Losing weight can be tough. It requires consistently eating healthily and exercising; sometimes it can feel like fighting a losing battle.

It’s not surprising then that reaching for the many weight-loss supplements you can buy over the counter can be tempting. 

Experts caution, however, that supplements are often expensive, unregulated and in most cases won’t make any significant difference to our weight. Scientific research is limited and often paid for by the manufacturers.

“Weight loss supplements, unlike prescription drugs, are unregulated and don’t have to be effective to be sold. I don’t know of any supplements marketed for weight loss that deliver on the promises and are effective for healthy, sustainable weight loss,” says Dr Federica Amati, the head nutritionist at Zoe, the science and nutrition company.

Other experts point out that even though some supplements can help with weight loss, they will only work as part of a healthy diet and exercise regime.  

“You can’t rely on weight loss supplements alone to lose weight. Sadly, many claim to be the panacea for weight loss. Short cuts don’t exist and if it sounds too good to be true, then it probably is,” says Dr Samantha Gill, a specialist gastroenterology dietitian.

If you’re considering trying them, read on to find out how they work, what they contain and whether they are safe to take. 

How do weight loss supplements work? 

Weight loss supplements claim to work in one of three ways: they either limit our absorption of fat from foods, speed up our metabolism to burn more calories or make us feel fuller so we eat less.

The supplements contain a mixture of natural and artificial compounds and different brands use different combinations. Read on to find out more about the most commonly used ingredients.

Caffeine

Caffeine is good for our health, provided it agrees with you, and is a common ingredient in weight loss supplements. On its own, it can improve concentration, memory and workout performance, and it is associated with weight loss because it speeds up our metabolism. However, it won’t bring about weight loss on its own, and we may become tolerant to it over time.