How Long Do Fat Burners Stay in Your System?

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Fat burners can be a great aid to your weight loss routine. They enhance metabolism, increase energy expenditure and boost fat oxidation during exercising. Many fat burners can also be taken on rest days – their effects will help you even when you do not work out. Yet, you do not want to overdose them. Like with anything, taking too many fat burning supplements may have severe consequences. To prevent that from happening, you need to understand how long fat burners stay in your system. This exactly what we will focus on in this article. Thus, if you desire an answer, we encourage you to read on.

How long do fat burners stay in your system – why you should know it?

Fat burners consist of different ingredients, each of them aiming at reducing the amount of fat in your body. Yet, many of these substances are natural: caffeine, taurine or EGCG can be foods and drinks such as red meat, tea or coffee. This means that by using these supplements, you actually combine them with the natural fat-reducing elements that you consume every day. It makes it much more possible for you to simply take too much.

Knowing how long do the fat burners stay in your system is crucial. Most active substances in them affect your metabolism in the liver, thus overdosing may cause its failure. By knowing when your fat burners leave your system, you are able to estimate when you should take the next portion, without risking taking too much. It is important since, unlike the pre-workouts, fat burners should be taken also on rest days, and this increases the possibility of exceeding the suggested intake.

So, how long do fat burners stay in your system?

Unfortunately, there is no simple answer to this question. Depending on the sources and physicians that you will ask, you will hear that the time fat burners remain in your system varies. The factors that can affect this period are:

  • types of active substances,
  • Your own metabolism,
  • dosage.

Yet, you should also remember that fat burners are usually designed to be taken daily. Yet, they can remain in your system for several hours, and it might even take days to remove some of the ingredients. Thus, similarly to what we did when answering the question of taking fat burners without working out, we need to focus on particular ingredients.

How long does each fat burner ingredient stay in your system?

Before starting our analysis of each of the most popular ingredients, we need to underline the measuring method that we will use. Instead of presenting you with an exact time, we will focus on the product’s half-life – the amount of time required to reduce the concentration of a particular substance by half. We should also, mention that these are the average values, which might vary depending on dosage or your own metabolism.


Caffeine half-life varies depending on the sources, most of which propose values around 5 hours. Knowing this is quite crucial, since apart from fat burners, there are many other products that we consume every day that consist caffeine. Coffee, energy drinks, tea or even pre-workouts are all on this list, so you should pay close attention when mixing them.


Another popular ingredient of energy drinks and fat burners is taurine. Its half-life is much shorter than this of caffeine, and is estimated between 45 minutes to 1 hour 20 minutes. Since it is also widely used in pre-workouts, it might be wise to avoid taking them and taurine containing fat burners at the exact same time.


This metabolism-boosting substance is a trademark of green tea and its extracts, which are widely used in fat burners. The estimated half-life time for EGCG is about 6 hours, making it last in your system even longer than caffeine. Thus, you should be wary of drinking your favorite green tea while taking fat burners.


This amino acid is responsible from transporting fat from the cells to the bloodstream, thus accelerating the metabolism. It is widely used in numerous fat burners. The half-life for L-carnitine is about 1 hour, thus taking too much of it should not be a problem if you use your supplements daily.


Yohimbine is used in fat burners, since it can increase energy expenditure. While it is not that strong, it serves as an additional boost to other active ingredients. It is impossible to estimate Yohimbine’s half-life accurately, yet most sources calculate it as a range between 30 minutes and 2.5 hours.


DMHA or dimethylhexylamine is responsible for boosting energy levels and reducing appetite, making it a popular ingredient for both fat burners and pre-workouts. There has not been enough research on its half-life, though it is presumed to be similar to the one of DMAA which is 9–11 hours. Considering that this substance has one of the longest half-lives of all the fat burner ingredients and that it is widely used in other supplements, you should be extremely cautious when using two products with DMHA in it.

Considering how long fat burners stay in the system, can I take them infinitely?

While taking fat burners in proper time intervals will indeed not be harmful, you cannot simply rely on them throughout your whole weight-loss journey. Firstly, they are stimulants and your body will simply get used to them. Secondly, it is possible that your system counter them by reducing your metabolism naturally, and it will then be extremely easy for you to gain weight after you stop taking them. Thus, it is good to use them as an additional boost when you begin losing weight, but you should not make a habit of taking them for months.

The takeaway

There is no simple answer to the question of how long do fat burners stay in your system. It depends on the active substances used in your supplement. Some will be removed from your body in a matter of hours, with others you will need a day or two. It is crucial to pay attention to the ingredient lists of your fat burners, pre-workouts or testosterone boosters, since many substances are used in all three of them and combining them mindlessly might be an easy way to a liver failure.

Did you like this article? You can check out our other posts, such as: How to boost testosterone?


Institute of Medicine (US) Committee on Military Nutrition Research. Caffeine for the Sustainment of Mental Task Performance: Formulations for Military Operations. Washington (DC): National Academies Press (US); 2001. 2, Pharmacology of Caffeine. Available from:

Janle, E. M., Morré, D. M., Morré, D. J., Zhou, Q., & Zhu, Y. (2008). Pharmacokinetics of green tea catechins in extract and sustained-release preparations. Journal of dietary supplements, 5(3), 248–263.

How long do fat burners stay in your system?

The duration that fat burners remain in your system can vary depending on several factors, including the types of active substances, your own metabolism, and the dosage. While there is no simple answer, fat burners can typically stay in your system for several hours to a few days.

Why is it important to know how long fat burners stay in your system?

Knowing the duration of fat burners in your system is crucial to prevent overdosing and potential health risks. The active substances in fat burners can affect your metabolism and liver, so understanding when they leave your system helps you avoid taking excessive amounts.

Can fat burners be taken indefinitely?

While fat burners can be beneficial when used in proper time intervals, relying on them continuously throughout your weight loss journey is not recommended. Your body can become accustomed to the stimulant effects, and there is a possibility that your metabolism may naturally decrease after you stop taking them, potentially leading to weight gain.

What is the main takeaway regarding the duration of fat burners in the system?

The duration of fat burners in your system varies depending on the active substances used in the supplement. Some may be eliminated within a few hours, while others can take a day or two to be completely cleared. It is crucial to carefully examine the ingredient lists of fat burners, pre-workouts, or testosterone boosters to avoid combining substances mindlessly, as it can potentially lead to liver failure.

Man exercises on a rowing machine

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