Ergo-Log whines, are wondering whether MK-4541 will ever be released.

MK-4541
In 2014, Merck researchers published an article in the Journal of Steroid Biochemistry & Molecular Biology in which they described test tube and animal studies with the a new SARM. [J Steroid Biochem Mol Biol. 2014 Sep;143:29-39.]

That SARM was called MK-4541. It is, just like finasteride and dutasteride, a 4-azosteroid. The researchers found MK-4541 when they screened three thousand potentially interesting substances.


MK-4541: a SARM that makes muscles stronger and kills cancer cells



Merck is searching for new drugs against androgen-sensitive prostate cancer. Nowadays, prostate cancer patients' treatment still relies heavily on antiandrogens such as bicalutamide, which eliminate all androgen hormones. Bicalutamide attaches itself to the androgen receptor so that other hormones can no longer do so, without cells subsequently behaving differently. Bicalutamide therefore switches off the androgen receptor.

The researchers are working on a new generation of antiandrogens that deactivate the androgen receptor in prostate cancer cells, but take over the role of hormones such as testosterone and DHT in other cell types. MK-4541 may be such a new antiandrogen. Merck discovered that, in test tubes, MK-4541 activated the caspase-3 suicide enzyme in prostate cancer cells.

Click on the figure below for a larger version.


MK-4541: a SARM that makes muscles stronger and kills cancer cells


MK-4541: a SARM that makes muscles stronger and kills cancer cells



In animal studies, in which rats received MK-4541, the SARM reduced the prostate and seminal vesicles to a greater extent than bicalutamide. Bicalutamide reduced muscle mass, MK-454 left it intact.

Second study
In 2016, Merck, again in the Journal of Steroid Biochemistry & Molecular Biology, published more data. For example, the researchers explained how they injected test animals with prostate cancer cells, and saw that both MK-4541 and bicalutamide were able to inhibit tumor growth.

In that study, the researchers gave MK-4541 to castrated rats, and saw that the SARM increased lean body mass [in this case: both muscle mass and bone mass] and muscle strength. If the mice had been 80 kilo people, they would have swallowed 400 milligrams [no sir, it's not a typo] of MK-4541 daily.


MK-4541: a SARM that makes muscles stronger and kills cancer cells



This dose did reduce testosterone levels in intact mice. The effect you see below is not statistically significant, but the trend is unmistakable. Higher doses of MK-4541 did induce a statistically significant reduction in testosterone levels.


MK-4541: a SARM that makes muscles stronger and kills cancer cells



Conclusion
"MK-4541 is a SARM that exhibits unique pharmacological activity, including the inhibition of prostate tumors," the researchers summarize their findings. "MK-4541 inhibited androgen dependent prostate tumor growth as effectively as bicalutamide."

"Importantly, MK-4541 also increased lean body mass and skeletal muscle function, as well as increased general activity levels during the wake cycle in castrated adult mice, while maintaining normal activity and body composition in intact rodents. Thus, MK-4541 is an exciting and promising candidate to be tested clinically to treat prostate cancer. "

We wonder whether Merck's research department has continued the MK-4541 project. The doses required for biological effects are very, very high...

Source:
J Steroid Biochem Mol Biol. 2016 Oct;163:88-97.

More:
S42, the Japanese fat loss SARM 05.02.2019
The anabolic effect of GSK20881078: human study 31.10.2018
GSK2881078 - SARM star rising 30.01.2018

Archives:
SARMs


How safe is S23? LG121071, ACP-105 and LGD-3303: three SARMs you probably haven't heard of Bolandiol: the cheapest SARM was marketed as a prohormone

How safe is S23?
A 2009 animal study, in which researchers at GTx tried S23 out on rats, suggests that S23 is a little more risky than other SARMS.

LG121071, ACP-105 and LGD-3303: three SARMs you probably haven't heard of
SARMs such as S4, MK-2866, LGD-4033, YK11 and RAD140 are familiar names in the chemical sports world. These three are not. Not yet.

Bolandiol: the cheapest SARM was marketed as a prohormone
Those familiar with ergogenic aids tend to think that SARMs are complex compounds, of which the side effects are not known. This picture is not quite accurate.