Burn XT Ingredients: The Five Actives and Their Amounts

Carnitine is a compound the body already makes from lysine and methionine, and it also arrives in the diet, mostly from red meat. Its job inside a cell is transport: it carries long-chain fatty acids across the mitochondrial membrane so they can be used for fuel. The acetylated form crosses into the brain more readily than plain L-carnitine, which is why it turns up in focus products as often as in gym products.

This is the largest amount on the panel and the one with the most trial data behind it, though not the most flattering. A meta-analysis of 37 randomised trials found L-carnitine supplementation produced a small average reduction in body weight and body-mass index, with the effect shrinking as trial duration grew. An earlier meta-analysis reached the same shape of conclusion: statistically detectable, clinically modest. Most of those trials used 1,500 to 3,000 mg a day, which is two to four times what this panel prints.

Two honest points. The trials were mostly in people with obesity or a metabolic condition, and the NIH fact sheet is blunt that healthy people with normal carnitine status have little to gain from more of it. And 700 mg is below the amounts used in almost every trial that reported an effect.

Sources: Talenezhad 2020 · Pooyandjoo 2016 · NIH ODS carnitine

Green tea extract concentrates the catechins from the leaf. This panel prints the standardisation, which many labels do not: 98 percent polyphenols, 45 percent EGCG and 75 percent catechins. At 450 mg that works out to roughly 200 mg of EGCG and about 340 mg of total catechins a serving, which is a genuinely useful number to be given.

Catechins plus caffeine is the best-evidenced pairing on this label. A 1999 crossover study found a green tea extract supplying 90 mg EGCG with 50 mg caffeine raised 24-hour energy expenditure by about 4 percent, and that the same dose of caffeine alone did not. A meta-analysis of catechin-rich teas later found a significant increase in energy expenditure and fat oxidation, with the effect blunted in habitual caffeine consumers. A Cochrane review of green tea preparations for weight loss found the effect on body weight small and not clinically important.

A 4 percent shift in 24-hour energy expenditure is real and it is small: on a 2,200 calorie day it is about 90 calories, which a single snack erases. And the Cochrane reading matters more than the mechanism study, because it asked the question a buyer is actually asking.

Sources: Dulloo 1999 · Hursel 2011 · Jurgens 2012 (Cochrane) · Berube-Parent 2005 · NCCIH green tea

Anhydrous simply means dried: it is caffeine with the water removed, so it can be weighed accurately into a capsule. The panel prints 135 mg a capsule and 270 mg for the two-capsule serving. For scale, a 12-ounce mug of brewed coffee is usually 95 to 165 mg, so the full serving is roughly two to three mugs taken in one swallow.

Caffeine is the ingredient on this label with the least doubt attached to it. It reliably raises alertness, it reliably raises resting energy expenditure for a few hours, and it reliably suppresses appetite a little. A 24-hour chamber study of a thermogenic beverage measured the effect on whole-day energy metabolism rather than on a single afternoon, which is the honest way to measure it.

The FDA's consumer guidance puts 400 mg a day as the amount not generally associated with negative effects in healthy adults. One full serving of this product is 270 mg of that, before any coffee. The back label says plainly: do not consume with other caffeine sources, do not exceed four capsules in 24 hours, and avoid taking it within six hours of sleep. A randomised study of 400 mg caffeine taken six hours before bed still measured a meaningful loss of sleep, so that six-hour line is not decoration.

Sources: FDA on caffeine · Drake 2013 · Mesas 2011 · Rudelle 2007 · MedlinePlus caffeine

Capsimax is a branded, coated capsicum extract. The coating is the point: raw capsaicinoids at a dose high enough to do anything are hard on the stomach, and the beadlet delivery is designed to release them further down. The panel prints the branded name and the total extract weight, but not the capsaicinoid content, so the active load cannot be checked from the label.

A systematic review and meta-analysis of capsaicinoids and capsinoids found a measurable increase in energy expenditure in healthy adults, and a second meta-analysis of human studies reached a similar conclusion for body composition endpoints over time. Both describe small effects.

Two milligrams of capsaicinoids is a common effective dose in that literature, and this label prints 50 mg of extract with no capsaicinoid figure beside it. A branded ingredient with an undisclosed active fraction is not the same as a disclosed dose, and nobody reading this label can compare it to the trials.

Sources: Irandoost 2021 · Zsiboras 2018

BioPerine is a standardised piperine extract, and it is in this formula as a helper rather than an active. Piperine slows some of the liver and gut enzymes that clear other compounds, so whatever it is taken with tends to stay in the blood longer.

The reference study is from 1998: 20 mg of piperine raised the bioavailability of curcumin in human volunteers by a very large margin. That result is real, it is old, and it is about curcumin, not about anything else on this panel.

Two things follow, and the second one matters more. Five milligrams is a quarter of the amount in that study. And the same enzyme effect applies to medicines: piperine can raise blood levels of drugs cleared by the same pathways, so this is a real reason to talk to a pharmacist rather than a detail to skim.

Sources: Shoba 1998 · NCCIH on using supplements