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Weight Loss Supplements

By Josie Porter


Weight loss supplements offer an easy solution to shedding a few pounds. They’re extremely popular, with the weight loss supplement industry being worth billions. But what’s the truth – are these a miracle cure or just another fad?

Weight loss supplements come in a variety of forms, including pills, gummies, powders, and liquids, like teas. They can contain different ingredients, but generally, they claim to speed up metabolism or help to keep us full. 

Let’s discuss some popular ones:

Fat metabolisers 

These products typically contain green tea extract. 

Green tea has high levels of polyphenols, which are compounds that act as antioxidants. Most of these belong to a group called catechins. Proposed mechanisms of these catechins for weight loss relate to fat oxidation and energy expenditure. 

Evidence in humans is mixed and short-term (12 weeks). 

Green tea supplementation at high doses (800mg or above) may be detrimental to health. 

Compounds in green tea may also prevent the absorption of iron from food. 

XLS medical 

Clavitanol is the key active ingredient in this supplement. Clavitanol works to lose weight by blocking the digestive enzymes in your stomach from digesting and breaking down dietary carbohydrates, fats and sugars. 

Research on Clavitanol is sparse. Only one study can be found, which shows weight loss at 12 weeks of use. The researchers had subjects consuming calorie-controlled diet plans and they also had dietary support. It’s difficult to say if the results were a result of the supplement or the support they received.


Ketone supplements claim to mimic ketosis and raise blood ketone levels without having to make changes with our diet. 

Ketosis requires fatty acids, which is how ketosis may help with weight loss. 

There’s some evidence that taking ketone supplements may raise our blood ketone levels. However, there’s no evidence that taking ketone supplements gives us the same benefits of ketosis induced through a low carbohydrate or low-calorie diet. In fact, ketones are also a source of calories, which may simply add unnecessary calories to our diet. 


Capsaicin is what gives chillies their spice. 

This compound is popular for its potential to support weight when supplemented by increasing our metabolism. 

There is some evidence to suggest they may lead to a slight weight loss, but the studies are small and often short in duration. Moreover, the studies often have people making changes to their diet or exercise. 

The large doses required may also irritate our gut too. 


Weight loss supplements sound exciting, after all who doesn’t want quick and easy results? However, like most things, if it sounds too good to be true, unfortunately, it probably is. 

We’re not convinced that they’re worth our hard-earned cash. Often the results are not that impressive and supplements are often paired with lifestyle changes too. 

If you’re looking for support with weight loss, I’m happy to help in the clinic, and so is Tabitha and Laura depending on your circumstances. 

For people living with a higher BMI, there are medications that are evidenced to support weight loss; these can be great options. These are not to be confused with over the counter supplements discussed in this article!

Josie is a registered dietitian, specialising in weight management, bariatric surgery, type 2 diabetes and women’s health. Josie has a wealth of experience working in some of the top trusts in London, both clinically and in research.

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