What Are Thermogenics and How Effective Are They?

What Are Thermogenics and How Effective Are They?

What Are Thermogenics and How Effective Are They?

When it comes to weight loss, there are a lot of products out there that claim to be the secret ingredient you’ve been missing; the one magic element that will help you lose weight fast. It can be difficult to navigate your way through these claims and work out which products are actually worth investing in. If you’ve done some research into weight-loss strategies, you’ve likely stumbled across the term thermogenics. It’s a bit of a buzzword in the weight-loss space. So, what are thermogenics and how effective are they? We break it all down in this guide.

What Are Thermogenics?

It’s all in the name, really. The word ‘thermo’ means related to heat. Thermogenic refers to the ability to produce heat.

When the body burns calories, it generates more heat. Consider how our bodies react to an increase in activity; when we exercise, our bodies get warmer.

The faster our metabolism, the more calories we burn. Thermogenic supplements contain ingredients that increase our metabolism, so they essentially help us burn more calories.

Generally, the more calories you burn, the quicker you lose weight. You can see how thermogenics are connected to weight loss.

Some supplements contain just one thermogenic ingredient, while others will blend a few different ones together to increase weight loss potential.

Is Coffee a Thermogenic?

One of the most well-known, commonly-used thermogenic ingredients is caffeine.

Caffeine is a stimulant that can be found in more than 60 plants. Many of us consume it regularly through foods and beverages — your coffee, green tea or pre-workout all contain caffeine.

So, why is caffeine considered a thermogenic?

Caffeine increases adrenaline levels in the body. Adrenaline is the hormone responsible for promoting your fat cells to release fatty acids into the bloodstream so that your cells can snatch them up and use them for energy.

In other words, caffeine stimulates adrenaline, which increases the amount of energy in your cells. This in turn increases your metabolic output, so you burn more calories and therefore lose weight.

Caffeine is an appetite suppressant, so it also helps to promote weight loss by causing you to eat less.

Consuming just a milligram of caffeine will help you burn an extra 0.1 calories in the 24 hours following ingestion. So, a 150mg dose of caffeine would prompt you to burn an extra 15 calories in the day. Research shows that a dose of 3 to 5mg of caffeine per kg of body weight is most effective for boosting your metabolism.

On average, you need to lose around 7,700 calories to lose a kilo. You’d need to consume a lot of caffeine of you’re relying on the stimulant alone to lose weight. Increasing your caffeine intake above the recommended daily dose isn’t the answer though, as excessive caffeine intake can be harmful to your health.

That's why it's important to combine your caffeine supplement with other thermogenic ingredients and a balanced diet, exercise routine and calorie deficit.

Check out the Body Science Clean Coffee Brain Fuel.


Other Common Thermogenic Supplements

Caffeine isn’t the only thermogenic supplement on the market. There are a number of other compounds that work as thermogenics.

Green Tea

Green tea is comprised of two thermogenics — our pal caffeine, and epigallocatechin gallate, or EGCG for short. The combination of these thermogenics has been shown to increase metabolism and fat-burning potential.

EGCG furthers the effects of caffeine because it slows the speed at which adrenaline breaks down. This means the impact of the adrenaline is enhanced (read: the rate at which you burn calories increases).

Green tea supplements that contain caffeine have been shown to increase metabolism by 4% and fat burning by 16% in the day following consumption.

Our Green Tea is full of antioxidants, vitamin c and probiotics, get around a mid to low dose of caffeine before a big day.

Read more on Why you should be taking green tea.


Capsaicin is considered purely thermogenic due to its ability to quickly increase heat in the body. It is the component found in chilli that makes it spicy, so it’s the element responsible for those sweats you get after eating a pepper curry.

There are actually six compounds in the capsaicinoid family, though capsaicin is one of the most potent.

Much like caffeine, capsaicin causes the body to release adrenaline, which in turn accelerates your metabolism and promotes fat burning. It is also an appetite suppressant, so it can cause weight loss by simultaneously burning calories quicker and reducing the number of calories going into your body.

Capsaicin also increases the rate at which your body uses fat as fuel, a process known as fat oxidation. The combination of its oxidative-increasing, metabolic-enhancing, and appetite-suppressing properties makes it a potentially powerful weight loss supplement.

Garcinia Cambogia

Garcinia Cambogia is a tropical pumpkin-shaped fruit that is native to Indonesia. The rind of the fruit is used in both food and medicines. However, it’s most commonly used as an ingredient in weight loss supplements.

The extracts of Garcinia Cambogia are added to weight loss supplements because of the hydroxycitric acid (HDA) content in the fruit. HDA is the primary organic acid in Garcinia Cambogia. This acid essentially interferes with the function of ATP citrate lyase, which is an enzyme in the body responsible for forming fat.

It has also been shown to promote satiety, the feeling of fullness, and increase fat oxidation, as capsaicin does. So, it decreases hunger and fat production, and reduces the number of calories consumed. In these ways, it’s thought to assist in weight loss.

Blended Formulas

Many supplement products contain multiple thermogenic ingredients. These are considered thermogenic blends.

Combining different elements with thermogenic properties may lead to greater weight loss benefits by providing an extra metabolic boost.

Are Thermogenic Fat Burners Effective?

So, are thermogenics effective fat-burners?

The general consensus is that thermogenics will not lead to drastic or rapid weight loss. While they may help to boost your metabolism and prompt fat burning, the effects are considered minimal.

Thermogenics have the best chance of working when combined with exercise and a healthy diet.


Let’s take a closer look at the effectiveness of each thermogenic mentioned above.


The impact that caffeine supplements have on the metabolism is considered quite minimal, and consumption is unlikely to lead to significant weight loss.

However, it may be helpful when combined with an increase in exercise and dietary changes. It’s also been suggested that caffeine tolerance can lessen its fat loss benefits over time.

Higher doses of caffeine, around the 400mg mark, can have an impact, however, such a large dose is not recommended as it may cause undesired side effects.

Read more on Caffeine and Weightloss.

Green Tea

There are limited studies to confirm the effectiveness of green tea as a weight-loss supplement. The research that is available shows somewhat mixed results.

One study reported that overweight people who took green tea supplements every day for 12 weeks lost an average of 0.04kg.

Another study found that over the same 12 week period, the average weight loss was 1.3kg regardless of dosage.

These results are somewhat contradictory, so more research is needed to determine the true efficacy of green tea for weight loss.


The research into capsaicin is a little more promising.

Studies have found that capsaicin can lead to a metabolic boost of around 50 calories per day, which could prompt notable weight loss in the long run.

A different study showed that participants taking 2.5mg of capsaicin with each meal experienced 10% more fat burned in the proceeding day than the control group.

Capsaicin may also reduce stomach fat, with research showing that a 6mg daily dose can lead to slimming in the mid-section over three months.

However, as with caffeine, you can build up a tolerance to capsaicin which can reduce its effectiveness.

Garcinia Cambogia

Research on the effectiveness of garcinia cambogia aiding fat loss is limited and mixed.

Studies did show that taking a garcinia cambogia supplement for 2 to 12 weeks resulted in 1% more weight loss compared to the control group, but more research is needed in this area.


There is currently limited research into the effect that blended formulas have on fat reduction.

A two-month study concluded that overweight people who consumed a blended supplement daily (consisting of green tea extract, capsaicin, and caffeine) lost an extra 0.454kg compared to the control group.

These initial results are promising.

Drawbacks of Thermogenics

Thermogenic supplements are generally considered safe, provided you stick to the recommended dosage and purchase your supplement from a trusted retailer.

However, as with anything you put into your body, it’s important to be aware of the potential side effects and risks.

Side Effects and Dangers

Thermogenic supplements are well tolerated by most people, but it’s possible to experience some undesired side effects.

These include nausea, constipation, stomach pain, headaches, and a minor increase in blood pressure. It’s particularly important to avoid supplements containing 400mg or more of caffeine, as this can lead to increased anxiety, heart palpitations, dizziness, headaches, and irritability.

There have been some reports of complications from thermogenic supplements, including inflammation of the gastrointestinal tract, hepatitis, and liver damage. These complications have been seen in otherwise healthy people.

Key Takeaways

  • Thermonogenics are heat-producing compounds.
  • A thermogenic supplement is made up of an ingredient or multiple ingredients that boost our metabolism and help us burn calories.
  • While many thermogenic ingredients do effectively boost metabolism and promote fat burning, they are unlikely to promote significant weight loss all on their own.
  • To give your thermogenic supplement the best chance of aiding weight loss, it should be taken in conjunction with a healthy diet, calorie deficit, and structured exercise routine.
  • Thermogenic supplements can have side effects, especially if taken in high doses. Ensure you stick to the recommended dose.
  • Ensure you purchase your supplements from a trusted, transparent retailer.

At Body Science, we take care to ensure our products are both safe and effective.

Our range of Shred Ultra Advanced supplements is formulated with herbal ingredients, vitamins, minerals, and amino acids. These elements work together to foster thermogenesis, thyroid function, metabolism, and cognitive function. Our Shred Ultra formula contains the thermogenic ingredients of caffeine and green tea.

Have a question about our blend? Get in touch with us, we’re happy to help!

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