Article updated: 2021 Mar 11 / Author Leslie Griver, Robert Henry

Does Niacin Clear Your System of THC

Niacin can help you pass a drug test as a component of the same-day solution.

However, if you need to remove marijuana from your system completely, Niacin will only interfere with this.

Niacin blocks the breakdown of body fat, and thus metabolites will not be released from fat and excreted into the urine. This helps to lower the concentration of THC in the urine below the detectable level.

But Niacin can cause severe damage to your health.

There were dozens of cases where people ended up in hospital after using Niacin to pass a drug test.

Below we will explain what Niacin does to THC and tell you about a safe and free alternative to Niacin.

What is Niacin, and how does it work

Niacin is a Vitamin B3, also known as nicotinic acid.

It has long been used to increase high-density lipoprotein (HDL) cholesterol – the “good” cholesterol that helps remove low-density lipoprotein (LDL), the “bad” cholesterol from your bloodstream.

Here’s how it works:

Hormone-sensitive lipase(one of the enzymes in our body) breaks down the adipose tissue and releases free fatty acids into the bloodstream.

Free fatty acids get into the liver and are modified to triglycerides and then to LDL (low-density lipoprotein)

Hormone-sensitive lipase is a critical enzyme involved in the hormonally regulated release of fatty acids.

Niacin blocks hormone-sensitive lipase, so the fat breakdown is stopped, and consequently, the amount of LDL is lowered.


What Niacin does do to THC?

THC is stored in body fat tissues. Our body slowly breaks the fat tissues, releases THC into the blood, and then excretes it with urine and feces.

If you want to understand the whole process, here’s the detailed guide on marijuana metabolism: The Ultimate Guide to Marijuana Metabolism

When we consume Niacin, it stops the fat breakdown, and less THC is released into the blood and excreted.

So consuming Niacin can only help if you need to lower the concentration of THC in the urine. After taking Niacin, our body will excrete less THC.

If you need to detox from marijuana, you need to break down all the fat tissues containing THC to release and excrete it. Niacin will interfere with this process.

Why do people think Niacin will help them to pass a drug test

Here are what people advise on Reddit and forums:

“Niacin is often used to increase metabolism and burn fat (and that fat is what stores THC for up to 30 days)”

“Niacin may help boost your metabolism but not nearly enough to make a difference.”

“I know it will boost the metabolic rate which will help make it easier for the THC to be burned out of the fat cells.”

“Niacin speeds up your metabolism and help you burn fat which THC attaches to fat cells so in a way i think it helps”

As you see, all that statements are false. There’s scientific evidence that niacin doesn’t improve metabolism and doesn’t help to burn fat in any way.

“Niacin isn’t for cleansing. Niacin is for adding yellow color and certain natural body-byproduct chemicals back into your urine to cover up massive over-hydration prior to a drug test.”

This statement is also false. It is based on the fact that your urine color becomes pale when you drink a lot of water.

If you need to pass a drug test, such a pale sample will be rejected as diluted. To restore natural urine color, you need to take Vitamin B to give your urine yellow color.

But the only vitamin B that will make your urine yellow is riboflavin, vitamin B2.

Niacin(vitamin B3) will not change your urine color.

How do people use Niacin to pass a drug test and why does this work

Here are several methods that are described on Reddit and forums. We’ll explain the real reason why these methods worked:

“So, after not smoking for one week I took an at home test and failed. I took 5 niacin pills, 2 at first, 2 after an hour and another after a half hour and passed. But I’ve also taken up to 11 Niacin pills over the course of a few days before my test, and I do drink a lot of water”.

In this situation, the method succeeded because the person was drinking a lot of water. Thus he flushed the marijuana metabolites from the bladder, and their concentration in urine was below the detectable level.

By taking Niacin, he blocked the release of THC from the fat into the blood and the urine.

So only the last five pills of Niacin provided this result. But taking that much Niacin in a short period of time was dangerous because Niacin has severe side effects.

We’ll tell you about safe alternatives later in this post.

We should mention that the person used tested himself at home, and nobody checked his urine for pH, creatinine levels, and specific gravity.

The lab technician will check these parameters and reject your sample if they are out of the normal range.

“I would take five of these 500mg tablets each day for 1 week, 2 when he woke up, and 1 every 2 hours after that until he reached his maximum daily dosage of 2500mg. Also made sure to drank lots of water, not too much, but definitely about double of my normal amount.”

“This is just from my personal experience but i passed taking 4 of the big ones a day for 3 days. But i also didnt smoke for a week or two before. I also ran a shit ton, drank alot of water, and turned bright red”

The situation is the same in both of these posts. Both these persons drank a lot of water, which caused urine dilution and temporarily lowered the concentration of marijuana metabolites below the detectable level.

Side Effects of Niacin

Niacin does have some severe side effects.

The most common is flushing: warmth, redness, itching, or tingling of the skin. This may feel uncomfortable, but it is not serious.

If you take nicotinic acid as a medication in doses of 1,000 or more mg/day, it can cause more severe side effects, including:

Safe alternative

As we already explained in this post, Niacin can only help if you need to pass a drug test fast.

If you want to understand how our body processes weed, you can read it in detail here: The Ultimate Guide to Marijuana Metabolism

But there’s a simple and safe alternative to that. You can just eat a chocolate bar. The chocolate bar contains a lot of carbohydrates.

Most of us eat carbohydrates daily(except those who are on Keto-diet).

Eating carbohydrates ( chocolate bars, rice, pasta, drink coca-cola, fruits) will raise your insulin levels.

Insulin stops the breakdown of fat and prevents the breakdown of triglycerides into fatty acids.

As you see – the effect is the same as with Niacin. And there are absolutely no side effects, and this method is safe for the health.

So all you need is to eat some carbs 1-2 hours before the test. Here we explained the method in detail:  THC Detox Guide. How To Get Weed Out Of Your System


How quickly can Niacin get weed out of my system?

Niacin cannot clean weed out of your system. Niacin can prevent releasing of weed metabolites from the fat cells into the bloodstream and the urine.

How long does weed stay in your system if you take Niacin?

The weed will stay in your system longer if you take Niacin. Niacin prevents THC release and excretion.

How does Niacin help your body flush weed out?

Niacin temporarily flushes weed out of the bladder by preventing new weed metabolites from getting into the urine.

Will Niacin be detected in your system?

No, Niacin is not detectable by urine drug tests.

How long until Niacin leaves my system?

After taking your last dose of Niacin, it should be out of your system within 110mins to 247mins (2hrs to 4hrs)

Niacin has a short half-life of 20 to 45 minutes. This is the time it takes for your body to reduce plasma drug levels by half. It takes approximately 5.5 x elimination half-life for a drug to be eliminated from your system.

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