Ripped Fuel Review
Extreme Ripped Fuel and Ripped Fuel 5X Reviews
Ripped fuel by Twinlab Supplements is a fat burner that has had a rather long history, where the earlier versions had contained the ECA stack. It's formula has undergone various changes over the years, and it has also branched out to slightly different versions as well. There is the original Ripped Fuel, Ripped Fuel Extreme, and also Ripped Fuel 5X. While these do contain some similar ingredients, overall, their formulas are quite different, and we'll discuss some of their ingredients here.
We'll start off with the basic formula here.
The key ingredients contained in the basic formula include vitamin D, chromium picolinate, cayenne, milk thistle, green tea, guarana, and yerba mate. Chromium Picolinate is a trace mineral that you may find in various diet supplements, such as Ripped Fuel. There are various claims stating that CP helps with weight loss, improves body composition, and enhances fat reduction. However, there's little evidence to support these claims, and on the contrary, many studies have indicated that there's little to no apparent benefit of using CP for weight loss - although it may be of some benefit for suppressing appetite. Read more about chromium picolinate here in detail.
Milk thistle is a herb commonly used for liver support, and is also used to counteract alcohol's harmful effects on the liver. There is also one study that finds milk thistle may inhibit the development of young fat cells into adult fat cells.  However, there is still very little evidence to suggest that milk thistle is an effective weight loss supplement. Both Guarana and Yerba Mate are stimulants that contain caffeine. Guarana is rich in caffeine that is often consumed as a potent energy booster, while yerba mate also works as an energy booster and helps improve focus. It is often consumed as an energy drink and tea. We have detailed articles about both of these, so we won't go in any more detail here.
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Twin Lab Ripped Fuel Extreme Review
Extreme ripped fuel by Twinlab contains some common ingredients with the basic version, but it also comes with several additional and different ingredients. The key ingredients here are calcium, chromium, cocoa seed extract, green tea extract, caffeine, cayenne fruit, and l-carnitine. There are several sources of caffeine in this formula as well, for example, cocoa seed, green tea contains minor amounts of caffeine, and also 220mg of caffeine, which is equivalent to about 1.5 to 2 cups of coffee.
The Cocoa extract in Extreme Ripped Fuel has been standardized for 10% theobromine, caffeine, tyramine, and phenylethylamine (PEA). These all have certain effects for fat loss, and theobromine and PEA can be found in foods such as chocolate and are stimulants with an effect on the central nervous system. There are also some studies that have found Cocoa extract to lower serum glucose levels, reduce total cholesterol levels, and lower total triglycerides in rats. 
Finally, L-carnitine helps the transport of fatty acids into the mitochondria to generate energy. It is widely promoted and sold as a weight loss and sports supplement, however, there does not appear to be much scientific support for this. There are some scientific studies that have found L-carnitine to help improve exercise performance by increasing muscle total carnitine resulting in glycogen sparing during exercise. 
Twinlab Ripped Fuel 5X Review
Finally, we have the Twinlab Ripped Fuel 5x version fat burner. Looking at its formula, it is quite different from both the other two versions. In contains various B vitamins such as thiamine, niacin, pyridoxine, and vitamin B12, along with calcium, chromium, caffeine, and a 5x potentiator blend together with a 5x thermo energetic blend. This formula was designed to increase calorie burning, preserve lean muscle mass, lower body fat, and also increase energy levels.
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1. Int J Mol Med. 2009 May;23(5):633-7.
Silibinin attenuates adipogenesis in 3T3-L1 preadipocytes through a potential upregulation of the insig pathway.Ka SO, Kim KA, Kwon KB, Park JW, Park BH.
2. J Ethnopharmacol. 2005 Apr 8;98(1-2):55-60.
The effect of Malaysian cocoa extract on glucose levels and lipid profiles in diabetic rats.Ruzaidi A, Amin I, Nawalyah AG, Hamid M, Faizul HA.
3. J Physiol. 2011 Feb 15;589(Pt 4):963-73. Epub 2011 Jan 4.
Chronic oral ingestion of L-carnitine and carbohydrate increases muscle carnitine content and alters muscle fuel metabolism during exercise in humans.
Wall BT, Stephens FB, Constantin-Teodosiu D, Marimuthu K, Macdonald IA, Greenhaff PL.