This is something I skimmed over in my initial article on Cardarine.
I wanted write a dedicated article on this topic as I believe the human equivalent Cardarine dose that caused cancer growth is often calculated incorrectly.
Many people think the dosage is some exorbitant amount and they use that to justify their use thinking the human equivalent dosage that caused cancer in rats was thousands of milligrams, when in reality, it really wasn't.
With that being said, I don't necessarily think that it's inherently carcinogenic at all.
I just want to clarify the data for you in an easy to understand way, show how to calculate the human equivalent dose, and then let you make your own conclusions about it from there.
How The Cardarine Cancer Data Is Flawed
At the 48th Annual Meeting of the Society of Toxicology in 2009 (2 years after Cardarine's abandonment), data was presented showing that Cardarine caused cancer to develop rapidly in several organs in animal testing [R].
As I mentioned in my first Cardarine article in 2016, the first thing to note is the fact that the aforementioned study involved in administering Cardarine to Han Wistar rats for almost two years straight.
The Life Expectancy Of Han Wistar Rats
Without being administered any chemicals at all, the median life expectancy of Han Wistar rats is between 30 to 33 months for females and 33 to 36 months for males.
The reason for their short life expectancy is the number of adenocarcinomas that they develop [R].
Before we even look at the animal models, you already know that the rats are not expected to live more than three years, irrespective of what they're administered, because of their very high probability of developing cancer.
For obvious reasons, I feel like that in itself makes the data pretty unreliable, but let's continue.
The Dosages Used In The Cardarine Preclinical Rodent Model
The dosages administered to rats over the two-year study varied widely, but the lowest dosage showing cancer cell proliferation in the rodent model was 3 mg/kg/day in Han Wistar rats for a period of 104 weeks [R].
The Average Weight Of Han Wistar Rats
The average weight of a Han Wistar rat is 509 grams, or 0.509 kg [R].
How To Calculate A Human Equivalent Dose
The following equation is used to calculate roughly what that dosage would equate to in humans:
HED (mg / kg = Animal NOAEL mg/kg) × (Weightanimal [kg]/Weighthuman [kg])(1–0.67) [R].
Human Equivalent Dose Of Cardarine That Led To Cancer Cell Proliferation
I'll use an 80 kg man as an example to calculate this dosage.
This will give you a fairly average reference point of what the human equivalent dose would be in this context.
Assuming we have an 80 kg man that we are using for this calculation, we get the following result:
Human Equivalent Dose = (3) × (0.509/80)(1–0.67)
Human Equivalent Dose = (3) x (0.0063625)(0.33)
Human Equivalent Dose = 3 x 0.18845044723
The human equivalent dose, once you break down the calculation comes out to 0.5653513417 mg/kg.
Once you multiply that and factor in the bodyweight of an 80 kg human male, you get 45.2281073363 mg.
Frankly, that is not far off from the minimum human equivalent dosage to yield accelerated cancer development in the aforementioned rodent model.
Does that mean people who are using Cardarine are going to develop cancer?
Not necessarily, because frankly, I feel like using a rat as your reference point that is very likely to get cancer anyway is a pretty poor proxy for what will happen in humans.
These rats were administered high doses of Cardarine for over 2/3 of their lifespan.
They are also already extremely prone to cancer without even being administered anything.
Has Any Human Developed Cancer Directly As A Result Of Cardarine Use?
Recreationally, the standard dosage of Cardarine used is between 10 to 20 mg per day.
Even those who use Cardarine recreationally at 20 mg per day typically don't exceed a couple months of use at a time, and they certainly don't use it for 2/3 of their lifespan without breaks.
Too much of anything is going to be bad.
Stand in front of your microwave or outside in the sun for 2/3 of your life and see what happens (don't actually do that).
You can see what I'm getting at though.
Chronic exposure to something potentially carcinogenic will certainly have deleterious outcomes.
Has any human developed cancer from Cardarine?
Not that I'm aware of.
But how could you quantify that exactly?
It's tough to say because cancer could be attributed to a million other things in somebody's lifestyle and Cardarine could go completely overlooked.
Anecdotally, Cardarine has been shown to be generally well-tolerated and there are studies that show it has anti-cancer properties as well [R].
As of now, there is zero evidence to support that Cardarine use at the dosages and duration of exposure used in human trials will cause cancer.
However, it is certainly still possible.
So… Does Cardarine Cause Cancer?
Your own risk profile at the end of the day is up to you.
The clinical studies conducted on humans using Cardarine for up to 3 months at 10 mg per day did not report any cancer.
Does that mean that any of those participants didn't have some cancer cell proliferation that led to cancer down the line?
I have no idea.
Frankly, I'm guessing there are at least 5-10 things in your house that are a higher cancer risk than short-term acute use of Cardarine, but that is just my guess at the end of the day.
I have yet to see any evidence of its use in humans accelerating cancer cell growth.
For lipid modulation, I have used it at 10 mg per day.
Would I go higher than that?
No, I would not to be honest.
Even at 10 mg per day with very short-term use the cancer data is still worrisome.
This is why I would reserve it exclusively for addressing a poor lipid profile that is an immediate health concern and cannot be resolved via other lower risk methods of intervention.