- Thermogenic Fat Burners (often appetite suppressing)
- Stimulant Free Fat Burners (or "stim-free fat burners")
- Fat blockers
- Thyroid Based Fat Burners
Most fat burners are "thermogenic" and aim to increase your base metabolic rate by a few percentage points so your body burns more calories than it would do otherwise. An advantage of thermogenic fat burners is that they will often decrease appetite (and reduce cravings), whilst also improving energy levels.
Stimulant free fat burners, fat blockers and thyroid based fat burners can be stacked with thermogenic fat burners to increase their impact and the success of the supplement stack. Stim-free fat burners will improve the rate at which your body burns fat, without antagonising your beta receptors, and are useful for those creating a fat-loss stack or who have pre-existing hypertension and don't wish to chance elevating it. Fat blockers reduce the amount of fat (or in some case carbs) absorbed at each meal. Thyroid based fat burners up-regulate and optimise the activity of your thyroid to improve loss of stubborn fat - they're great for the last few weeks of a diet, but you should ensure you take long breaks between "cycles" since they're also quite powerful.