You've seen them on being sold in the internet, stacked up in high-street stores and touted by exhausting Instagram fitness personalities — but, chances are, you don't know enough about fat-burning supplements, fat binders and fat pills.

(Related: This legal pill could help you get bigger muscles)

Promising to annihilate unwanted inches on your waistline and to detonate body fat percentage in record time, yearly sales for fat-burning supplements often exceed £900m in the UK, meaning a significant portion of the health and fitness population is relying on questionable ingredients to get quicker results and an even faster six-pack.

(Related: How Ibuprofen could be stunting your muscle growth)

But what's actually inside fat-burning supplements and can you really trust them? Below, we take you through it.

What are fat-burning pills?

Designed to give you a boost in your fat-burning potential, fat-burners are marketed around increasing metabolism, boosting energy and reducing your appetite — a trifecta of solutions that translate to weightloss.

(Related: Want to lose weight? Cut back on these 'healthy' foods)

What most people don't realise, however, is that your best-ever body is primarily made in the kitchen — fat-burning supplements alone won't get to your goals if you're diet isn't 'clean' enough.

(Related: The weird ingredient that could help you lose 4kg in 10 weeks)

Designed to supplement your diet, most fat-burning pills often include CLA — Conjugated Linoleic Acid, a polyunsaturated fat found in meat sources — black pepper, proven to reduce development of fat cells, and L-Carnitine Tartrate, an amino acid which helps the body use fat as a source of energy.

(Related: 5 of the best exercises for burning belly fat)

Once taken, fat-burners cause the release of two hormones — epinephrine and norepinephrine — to mobilise fat from fat stores into your blood stream, to then be burned through exercise.

What are fat-binders?

Fat-binders, unfortunately, are considerably less glam than fat-burning pills. While fat-burning pills focus on dealing with fat inside your body, fat-binders use the digestive tract to excrete fat.

(Related: The best whey protein)

Put simply, fat-binders prevent some fat being absorbed — and therefore stored — by trapping and sticking fat molecules and encouraging passage out of the body through your anus.

(Related: 7 healthy snacks that will suppress your appetite)

Essentially, you sh*t out your fat, so be warned — they also gobble-up muscle-maintaining vitamins A, D, E and K, according to research at the University of Oxford's Centre for Evidence Based Medicine.

Alternatives to fat-burning pills

By now, we hope, you'll have figured out if fat-burning pills or fat-binders are for you. If they sound a little suspect, there are alternatives. Green tea extract, for example, is a considerably more natural option for giving your metabolism a kick.

(Related: I tried intermittent fasting for a week — here's what happened)

Similarly, ginger holds the power to spice-up your weightloss by doubling the speed at which protein can reach your muscles. How's that for suspect science?