Thermogenic - Risks and Side Effects

The so-called thermogenic supplements are products that have become very popular in recent years because it promises weight loss and better physical performance. The thermogenic substances which act by increasing the body temperature through stimulation of the cardiovascular, respiratory and central nervous systems. The thermogenesis results are an increase in the basal metabolism and an increased fat burning, which helps the patient to lose weight.


The problem is that the results of these supplements are not free from side effects, some of them simple, such as mood changes, dry mouth, tremors and insomnia, and other more serious conditions such as heart arrhythmias, heart attack and stroke.

In recent years, several government agencies control substances, including the Brazilian ANVISA, has issued resolutions prohibiting the sale of some thermogenic supplements due to their risks to health. With each passing year, the list of banned products have increased.

In this article we make a review of the thermogenic supplements, addressing its composition and possible side effects.

Caution: for there is no confusion, we must note that we will talk exclusively about thermogenic supplements, which are industrial products sold in the form of capsules or tablets. The text will not address the issue "thermogenic foods," as these, if consumed in a balanced way, do not bring health risk.

What is a thermogenic supplement?

We call thermogenic supplement substances that help boost metabolism and increase body temperature, helping to burn fat and weight loss.

The strong appeal in the media and the expected weight loss with quick results have contributed to irresponsible use of these substances by the population without it to be properly informed about the risks involved. For this reason, government agencies around the world have closed the siege against the indiscriminate sale of these products.

The composition of thermogenic supplements has been changing over the years due to the frequent updating of the list of banned substances commercially. The constant removal of unsafe thermogenic supplements has resulted in two effects: greater security for users, but at the cost of a significant loss of slimming effect.

Substances that have great stimulating activity of metabolism, such as ephedrine and Dimethylamylamine (DMAA), present in various brands of thermogenic, were banned in several countries, including Brazil, because of the high risk of cardiovascular complications. Currently, the most popular thermogenic use caffeine and synephrine (Citrus auranthium) main thermogenic substances.

Besides sifedrina and caffeine, it is possible to find many other products considered in the thermogenic substances, including hormones, vitamins, amino acids, and even diuretics, antidepressants, which makes it impossible to set a standard composition for different brands of thermogenic supplements.

Often substances in thermogenic supplements

Because there are several different brands, with completely different compositions, let's do a survey of the main substances in thermogenic supplements most sold in Brazil and worldwide.

Note: Often, the active substance is not clearly described on the product label, being masked by using the scientific name of the plant that gives rise to it. Whenever possible, describe the name of the active substance and its source plant for easy identification.

a) Ephedrine - ephedrine (ephedra) is a substance derived from the plant Ephedra sinica or Ma huang. Molecularly similar to amphetamine, ephedrine was widely used by the caffeine as thermogenic supplement, aimed at weight loss and increased athletic performance. Despite its high efficiency and popularity, thermogenic ephedrine base has been banned worldwide due to the high risk of side effects.

A study conducted between 1997 and 1999, with users of the thermogenic ephedrine base, found several cases of hypertension, cardiac arrhythmias, myocardial infarction, cerebrovascular accident (stroke) and seizures. At least 10 cases evolved to death and 13 led to permanent disability. Of these 23 most serious reports, nine occurred in people who had no risk factors and had consumed the doses recommended by the manufacturer.

b) Caffeine - caffeine is the most consumed stimulating substance in the world and has been used almost universally in the commercial thermogenic allowed. Studies show that the consumption of caffeine to 400 mg per day is safe in adult (30 ml espresso coffee has between 30 and 90 mg of caffeine). In adolescents an amount of safe daily caffeine has not yet been established but it is probably less than the limit of 400 mg in adults.

Caffeine is not as effective for weight loss as those banned substances derived amphetamine, which makes its dosage in thermogenic be quite high in order to compensate for the low efficiency. Some thermogenic products arrive to give more 800 mg of caffeine per day, which is more than twice the dose considered safe. Very high doses increase the risk of arrhythmias and cardiac ischemia.

Caffeine in thermogenic is usually obtained through ground coffee beans, guarana and green tea.

c) Synephrine - Synephrine, obtained by Citrus auranthium, also known as bitter orange or orange-bitter, is a substance similar to ephedrine, but weaker. With the ban of ephedra, synephrine has gained popularity and has often been used in combination with high doses of caffeine.

Although weaker and less effective as ephedrine, synephrine can in no way be considered a substance without risk. Stroke cases, cardiac arrhythmias and heart attacks have been reported due to their use.

The maximum daily dose considered safe for synephrine is 50 mg. When combined with caffeine, the safe maximum daily dose is 40 mg of synephrine and 320 mg of caffeine.

d) Octopamine - Octopamine is a substance similar to synephrine, which can also be obtained by Citrus auranthium. The efficacy and the risks are very similar. Doses up to 50 mg / day are considered safe.

e) 1,3-dimethylamylamine (DMAA) - A 1.3-dimethylamylamine (DMAA) is a type of amphetamine, which was banned by ANVISA in 2012.

The DMAA can cause a number of side effects such as agitation, dizziness, headache and elevated blood pressure. Case reports point to DMAA as a cause of cerebral hemorrhage, drug-induced hepatitis, rhabdomyolysis and myocardial infarctions.

f) Other substances: chitosan, chromium, ginseng, glucomannan (Amorphophallus Konjac), L-carnitine, psyllium, St. John's wort, taurine and linoleic acid are often substances in thermogenic, usually in combination with caffeine and / or synephrine. These substances, however, have no scientific evidence that are effective for weight loss or increased athletic performance, and may still cause side effects and interact with some drugs.

Care before taking a thermogenic supplement

No thermogenic supplement should be consumed without support from a dietitian or medical professional. Even products authorized by ANVISA may cause serious side effects if consumed by people with risk factors for cardiovascular disease or if the stimulants are in very high concentrations.

A care that must be taken is always trying to identify all substances in the product, with their respective strengths. Products not authorized by ANVISA may have hidden substances in its formula, especially diuretics, thyroid hormones and antidepressants.

As mentioned above, in recent years ANVISA has withdrawn a number of thermogenic supplements, especially those with DMAA or ephedrine in its formulation.

Examples of banned thermogenic are:
  • Jack3d
  • Oxylin Pro
  • 1MR
  • Oxy Elite Pro
  • Lipo-6 Black
  • PWR
  • Hemo-rage
  • SSIN

Some of these brands have changed their formulas, removing the substances banned by ANVISA, and therefore can still be found in the market.

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