Let’s talk about weight loss 

And the rise of Wegovy et al… 

Wegovy [other drugs are available] has transformed the conversation around obesity.  

For many people, it offers real hope after years of struggling with weight. But they are not suitable for everyone. Some people experience intolerable or serious side effects; others have medical contraindications, cannot access them, or simply do not wish to use long-term injectable medication. 

I was talking to some students about these injections recently. Although they recognised the use for some people at serious risk of mortality due to complications of obesity, they were concerned about the side effects they had heard about from people using this intervention. 

So, I got to thinking. Is there anything we could suggest to obese people before they take the decision to use Wegovy et al? 

One plant that could deserve attention in this space is yerba maté (Ilex paraguariensis), a traditional South American beverage with a long history of use for appetite, energy and metabolic health. There are good reasons why yerba maté is increasingly studied in relation to obesity and weight management. 

Yerba maté is a caffeinated herbal infusion made from the leaves of Ilex paraguariensis, traditionally consumed in Argentina, Uruguay, Brazil and Paraguay. It contains a complex mix of bioactive compounds, including: 

• Caffeine and theobromine 

• Chlorogenic acids (also found in coffee) 

• Saponins (bitter triterpenes) 

• Polyphenols and flavonoids 

Unlike coffee, maté tends to produce a more sustained stimulation, often described as ‘alert but calm’, which may already make it more usable for people sensitive to caffeine spikes. 

AND: one of the most consistent findings in maté research is its effect on appetite and satiety. 

Several human studies have found that yerba maté can increase feelings of fullness and reduce short-term food intake.  

How? 

• Modulation of gut hormones such as GLP-1 

• Delayed gastric emptying (in some preparations) 

• Central effects on appetite signalling 

This is particularly interesting because GLP-1 is exactly the pathway targeted by drugs like Ozempic and Wegovy. Yerba maté does not act as a pharmaceutical GLP-1 agonist, but it may gently enhance endogenous satiety signalling through diet-derived compounds. 

For people who cannot use GLP-1 drugs, even modest improvements in satiety can make behavioural change more realistic and sustainable. 

Yerba maté also appears to influence lipid/fat metabolism. 

Animal and human studies suggest maté may: 

• Reduce fat accumulation 

• Increase fat oxidation 

• Improve lipid profiles (lower triglycerides and LDL) 

• Downregulate genes involved in adipogenesis (fat cell formation) 

Some of this effect is likely due to chlorogenic acids, which are known to influence glucose absorption and insulin sensitivity, and some to saponins, which interact with bile acids and fat digestion. 

This means maté is not only acting on appetite, but also on how the body processes and stores energy. 

Obesity is tightly linked with insulin resistance. Even small improvements in glucose handling can make weight loss more achievable. 

Yerba maté has been shown in several studies to: 

• Reduce post-prandial glucose spikes 

• Improve insulin sensitivity 

• Support better glycaemic control in people with metabolic syndrome 

Again, this mirrors some of the metabolic effects of GLP-1 drugs, though at a gentler and slower level. 

For people who cannot tolerate GLP-1 agonists but have insulin resistance, maté may provide a low-risk metabolic support tool. 

How strong is the evidence? 

It is important to be honest: yerba maté is not equivalent to GLP-1 drugs in effect size. 

The weight loss observed in studies is typically modest; often a few kilograms over several months. But it is: 

Real + Reproducible + Achieved with minimal side effects + Associated with broader cardiometabolic benefits 

And crucially, maté can be used long-term without medicalisation, injections, or drug dependency. 

 Yerba Mate supplementation decreased body fat mass, percent body fat and waist-hip ratio [WHR]. Yerba Mate was a potent anti-obesity reagent that did not produce significant adverse effects. These results suggested that Yerba Mate supplementation may be effective for treating obese individuals.¹ 

YM selectively upregulates GLP-1 pathways without affecting GIP, likely through gut-mediated mechanisms. These findings suggest YM as a promising nutraceutical for incretin modulation and metabolic disorder management.²  

Weight loss can be frustrating, but we must never forget to make sure our bodies get the minerals and proteins they need for healthy function. Herbs can be a simple and safe way to look after our health, and something that many people trivialise because they do not understand the complexity and effectiveness of plant-based therapeutics. 

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_{¹Kim, SY., Oh, MR., Kim, MG., Chae, HJ. & Chae, SW. (2015) ‘Antiobesity effects of Yerba Mate (Ilex paraguariensis): A randomized, doubleblind, placebocontrolled clinical trial’, BMC Complementary and Alternative Medicine, 15, p. 338. doi: 10.1186/s1290601508591.} 

_{²CooperLeavitt, E.T., Shin, M.J., Beus, C.G., Chiu, A.T., Parker, G., Radford, J.H., Evans, E.P., Edwards, I.T., Arroyo, J.A., Reynolds, P.R. & Bikman, B.T. (2025) ‘The incretin effect of Yerba Maté (Ilex paraguariensis) is partially dependent on gutmediated metabolism of ferulic acid’, Nutrients, 17(4), p. 625. doi: 10.3390/nu17040625.} 

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