People have used capsaicin, tea, and caffeine as thermogenic supplements to help burn fats for a long time. Knowing how effective such supplements are helps you know if using them really adds value.

The quest for weight loss is more popular today than ever, with many people being concerned about their health, others doing it to be fit, and still, some being interested in having the right figure for the beauty industry. One way to lose weight is burning the excess fats, a mission people apply different missions to accomplish. For instance, while some work out and do exercises, others use thermogenic supplements whose natural ingredient contents are believed to boost metabolism and contribute to burning. That said, you may wonder whether the supplements are good enough to reduce fat weight, a question this article tries to answer.

Understanding thermogenic supplements

Before looking into whether thermogenic supplements are really effective for reducing body fat, understanding what they are is important. The term thermogenic comes from the word ‘thermos,’ meaning heat; hence the supplements can also be called ‘heat-producing supplements.’ The description is appealing since they boost metabolism and produce heat in the process. There are thermogenic supplements, most of which you can source over the counter. While some contain several metabolism-boosting compounds, others are made of a single ingredient. Although marketers praise the supplements and have a lot to say about how incredibly they can assist you with fat burning and weight loss, evidence may say otherwise, which is why their effectiveness is highly debated.

Reviewing what the existing studies say about thermogenic supplements

Reviewing what available research says about thermogenic supplements helps you know whether they are really effective and if you can expect to lose weight and burn fat with them. Here is what studies say about various thermogenic supplements;

i. Thermogenic blends

Thermogenic blends are made by combining several thermogenic compounds together to have a synergistic effect. For instance, manufacturers have combined caffeine, tea, and capsaicin, resulting in more fats being burnt, especially when used besides exercising. Still, there are limited studies on the effectiveness of thermogenic blends. One study showed that after eight weeks of taking thermogenic blends and exercising, a study group experienced more 0.45kg weight loss than the placebo group.

ii. Capsaicin

Capsaicin is the spicy-making molecule in chili peppers, and the greater its content, the spicier the chili peppers. It has two fat-burning mechanisms, including reduced appetite, which means reduced food intake. It also triggers the production of adrenaline, increasing metabolism, hence fat burning. One study showed that when participants took 6mg capsaicin daily for three months, their belly fat significantly reduced. However, the body can get used to it, making it less effective.

iii. Yohimbine

Yohimbine is extracted from the African Yohimbe tree and is usually taken as a thermogenic supplement that supposedly boosts metabolism when combined with exercise. Currently, studies on its effectiveness are quite limited, although one particular study showed that after two weeks of supplementing with it, participants had 2% less body fat. When taken with exercise, it boosts noradrenaline, adrenaline, and dopamine hormones which supposedly boost metabolism and promote fat burning.

iv. Caffeine

 Caffeine is a natural stimulant found in tea, coffee, guarana, and many other plants and fruits. Since it can promote adrenaline production, which triggers the fat cells to release fatty acids for energy production and calorie burning, it is usually taken as a good thermogenic supplement. Studies show that taking 1mg of caffeine helps one lose 15 calories over the next 24 hours. The recommended dosage is 3-5 mg/kg, although the effect is minute and can only be felt when the caffeine pills are coupled with dietary adjustments and exercises.

v. Bitter orange

There are many citrus fruits, one of them being bitter orange which is used as a thermogenic supplement. It contains a compound called synephrine, whose structure resembles ephedrine. Ephedrine was used to boost metabolism and fat burning, but when it caused heart-related deaths, it was banned in the USA. However, synephrine has not had negative side effects, and its 50mg dosage results in 65 calorie losses in 24 hours. Still, there is a need for human studies to establish whether it can help human beings lose weight.

vi. Green tea

Green tea has epigallocatechin gallate (EGCG) and adrenaline, two compounds it uses to burn fats. As adrenaline triggers energy by sending impulses to fat cells to produce fatty acids, EGCG prevents adrenaline breakdown, amplifying its function. Although studies have shown that it can boost metabolism and fat burning by 4% and 16%, respectively, there are no proofs that these effects ultimately lead to overall fat and weight reduction.

Thermogenic supplements: safety and side effects

The above section examined the various thermogenic supplements and what studies say about them. It’s time to learn about their safety concerns and side effects, including;

a. Undesirable side effects

While some people may tolerate thermogenic supplements, others are negatively affected and experience unpleasant side effects like headaches, nausea, and stomachaches. In some cases, people’s blood pressures have slightly increased, while those taking more than 400 mg of caffeinated thermogenic supplements have complained about restlessness, dizziness, and palpitations.

b. They are not well-regulated

While most food and medicine may be regulated by health agents, most supplements are not. Therefore, they could not be safe, and their distribution may also be corrupted, hence the need to speak to your doctor before trying supplements, especially those with multiple compounds, and could result in serious reactions.

c. Serious complications

Besides the undesirable side effects, some people have reported serious medical complications, including liver inflammation, damage, and failure. In addition, healthy teens have had such conditions deteriorating, even necessitating surgery.


Thermogenic supplements are usually taken to boost metabolism and increase fat burning. Although marketers praise them a lot, studies reveal otherwise, necessitating further research before most of them can be recommended for fast weight reduction. They are also associated with negative side effects like liver damage and failure, besides undesirable side effects like headache, stomachache, and nausea.

Nutritionist, Cornell University, MS

I believe that nutrition science is a wonderful helper both for the preventive improvement of health and adjunctive therapy in treatment. My goal is to help people improve their health and well-being without torturing themselves with unnecessary dietary restrictions. I am a supporter of a healthy lifestyle – I play sports, cycle, and swim in the lake all year round. With my work, I have been featured in Vice, Country Living, Harrods magazine, Daily Telegraph, Grazia, Women's Health, and other media outlets.

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