A baffling trend came to my attention recently. Surely this can't be right, I thought- people taking high-dose niacin to pass a drug test? Really? I lack the proper words... so I'll just cut to the chase.
The Claim:
Taking high doses of niacin aids in detox and/or passing a drug screen.
Let's deconstruct.
First- what is "detox" anyway?
Generally? Beats the hell out of me. Being a real pharmacologist, I don't buy into this whole "toxins" and "detox" nonsense. But in the context of the claim, the intent is to beat a drug test by somehow reducing the concentration of drug (or drug metabolite) in the bloodstream or urine below the detection limits of the test. I say "bloodstream or urine" because what comes out in the urine is a direct result of stuff getting metabolized from your bloodstream.
Ok, so what is niacin, and what does it do?
Niacin, also known as nicotinic acid, is typically used as an aid in treatment of hypercholesterolemia (high cholesterol). It does this by inhibiting mobilization of free fatty acids to the bloodstream (thereby preventing the liver from turning those free fatty acids into triglycerides, which affect synthesis of the "bad" LDL cholesterol), but it also has some other effects. The most notable side effect of niacin treatment for hypercholesterolemia is flushing, which can be severe enough to prevent people from using niacin regularly enough to keep their cholesterol under control.
Flushing in this context refers to a skin reaction. Niacin use can trigger skin redness, heat, itching, and tingling. The flush may be limited to the face and upper body with a lower dose, though a higher dose might cause more widespread flushing. The mechanism largely considered to be behind this is a vasodilation, or dilation of the small blood vessels near the surface of the skin.
So I guess this is where the "flush" the drug out of your system idea comes from? It sounds like a stretch, in my mind, but that's all I can gather.
How do drugs wind up at detectable concentrations in the bloodstream to begin with?
Pharmacokinetics! I thought it was just one class I had to take some years ago- but no, it just keeps on showing up in real world situations. I wrote a couple posts that might serve as useful background here (Part 1) and here (Part 2).
When you take any drug, it distributes to your body via the bloodstream. Your liver breaks it down, and then you have metabolites circulating until you eliminate them in the urine or feces or sweat or other excretion. The body takes a bit of time to do all this breaking down and elimination, so for a certain time period after drug use, your drug exposure can be determined using a test of urine or blood. This is directly related to the elimination half-life of the drug, and of its metabolites. (And these vary by drug.) You come up with a sensitive enough test, and you can detect vanishingly small quantities of drug or metabolite. This means you end up with a longer period of drug exposure detection.
For drugs that store in the fat, like THC, elimination requires the drug coming out of storage in fat tissue before the liver metabolism step. The slowest step by far is coaxing that fat-soluble drug out of the fat tissue, where it's perfectly happy to just hang out. This is achieved by gradient equilibration. That means that if there is more THC in the fat tissue than the bloodstream, it will follow the concentration gradient to the lower-concentration side, the bloodstream.
Then how does one go about "flushing" the drug molecules from the body?
Simply put? (Using THC as a common example...)
You can't convince all the THC that may be stored up in fat cells to come hang out in the bloodstream for your convenience. There are next to no feasible ways to actively modify the concentration of a drug or its metabolites in your bloodstream, at least in the downward direction. Vasodilation and the increased blood flow that comes with it does not change the concentration of a drug in your bloodstream, does not change the concentration gradient, and does not coax anything out of your tissues. (And we're talking about molecules here. Most especially in the case of fat-soluble molecules, they don't need vasodilation- they get into the tiny blood vessels just fine on their own.)
Bottom line. What will niacin do to decrease or mask the concentrations of drug in the bloodstream?
While niacin is known for causing "flushing" of the skin (and by that I mean redness), I want it to be absolutely clear that it does not "flush" anything else. That means it does not flush the drug molecules from your body. Not only does this regimen fail to have the desired effect, at the doses that I've heard or in attempting this detox myth, this can also fall into the "more harm than good" category. Folks, the only sure way to pass a drug test is to abstain from the drug for a long enough time to eliminate all of it. Period.
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delayed h/t goes out to WhizBang! for the inspiration.