Thermogenesis is the process of heat production by the body. Most body heat is a by-product of metabolism. These reactions increase during exercise, consequently there is a greater risk of overheating. During cold weather, extra internal heat may be generated by increasing metabolism (non-shivering thermogenesis), and by uncontrolled muscular contractions (shivering thermogenesis). Non-shivering thermogenesis involves stimulation of metabolism by the sympathetic nervous system.

Various supplemental agents, either synthetic or from herbal origin, are marketed as thermogenic “fat burners”.  The most popular “fat burner” supplements ever on the market were no doubt ephedrine-based products. Ephedrine is a drug derived from ephedra naturally found in Ma Huang and Sida cordifolia. The chemical structure is similar to amphetimines and works as a “beta – adrenergic agonist”. This means that it stimulates the metabolism via the sympathetic nervous system. 

Ephedrine and caffeine were often found in combination, which have been proven to be more effective and is known as the EC stack. Sometimes aspirin (acetyl salicylic acid and other salicylates which are naturally found in White Willow bark) is added to prolong the effect of ephedrine in the body. It is known as the ECA stack.

Ephedrine was immensely popular because there was some scientific evidence showing some measurable fat burning effects, but only in the short term. Users could also feel an energy rush. The increased heart rate, energy, amplified mental focus and workout intensity made it extremely popular as a “pick me up” supplement, but also susceptible to abuse.  Ephedrine was essentially a legalized mild form of speed. Like any drug, the cessation of ephedrine use is characterised by withdrawal symptoms and one experiences an emotional and physical “crash” leading to addictive behaviour.


Finally, after almost 2 decades of inaction despite convincing evidence of the health risks associated with Ephedrine use, the FDA (Food and Drug Administration) fulfilled their legal responsibility to safeguard public health and banned Ephedrine alkaloids.

After it was banned, supplement companies marketing fat-burning products, started to market ephedra-free supplements with ingredients such as Synephrine (naturally found in Citrus aurantium) and Yohimbine, commonly known as pseudoephedrine which are at best unproven, watered down alternatives for ephedrine providing a slight buzz notably through the inclusion of ingredients such as caffeine. The side-effects of pseudoephedrine are similar to that of ephedrine, but milder. This includes, but is not limited to, gastrointestinal symptoms, nervousness, headache and insomnia.

Because of the negative connotation and bad publicity surrounding ephedrine and pseudoephedrine, it is often disguised with herb names from which the average consumer cannot tell the difference.

As a general rule of thumb, athletes should refrain from any supplement that bears the words “fat-burner”, “fat-burning agents” or “thermogenic agents”. All the ingredients used in PVM products are deemed legal by WADA.



It is a misconception that you must use a “fat burner” to lose fat.  Even if short term fat loss is attained it will not lead to permanent fat loss. To lose fat permanently one has to treat the causes and not the symptoms!  In nature one cannot get anything for nothing.  To affect a permanent change one has to perform work, by either working harder and or smarter.  Success cannot be achieved without working to achieve one’s goals.  We should all be intuitively aware of this fact but few people are aware that empirical scientific evidence for this phenomenon exists in nature through the Law of Entropy Production (2nd law of thermodynamics).

The Law of Entropy Production is arguably the most important law in all of the natural sciences and has been subjected to more empirical falsification than any other law in nature. Arthur Eddington eloquently wrote:

"The law that entropy always increases - the second law of  thermodynamics - holds, I think, the supreme position among the laws of nature. If somebody points out to you that your pet theory of the universe is in disagreement with Maxwell's equations - then so much the worse for Mazwell's equations. If it is found to be contradicted by observation - well, these experimentalists do bungle things sometimes. But if your theory is found to be against the second law of thermodynamics I can give you no hope; there is nothing for it but to collapse in deepest humiliation."


Why was he so sure about this? Was all the intended falsification of the law done by scientists? No! It was done by ordinary people because so many people have a passionate desire for an “eternal slave” – something that can deliver work without costing anything.  A thermogenic fat burner is nothing more and nothing less! Even worse you pay for it!

Although there is evidence for some thermogenic agents to produce mild appetite suppressant effects and modest short-term weight-loss, permanent body fat loss over a period of time after cessation of use has not been established.

Homeostasis dictates - The more potent the thermogenic agent the worse the symptoms and side effects!

There exists a relative constancy in the internal environment of the body that is naturally maintained by adaptive responses that promote healthy survival (i.e. homeostasis). Various sensing, feedback and control mechanisms function to affect this steady state. Thermogenic substances normally disturb more than one of these mechanisms, and then the body reacts to this through its normal adaptive responses, i.e. long-term use may be ineffective because the body may adjust to the increased metabolic rate. In time the body adapts to the ingested levels of the substances and then becomes resistant, leading to a higher requirement of the substance in order to achieve similar stimulatory effects than before. This applies also to the stimulatory effect of thermogenics to increase mental alertness and to produce feelings of euphoria.

Thermogenic agents are associated with several side effects such as heart palpitations, gastrointestinal symptoms, nervousness, headache, insomnia, dizziness, tremors, seizures, skin flushing, tingling, as well as hypertension, arrhythmias, and tachycardia. Products containing ephedrine can cause serious adverse effects especially in those individuals with underlying heart disease, hypertension, diabetes, prostate dysfunction and those taking monoamine oxidase (MAO) inhibitors or other sympathomimetic agents (eg, decongestants, beta agonists, caffeine and phenylpropanolamine). Synephrine products are mild thermogenics and therefore seem to have fewer side effects and possibly less thermogenic properties. Yohimbine acts as a potent vasoconstrictor and can raise blood pressure.


Long-term body fat loss can only be achieved with appropriate training programmes and dietary strategies. Dietary supplements should not replace healthy eating habits. It may form part of a healthy diet if used appropriately because it is convenient and may help to increase or decrease one or more macro-nutrient. 

It is PVM’s policy not to produce any thermogenic fat burners. It is however our opinion that supplement companies will continue to market thermogenic fat burners and that many consumers will continue to consume them for as long as:

  • Money/Greed continues to motivate the supplement industry
  • Legislation does not put the onus on supplement companies to scientifically prove efficacy and safety of their product and claims
  • There is a lack of scientific knowledge and a frame of reference among consumers to make informed decisions regarding health
  • Consumers remains susceptibility to falsely believe the advertising of supplement companies

+++ PVM sub-contracted to condition the Free State Cheetahs rugby players...     A first in South Africa. Olympic rower Jen Hodsen, trained by PVM is competing at the World Rowing Championships at the end of August.      Pseudoephadrine now banned by WADA!      Athletes be informed of the dangers of using thermogenic fat burners.      New improved Octane Gel will be available soon! New Octane Gel now also available in delicious Chocolate flavour Check out iSnack Whole Nutrrition on the Go!      iSnack is the latest Nutritech, Smart Food addition to the PVM range iSnack is the perfect On The Go nutritious snack +++