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Raspberry Ketone: The Ingredient With No Human Trial

By the SodaSlim Team · Published 19 September 2026 · Last updated September 2026 · 8-minute read · Reviewed by Dr. Aimee Duffy, MD

What raspberry ketone is sold as

Raspberry ketone is the aromatic compound that gives red raspberries their smell. Chemically it resembles synephrine and capsaicin, both of which do affect fat metabolism, and that resemblance is the origin of its entire commercial career.

On a supplement label it is usually described as helping to break down fat cells so the body can use them. SodaSlim's own seller describes it as a natural compound that facilitates the breakdown of fat cells, making them easier for your metabolism to burn.

This desk sells a capsule that contains it. What follows is an account of the evidence, written because a reader deciding between two bottles deserves to know which of the names on each one is doing work and which is decoration.

What its own review says

The most efficient way into this literature is to read what the people who reviewed it concluded.

A 2021 review in Plants surveys the pharmacological work on the compound and states, in its own abstract, that in spite of a lack of reliable human research it is marketed as a health supplement at very high doses. It also notes that although rodent studies have demonstrated efficacious effects, the mechanism remains largely unknown, and calls for work before the compound can be considered safe and efficacious.

That is not a hostile source. It is a review of raspberry ketone, in a journal about plants, by authors with an interest in the compound, and it is the clearest single sentence available about the state of the evidence.

The rodent and cell evidence, described properly

There is real work here and it is worth describing accurately rather than dismissing.

• A 2022 study in 3T3-L1 adipocytes, a mouse fat-cell line, reported that raspberry ketone promotes FNDC5 protein expression through HO-1 upregulation. FNDC5 is the precursor of irisin, which is part of the browning story for fat tissue.
• A 2024 study in mice on a high-fat diet reported an ameliorating effect on hypothalamic inflammation.
• A 2020 study in mice looked at meal patterns and cardiovascular parameters and found the effects differed depending on which outcome was measured, which is a more nuanced result than the marketing suggests.

None of those is a human result. Cell lines are a screening tool, mice are not small people, and the history of obesity pharmacology is largely a history of compounds that worked in rodents and did nothing in humans. A rodent result is a reason to run a human trial, not a substitute for having run one.

The two human studies, and why neither counts

Two human studies are routinely cited for raspberry ketone, and both tested products rather than the compound.

Lopez and colleagues, 2013, ran eight weeks in 70 obese but otherwise healthy adults using a multi-ingredient supplement containing raspberry ketone together with caffeine, capsaicin, garlic, ginger and Citrus aurantium, alongside a calorie-restricted diet and exercise training. Of the 45 who completed it, the supplement group lost 2.0 per cent of body weight against 0.5 per cent for placebo, with differences in fat mass, lean mass, waist and hip girth and self-reported energy.

Arent and colleagues, 2018, did something structurally similar with a different multi-ingredient product in overweight adults, again combined with exercise and diet.

Both are perfectly reasonable studies of the products they tested. Neither can tell you anything about raspberry ketone, because the arm contained six or more active ingredients plus a diet plus a training programme. Caffeine alone is in both formulas and has an independent literature behind it; attributing the result to the ketone is a choice made by whoever is quoting the paper.

This is the whole human literature on the ingredient as of writing.

The dose problem nobody can solve

Even if you accept the rodent work as suggestive, there is a second problem that does not go away.

The rodent studies use doses per kilogram of body weight that scale to amounts far beyond anything a capsule delivers. The 2021 review makes the point that the compound is marketed at very high doses, and a capsule containing four other ingredients cannot be delivering a high dose of any of them.

And on this particular label there is a third layer: no amount is printed at all. So the question is not whether the capsule contains enough raspberry ketone to reproduce a rodent result. It is that nobody outside the factory can say what it contains, and the rodent result would not transfer even if they could.

How common this is in the category

It would be unfair to single this ingredient out as though it were unusual.

A 2021 systematic review screened 20,504 citations to find 315 randomised trials of 14 supplements or therapies for weight loss. Only 52 were judged low risk of bias with sufficient data, and of those, 16 showed a significant between-group difference, ranging from 0.3 kg to 4.93 kg. The authors' conclusion is that the category has a limited high-quality evidence base and that practitioners and patients should be aware of the evidence behind claims before recommending use.

Raspberry ketone sits at the thin end of a thin category. What is unusual is not that its evidence is weak; it is that its evidence in humans, as a single ingredient, does not exist.

The fairest thing that can be said for it

Three things, and this desk would rather print them than pretend the ingredient has nothing going for it.

1. It has a plausible mechanism, established in cells and rodents, with a named pathway rather than a hand-wave.
2. It is not known to be harmful at the amounts found in supplements. The absence of trials cuts both ways, and no safety signal has emerged of the kind that attaches to some other ingredients in this category.
3. It is one of five ingredients in this capsule, not the whole formula. Two of the other four have real literatures at known amounts, which is where any effect this product has is most likely to come from.

How to spot it doing the selling

There is a difference between an ingredient that appears on a label and an ingredient that a product is being sold on, and it is usually visible in the layout rather than in the words.

• Position on the front. An ingredient named first, or given its own line, is carrying the pitch. On this bottle raspberry ketone is third of five, in an ordinary list.
• The product name. A capsule called something with “ketone” in it is being sold on one compound, and that compound has no human trial.
• Where the photography points. Berries in the imagery are an argument about an ingredient made without words.
• What the mechanism paragraph leads with. If the seller's description opens with fat-cell breakdown rather than with a stimulant, the ketone is doing the persuading.
• Whether an amount is printed. An ingredient a manufacturer is proud of usually has a number beside it. None of the five here does.

Applied to SodaSlim, the answer is mixed: the ketone is a middle entry on a five-name list, the product is not named after it, and the seller's own ingredient copy gives it a paragraph of the same length as the others. It is being used as furniture rather than as the pitch, which is the least bad way for an ingredient with this evidence base to appear on a label.

The verdict

If raspberry ketone is the reason you are considering a product, reconsider. There is no human trial of the compound on its own, its own review says reliable human research is lacking, and the two human studies that contain it tested six-ingredient and nine-ingredient products alongside supervised diets.

If it is one name among five on a label you are buying for other reasons, treat it as neutral: unlikely to be doing much, not known to be doing harm, and not a reason to choose or reject the bottle.

What it should never be is the headline. A product sold on raspberry ketone is a product sold on a rodent literature and a chemical resemblance, and a reader who knows that is much harder to sell to.