Studies & science

One key point upfront: research on individual ingredients is not proof that any specific product will deliver the same outcome. Studies depend on dose, duration, participant group, diet, activity levels and many other variables. That’s why we stick to the language of good science: signals, associations, effect sizes and limitations — not promises.

📌 How to read the evidence (short, but crucial)

When weight and “slimming goals” come up, the biggest mistake is turning a headline into a guarantee. Research simply doesn’t work like that:

So if someone tells you an ingredient “automatically makes you lose weight”, healthy scepticism is sensible. Good evidence is rarely that neat — but it’s far more honest.

🍵 Green tea extract (Camellia sinensis), incl. EGCG: what the research actually shows

Green tea catechins — particularly EGCG — have been studied for years in relation to body composition and metabolic outcomes. The headline from recent evidence syntheses is fairly consistent: if effects on weight or measurements show up at all, they tend to be modest, and they vary with study design, dose and intervention length.

A dose–response meta-analysis of randomised trials (Lin et al., 2020) reported improvements in certain obesity-related measures, but results weren’t uniform across settings and differed by dose and duration (PubMed: Lin et al., 2020).
A more recent, GRADE-assessed meta-analysis also found average reductions in body weight, BMI and body fat percentage, while other outcomes (such as waist measures) were not consistently improved — a good reminder that nutrition evidence is often nuanced (PubMed: Asbaghi et al., 2024).

What you can fairly conclude: green tea extract has been studied in humans in the context of weight and body fat; any average changes reported are typically small and not always reproduced across all trials. That variability is common in nutrition interventions.

⚠️ Safety: why dose context matters

With concentrated catechins (as found in extracts), dose deserves particular attention. The European Food Safety Authority (EFSA) reviewed green tea catechins and noted that very high intakes from supplements (especially around 800 mg/day EGCG and above) have been associated with a risk of liver injury in some cases; at the same time, normal consumption from traditional green tea infusions is generally considered safe (EFSA Scientific Opinion, 2018; EFSA News, 2018).

🧬 Berberine (from Berberis aristata): evidence on body measures and metabolic markers

Berberine is an alkaloid frequently studied in clinical research, often in relation to metabolic markers (such as glucose and lipid parameters) and anthropometric outcomes. This is exactly where meta-analyses are useful, because individual trials can be mixed.

A meta-analysis (Asbaghi et al., 2020) reported average reductions in body weight, BMI and waist circumference with berberine supplementation, while emphasising substantial variability between studies (population, duration, dose) (PubMed: Asbaghi et al., 2020).
Another systematic review and meta-analysis focusing on “obesity indices” reached a similar overall direction of effect, but again highlighted inconsistency across the literature (PubMed: Xiong et al., 2020).

The honest limitation: many human trials use berberine doses that are much higher (often several hundred milligrams per day) and run for weeks to months. It’s methodologically unsound to assume the same magnitude of effect applies to substantially different dosing contexts. Good science separates what was studied from what’s being inferred.

🧠 Mechanisms (briefly — without over-selling the theory)

Reviews discuss berberine as “multi-target”, including AMPK-related pathways and hypotheses around the gut microbiome. Mechanistic explanations can sound compelling, but the decisive question remains: what do well-run clinical studies actually show? (PubMed: Ilyas et al., 2020).

🧾 Chromium (as chromium picolinate): the cleanest area for authorised claims

Chromium is the ingredient here with authorised health claims. Following EFSA’s assessment and the authorised claims framework (e.g., Regulation (EU) 432/2012 and its retained equivalents), the following statements are permitted when the conditions of use are met:

See EFSA’s scientific opinion (EFSA, 2010) and the authorised claims listing for the legal wording and conditions (EFSA Opinion: Chromium, 2010; UK legislation mirror of EU list).
Compliance note: such claims are only acceptable if the product meets the criteria (for example, being at least a source of chromium, as defined in the relevant rules).

⚖️ Chromium picolinate and weight loss: small and uncertain

There are meta-analyses on chromium picolinate and body weight. A frequently cited review (Pittler & Ernst, 2003) found a small average effect on weight, but questioned its clinical relevance and robustness (PubMed: Pittler et al., 2003).
A Cochrane review (Tian et al., 2013) took a stricter view and concluded there was insufficient reliable evidence to make clear statements about effectiveness and safety for weight reduction in overweight/obese adults (PubMed: Tian et al., 2013).

In plain terms: chromium’s strongest, legally authorised positioning sits in the metabolism-related claims, not in bold promises about weight loss.

🌿 Milk thistle (Silybum marianum) / silymarin: research around liver and metabolic markers

Silymarin has a long research history, particularly in studies relating to fatty liver disease (NAFLD, now often discussed under the broader term MASLD) and liver enzymes. That isn’t a “weight-loss shortcut”; it’s more about an organ deeply involved in metabolic processes.

Meta-analyses and reviews report, depending on the study set, improvements in liver enzymes and certain metabolic markers — while also noting that evidence certainty can range from moderate to low. Examples include:

Claim practicality: health claims for milk thistle/silymarin must be handled with care. That’s why this page describes research context only, not marketing promises.

🧪 “Liposomal”: what it means — and what it doesn’t

“Liposomal” describes a formulation approach where compounds are encapsulated in liposomes (tiny lipid vesicles). It’s explored as a technology to protect sensitive molecules and potentially influence how they behave in the body. But evidence is highly context-dependent: lab data, animal studies and formulation research do not automatically translate to meaningful human outcomes, and one product formulation isn’t interchangeable with another.

For berberine, preclinical and pharmaceutical studies suggest liposomal formulations can influence measured bioavailability (e.g., Duong et al., 2022; Sharma et al., 2024) — scientifically interesting, but not a substitute for robust human outcome data for a specific finished product (PubMed: Duong et al., 2022; PubMed: Sharma et al., 2024).
For green tea polyphenols, there’s also food-tech and stability-focused work on liposomal encapsulation, with the same caveat: formulation research is not the same as clinical proof of effect (PMC: Liposomes loaded with green tea polyphenols, 2023).

✅ A fair conclusion (without marketing fog)

If you spend time with the literature, the conclusions can feel less dramatic — but they’re more trustworthy. That’s the point of this page.

📚 References (selected)