Supplements create short-term success and are not the answer.

Supplements that claim to stoke or speed up the metabolism have been around for decades and currently go by the name thermogenic or metabolism boosters.   They are currently one of the most popular weight loss supplements in the world, and the supplement companies have billions invested in advertising for them.  Although they are quite dangerous, they will never be outlawed because the supplement industry is very vested in lobbying our government to keep them off the hit list.

Manufacturers claim that thermogenic supplements are designed to increase your metabolism and burn calories without exercise or at least at a rate higher than without them and thus promote weight loss.   They also are reported to suppress your appetite. The claim is that they increase your body temperature or heat and thus increase calorie usage.   These supplements include a variety of stimulants from herbs. These stimulants caffeine, synephrine, or ephedrine which purportedly increase energy levels, suppress appetite, and burn fat.  

So what do they do?  These supplements cause such side effects as irregular and rapid heart rates, insomnia, and elevated blood pressure.  Although they may increase calories burned by a nominal amount, the increase in blood pressure and pulse have a deleterious long-term effect that is not worth the temporary nominal increase in calories burned.  As far as weight loss is concerned, it is a minimal amount, and very few have any lasting weight loss because they gain every pound back once they stop taking supplements.

Research:

1. The proof is in the research.  One study, Omar Said,  showed that it caused 21 lbs (9.5 kg) of weight loss over a 3-month period while taking a thermogenic supplement​[1]​.  Although it may appear a miraculous amount of weight loss, I would argue that this is not any more than I would expect if the subject had religiously followed a diet.  I would expect 2 pounds per week average weight loss and about 24 pounds with or without the supplement.  
2. Another study looked a meal replacement supplementation and thermogenic supplements in college age men and women.  It found that meal replacement improve fitness, but adding a thermogenic substance provides no additional benefit over fitness or body composition changes​[2]​.

The bottom line: I can sum up my thoughts on thermogenics and metabolism boosters in one statement: Toss them in the trash. They are not worth the risk to your health.  

I will post more on individual elements of thermogenic as I write more.