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7 ways thermogenics can boost your metabolism and burn fat

Last updated: October 25, 2022

Looking to boost your body’s metabolism? A thermogenic supplement could be the ticket. These supplements are designed to work by upregulating your baseline metabolic rate, and by accelerating your fat oxidation.

They’re a great compliment to a weight loss routine, since they can help increase your overall caloric expenditure and increase your weight loss. In addition to their use by dieters, thermogenics are also commonly used by bodybuilders and athletes to melt off body fat while preserving lean body mass.

Regardless of your use case, there’s a plethora of benefits to taking a thermogenic supplement. Our research team compiled a detailed run-down on the most important ways these supplements can help you increase your energy expenditure and decrease your body fat.

Thermogenics benefits

1. Thermogenics increase your body’s rate of caloric expenditure

If you eat less and burn more, you’ll lose weight. That’s axiomatic.

This is where thermogenic supplements come in. The right thermogenic supplement can increase your body’s “set point,” making it burn more calories at its baseline resting state.

2. Thermogenics can change your body’s energetic expenditure set-point

The most effective thermogenics, like caffeine and green tea extract, have strong and significant effects on your baseline metabolic rate, according to nutritional research using careful measurements of real-time metabolism (1,2).

The result? More calories burned in a day, without changes to your exercise routine.

3. Thermogenics can specifically target fat cells

An especially attractive aspect of the most effective thermogenics, like green tea, green coffee bean, and cayenne pepper extracts, is that they preferentially target fat cells for oxidation (3).

This means that you get an even bigger weight loss benefit, since a greater proportion of your energy is coming from stored fat.

4. Good thermogenic supplements have ingredients that work in a synergistic fashion

A classic example of this kind of synergy is between green tea extract and caffeine.

The EGCGs in green tea extract interact with caffeine to produce greater rates of fat oxidation than you’d expect from either ingredient alone (4).

That means you get an additional bonus fat-burning effect when you combine both ingredients in one supplement.

5. A thermogenic with capsaicin can upregulate oxidation in fat cells

Capsaicin (a compound found in chili peppers) activates specific energy-burning pathways inside fat cells (5), without a stimulant effect. That’s why you’ll find it in many high-quality thermogenics, even those that are stimulant-free.  

6. Several herbal extracts can generate thermogenic effects

One review study from Harvard Medical School cites the thermogenic potential of a wide range of herbal extracts and micronutrients including acetyl-L-carnitine, garcinia cambogia, B vitamins, and conjugated linoleic acid (6).

These are among the most effective ingredients to look out for in a thermogenic supplement, since they have the strongest support among the wide range of potential ingredients you might find in a thermogenic.

7. Green coffee beans boost metabolism and fat oxidation

Green coffee bean extract is a newer supplement, but evidence is accumulating that it can increase both your metabolic rate and your fat oxidation rate (7,8,9).

Like green tea extract, it appears to exert an effect above and beyond what you’d expect based merely on its caffeine content alone. 

Thermogenics side effects

Thermogenic supplements are one category of supplement that are difficult to get right. It’s easy to overshoot and overstimulate the body, which can lead some problematic side effects:

Caffeine in a thermogenic can cause jitters, anxiety, and sleep disturbances. Some medical case reports even cite cases of cardiac arrhythmias due to excessive caffeine consumption (10).

In moderation, caffeine is an effective thermogenic, but too high a dose can bring on these side effects. 

Other stimulants can cause similar adverse effects to caffeine. Another famous example is the supplement ephedra, which used to be widespread among thermogenic supplements.

After studies found that it was associated with serious side effects (11), supplements containing ephedra were pulled from the market.

Synephrine and bitter orange extract may cause cardiac side effects. A report from the Canadian Medical Association cited several cases where suspected cardiac side effects occurred in patients who were taking supplements that contained synephrine (12).

While these numbers aren’t nearly as severe as the numbers that poured in regarding ephedra, we didn’t include synephrine-based supplements in our rankings for this reason.

Thermogenics dosage

The effective dose of a thermogenic is going to depend on the active ingredients. For the highly effective ingredients we discussed earlier, the most-studied doses are as follows.

Caffeine: maximal effects come from dosages of 200 mg per day or below. As noted above, caffeine in too high of a dose can cause side effects. Fortunately, you can get solid results from moderate dosages (13).

Green tea extract is most often studied at doses of 400-800 mg per day. This dosage maximizes the benefits you get from the EGCG in green tea (14).

Capsaicin is probably effective in the 30-150 mg per day range. Since it’s a newer supplement capsaicin (cayenne pepper extract) has a less well-established ideal dosage range, but it’s been studied with success in this dosage range (15).

Thermogenics benefits FAQ

Q: What does thermogenic mean? 

A: The literal translation of thermogenic means “heat generation”–thermo- as in thermal, and –genic as in generate. A thermogenic supplement is one that increases your baseline metabolic rate, and hence increases your body’s caloric expenditure.

Often, the way this happens is by increased fat oxidation. When thermogenesis happens through this route, it’s doubly beneficial for weight loss, because you are burning more calories, and those calories are coming directly from fat stored in fat cells. 

Q: What do thermogenic pills do? 

A: At a basic level, thermogenic pills increase your body’s caloric expenditure by increasing your baseline metabolic rate and increasing your fat oxidation rate.

The absolute increase in energy expenditure is moderate, so many people combine thermogenic pills with more traditional weight loss strategies like diet and exercise to increase their rate of weight loss.

Q: What are some thermogenic foods? 

A: The best “food” for thermogenic effects is probably coffee and tea.

Beyond these two, foods that are high in protein have a pretty powerful thermogenic effect, like eggs, chicken, and salmon.

That’s because eating protein causes an increase in energy expenditure in the time after the meal, at least compared to an equivalent amount of carbohydrates or fat.

Q: Are there thermogenic probiotics?

A: Some probiotic bacteria do exert a thermogenic effect by breaking down energy for their own use.

The energy production of probiotic bacteria does not always overlap with calories that your body would have consumed, though; for example, some probiotic bacteria can digest forms of fiber that your body would not be able to use for energy (16).

Though there is a lot of promise for future research in this area, right now we don’t know enough to definitively say that any particular kind of bacteria can be considered a thermogenic.

Q: Do fat burning supplements work?

A: Yes, if you choose the right thermogenic, there is a demonstrated increase in fat oxidation as a result of the thermogenic ingredients in the supplement (17).

However, whether this translates into actual weight loss will also depend on your overall lifestyle.

If all you do is start taking a thermogenic supplement, and don’t change your dietary or exercise habits, you might lose a few pounds per month.

If you take a thermogenic supplement, and start a weight loss program that involves exercise and a better quality diet, you can see much more substantial effects. 

Related: Our best thermogenics picks


For people who are serious about shedding excess body fat, a thermogenic could be a huge help. These supplements are designed to boost your metabolism and increase your rate of fat oxidation, helping you melt off fat at a faster rate.

If you’re looking for a good thermogenic supplement, make sure it contains proven fat burners like green tea extract, capsaicin, CLA, and green coffee bean extract. Supplements including these compounds will give you the best chance of hitting your body composition goals.


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